TOMOYO Linux Cross Reference
Linux/arch/x86/kvm/svm/sev.c

   // SPDX-License-Identifier: GPL-2.0-only
   /*
    * Kernel-based Virtual Machine driver for Linux
    *
    * AMD SVM-SEV support
    *
    * Copyright 2010 Red Hat, Inc. and/or its affiliates.
    */
   #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/kvm_types.h>
  #include <linux/kvm_host.h>
  #include <linux/kernel.h>
  #include <linux/highmem.h>
  #include <linux/psp.h>
  #include <linux/psp-sev.h>
  #include <linux/pagemap.h>
  #include <linux/swap.h>
  #include <linux/misc_cgroup.h>
  #include <linux/processor.h>
  #include <linux/trace_events.h>
  #include <uapi/linux/sev-guest.h>
  
  #include <asm/pkru.h>
  #include <asm/trapnr.h>
  #include <asm/fpu/xcr.h>
  #include <asm/fpu/xstate.h>
  #include <asm/debugreg.h>
  #include <asm/sev.h>
  
  #include "mmu.h"
  #include "x86.h"
  #include "svm.h"
  #include "svm_ops.h"
  #include "cpuid.h"
  #include "trace.h"
  
  #define GHCB_VERSION_MAX        2ULL
  #define GHCB_VERSION_DEFAULT    2ULL
  #define GHCB_VERSION_MIN        1ULL
  
  #define GHCB_HV_FT_SUPPORTED    (GHCB_HV_FT_SNP | GHCB_HV_FT_SNP_AP_CREATION)
  
  /* enable/disable SEV support */
  static bool sev_enabled = true;
  module_param_named(sev, sev_enabled, bool, 0444);
  
  /* enable/disable SEV-ES support */
  static bool sev_es_enabled = true;
  module_param_named(sev_es, sev_es_enabled, bool, 0444);
  
  /* enable/disable SEV-SNP support */
  static bool sev_snp_enabled = true;
  module_param_named(sev_snp, sev_snp_enabled, bool, 0444);
  
  /* enable/disable SEV-ES DebugSwap support */
  static bool sev_es_debug_swap_enabled = true;
  module_param_named(debug_swap, sev_es_debug_swap_enabled, bool, 0444);
  static u64 sev_supported_vmsa_features;
  
  #define AP_RESET_HOLD_NONE              0
  #define AP_RESET_HOLD_NAE_EVENT         1
  #define AP_RESET_HOLD_MSR_PROTO         2
  
  /* As defined by SEV-SNP Firmware ABI, under "Guest Policy". */
  #define SNP_POLICY_MASK_API_MINOR       GENMASK_ULL(7, 0)
  #define SNP_POLICY_MASK_API_MAJOR       GENMASK_ULL(15, 8)
  #define SNP_POLICY_MASK_SMT             BIT_ULL(16)
  #define SNP_POLICY_MASK_RSVD_MBO        BIT_ULL(17)
  #define SNP_POLICY_MASK_DEBUG           BIT_ULL(19)
  #define SNP_POLICY_MASK_SINGLE_SOCKET   BIT_ULL(20)
  
  #define SNP_POLICY_MASK_VALID           (SNP_POLICY_MASK_API_MINOR      | \
                                           SNP_POLICY_MASK_API_MAJOR      | \
                                           SNP_POLICY_MASK_SMT            | \
                                           SNP_POLICY_MASK_RSVD_MBO       | \
                                           SNP_POLICY_MASK_DEBUG          | \
                                           SNP_POLICY_MASK_SINGLE_SOCKET)
  
  #define INITIAL_VMSA_GPA 0xFFFFFFFFF000
  
  static u8 sev_enc_bit;
  static DECLARE_RWSEM(sev_deactivate_lock);
  static DEFINE_MUTEX(sev_bitmap_lock);
  unsigned int max_sev_asid;
  static unsigned int min_sev_asid;
  static unsigned long sev_me_mask;
  static unsigned int nr_asids;
  static unsigned long *sev_asid_bitmap;
  static unsigned long *sev_reclaim_asid_bitmap;
  
  static int snp_decommission_context(struct kvm *kvm);
  
  struct enc_region {
          struct list_head list;
          unsigned long npages;
          struct page **pages;
          unsigned long uaddr;
          unsigned long size;
 };
 
 /* Called with the sev_bitmap_lock held, or on shutdown  */
 static int sev_flush_asids(unsigned int min_asid, unsigned int max_asid)
 {
         int ret, error = 0;
         unsigned int asid;
 
         /* Check if there are any ASIDs to reclaim before performing a flush */
         asid = find_next_bit(sev_reclaim_asid_bitmap, nr_asids, min_asid);
         if (asid > max_asid)
                 return -EBUSY;
 
         /*
          * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail,
          * so it must be guarded.
          */
         down_write(&sev_deactivate_lock);
 
         wbinvd_on_all_cpus();
 
         if (sev_snp_enabled)
                 ret = sev_do_cmd(SEV_CMD_SNP_DF_FLUSH, NULL, &error);
         else
                 ret = sev_guest_df_flush(&error);
 
         up_write(&sev_deactivate_lock);
 
         if (ret)
                 pr_err("SEV%s: DF_FLUSH failed, ret=%d, error=%#x\n",
                        sev_snp_enabled ? "-SNP" : "", ret, error);
 
         return ret;
 }
 
 static inline bool is_mirroring_enc_context(struct kvm *kvm)
 {
         return !!to_kvm_sev_info(kvm)->enc_context_owner;
 }
 
 static bool sev_vcpu_has_debug_swap(struct vcpu_svm *svm)
 {
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
 
         return sev->vmsa_features & SVM_SEV_FEAT_DEBUG_SWAP;
 }
 
 /* Must be called with the sev_bitmap_lock held */
 static bool __sev_recycle_asids(unsigned int min_asid, unsigned int max_asid)
 {
         if (sev_flush_asids(min_asid, max_asid))
                 return false;
 
         /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */
         bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap,
                    nr_asids);
         bitmap_zero(sev_reclaim_asid_bitmap, nr_asids);
 
         return true;
 }
 
 static int sev_misc_cg_try_charge(struct kvm_sev_info *sev)
 {
         enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
         return misc_cg_try_charge(type, sev->misc_cg, 1);
 }
 
 static void sev_misc_cg_uncharge(struct kvm_sev_info *sev)
 {
         enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
         misc_cg_uncharge(type, sev->misc_cg, 1);
 }
 
 static int sev_asid_new(struct kvm_sev_info *sev)
 {
         /*
          * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid.
          * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1.
          * Note: min ASID can end up larger than the max if basic SEV support is
          * effectively disabled by disallowing use of ASIDs for SEV guests.
          */
         unsigned int min_asid = sev->es_active ? 1 : min_sev_asid;
         unsigned int max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid;
         unsigned int asid;
         bool retry = true;
         int ret;
 
         if (min_asid > max_asid)
                 return -ENOTTY;
 
         WARN_ON(sev->misc_cg);
         sev->misc_cg = get_current_misc_cg();
         ret = sev_misc_cg_try_charge(sev);
         if (ret) {
                 put_misc_cg(sev->misc_cg);
                 sev->misc_cg = NULL;
                 return ret;
         }
 
         mutex_lock(&sev_bitmap_lock);
 
 again:
         asid = find_next_zero_bit(sev_asid_bitmap, max_asid + 1, min_asid);
         if (asid > max_asid) {
                 if (retry && __sev_recycle_asids(min_asid, max_asid)) {
                         retry = false;
                         goto again;
                 }
                 mutex_unlock(&sev_bitmap_lock);
                 ret = -EBUSY;
                 goto e_uncharge;
         }
 
         __set_bit(asid, sev_asid_bitmap);
 
         mutex_unlock(&sev_bitmap_lock);
 
         sev->asid = asid;
         return 0;
 e_uncharge:
         sev_misc_cg_uncharge(sev);
         put_misc_cg(sev->misc_cg);
         sev->misc_cg = NULL;
         return ret;
 }
 
 static unsigned int sev_get_asid(struct kvm *kvm)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 
         return sev->asid;
 }
 
 static void sev_asid_free(struct kvm_sev_info *sev)
 {
         struct svm_cpu_data *sd;
         int cpu;
 
         mutex_lock(&sev_bitmap_lock);
 
         __set_bit(sev->asid, sev_reclaim_asid_bitmap);
 
         for_each_possible_cpu(cpu) {
                 sd = per_cpu_ptr(&svm_data, cpu);
                 sd->sev_vmcbs[sev->asid] = NULL;
         }
 
         mutex_unlock(&sev_bitmap_lock);
 
         sev_misc_cg_uncharge(sev);
         put_misc_cg(sev->misc_cg);
         sev->misc_cg = NULL;
 }
 
 static void sev_decommission(unsigned int handle)
 {
         struct sev_data_decommission decommission;
 
         if (!handle)
                 return;
 
         decommission.handle = handle;
         sev_guest_decommission(&decommission, NULL);
 }
 
 /*
  * Transition a page to hypervisor-owned/shared state in the RMP table. This
  * should not fail under normal conditions, but leak the page should that
  * happen since it will no longer be usable by the host due to RMP protections.
  */
 static int kvm_rmp_make_shared(struct kvm *kvm, u64 pfn, enum pg_level level)
 {
         if (KVM_BUG_ON(rmp_make_shared(pfn, level), kvm)) {
                 snp_leak_pages(pfn, page_level_size(level) >> PAGE_SHIFT);
                 return -EIO;
         }
 
         return 0;
 }
 
 /*
  * Certain page-states, such as Pre-Guest and Firmware pages (as documented
  * in Chapter 5 of the SEV-SNP Firmware ABI under "Page States") cannot be
  * directly transitioned back to normal/hypervisor-owned state via RMPUPDATE
  * unless they are reclaimed first.
  *
  * Until they are reclaimed and subsequently transitioned via RMPUPDATE, they
  * might not be usable by the host due to being set as immutable or still
  * being associated with a guest ASID.
  *
  * Bug the VM and leak the page if reclaim fails, or if the RMP entry can't be
  * converted back to shared, as the page is no longer usable due to RMP
  * protections, and it's infeasible for the guest to continue on.
  */
 static int snp_page_reclaim(struct kvm *kvm, u64 pfn)
 {
         struct sev_data_snp_page_reclaim data = {0};
         int fw_err, rc;
 
         data.paddr = __sme_set(pfn << PAGE_SHIFT);
         rc = sev_do_cmd(SEV_CMD_SNP_PAGE_RECLAIM, &data, &fw_err);
         if (KVM_BUG(rc, kvm, "Failed to reclaim PFN %llx, rc %d fw_err %d", pfn, rc, fw_err)) {
                 snp_leak_pages(pfn, 1);
                 return -EIO;
         }
 
         if (kvm_rmp_make_shared(kvm, pfn, PG_LEVEL_4K))
                 return -EIO;
 
         return rc;
 }
 
 static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
 {
         struct sev_data_deactivate deactivate;
 
         if (!handle)
                 return;
 
         deactivate.handle = handle;
 
         /* Guard DEACTIVATE against WBINVD/DF_FLUSH used in ASID recycling */
         down_read(&sev_deactivate_lock);
         sev_guest_deactivate(&deactivate, NULL);
         up_read(&sev_deactivate_lock);
 
         sev_decommission(handle);
 }
 
 /*
  * This sets up bounce buffers/firmware pages to handle SNP Guest Request
  * messages (e.g. attestation requests). See "SNP Guest Request" in the GHCB
  * 2.0 specification for more details.
  *
  * Technically, when an SNP Guest Request is issued, the guest will provide its
  * own request/response pages, which could in theory be passed along directly
  * to firmware rather than using bounce pages. However, these pages would need
  * special care:
  *
  *   - Both pages are from shared guest memory, so they need to be protected
  *     from migration/etc. occurring while firmware reads/writes to them. At a
  *     minimum, this requires elevating the ref counts and potentially needing
  *     an explicit pinning of the memory. This places additional restrictions
  *     on what type of memory backends userspace can use for shared guest
  *     memory since there is some reliance on using refcounted pages.
  *
  *   - The response page needs to be switched to Firmware-owned[1] state
  *     before the firmware can write to it, which can lead to potential
  *     host RMP #PFs if the guest is misbehaved and hands the host a
  *     guest page that KVM might write to for other reasons (e.g. virtio
  *     buffers/etc.).
  *
  * Both of these issues can be avoided completely by using separately-allocated
  * bounce pages for both the request/response pages and passing those to
  * firmware instead. So that's what is being set up here.
  *
  * Guest requests rely on message sequence numbers to ensure requests are
  * issued to firmware in the order the guest issues them, so concurrent guest
  * requests generally shouldn't happen. But a misbehaved guest could issue
  * concurrent guest requests in theory, so a mutex is used to serialize
  * access to the bounce buffers.
  *
  * [1] See the "Page States" section of the SEV-SNP Firmware ABI for more
  *     details on Firmware-owned pages, along with "RMP and VMPL Access Checks"
  *     in the APM for details on the related RMP restrictions.
  */
 static int snp_guest_req_init(struct kvm *kvm)
 {
         struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
         struct page *req_page;
 
         req_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
         if (!req_page)
                 return -ENOMEM;
 
         sev->guest_resp_buf = snp_alloc_firmware_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
         if (!sev->guest_resp_buf) {
                 __free_page(req_page);
                 return -EIO;
         }
 
         sev->guest_req_buf = page_address(req_page);
         mutex_init(&sev->guest_req_mutex);
 
         return 0;
 }
 
 static void snp_guest_req_cleanup(struct kvm *kvm)
 {
         struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
 
         if (sev->guest_resp_buf)
                 snp_free_firmware_page(sev->guest_resp_buf);
 
         if (sev->guest_req_buf)
                 __free_page(virt_to_page(sev->guest_req_buf));
 
         sev->guest_req_buf = NULL;
         sev->guest_resp_buf = NULL;
 }
 
 static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
                             struct kvm_sev_init *data,
                             unsigned long vm_type)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_platform_init_args init_args = {0};
         bool es_active = vm_type != KVM_X86_SEV_VM;
         u64 valid_vmsa_features = es_active ? sev_supported_vmsa_features : 0;
         int ret;
 
         if (kvm->created_vcpus)
                 return -EINVAL;
 
         if (data->flags)
                 return -EINVAL;
 
         if (data->vmsa_features & ~valid_vmsa_features)
                 return -EINVAL;
 
         if (data->ghcb_version > GHCB_VERSION_MAX || (!es_active && data->ghcb_version))
                 return -EINVAL;
 
         if (unlikely(sev->active))
                 return -EINVAL;
 
         sev->active = true;
         sev->es_active = es_active;
         sev->vmsa_features = data->vmsa_features;
         sev->ghcb_version = data->ghcb_version;
 
         /*
          * Currently KVM supports the full range of mandatory features defined
          * by version 2 of the GHCB protocol, so default to that for SEV-ES
          * guests created via KVM_SEV_INIT2.
          */
         if (sev->es_active && !sev->ghcb_version)
                 sev->ghcb_version = GHCB_VERSION_DEFAULT;
 
         if (vm_type == KVM_X86_SNP_VM)
                 sev->vmsa_features |= SVM_SEV_FEAT_SNP_ACTIVE;
 
         ret = sev_asid_new(sev);
         if (ret)
                 goto e_no_asid;
 
         init_args.probe = false;
         ret = sev_platform_init(&init_args);
         if (ret)
                 goto e_free;
 
         /* This needs to happen after SEV/SNP firmware initialization. */
         if (vm_type == KVM_X86_SNP_VM && snp_guest_req_init(kvm))
                 goto e_free;
 
         INIT_LIST_HEAD(&sev->regions_list);
         INIT_LIST_HEAD(&sev->mirror_vms);
         sev->need_init = false;
 
         kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_SEV);
 
         return 0;
 
 e_free:
         argp->error = init_args.error;
         sev_asid_free(sev);
         sev->asid = 0;
 e_no_asid:
         sev->vmsa_features = 0;
         sev->es_active = false;
         sev->active = false;
         return ret;
 }
 
 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_init data = {
                 .vmsa_features = 0,
                 .ghcb_version = 0,
         };
         unsigned long vm_type;
 
         if (kvm->arch.vm_type != KVM_X86_DEFAULT_VM)
                 return -EINVAL;
 
         vm_type = (argp->id == KVM_SEV_INIT ? KVM_X86_SEV_VM : KVM_X86_SEV_ES_VM);
 
         /*
          * KVM_SEV_ES_INIT has been deprecated by KVM_SEV_INIT2, so it will
          * continue to only ever support the minimal GHCB protocol version.
          */
         if (vm_type == KVM_X86_SEV_ES_VM)
                 data.ghcb_version = GHCB_VERSION_MIN;
 
         return __sev_guest_init(kvm, argp, &data, vm_type);
 }
 
 static int sev_guest_init2(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct kvm_sev_init data;
 
         if (!sev->need_init)
                 return -EINVAL;
 
         if (kvm->arch.vm_type != KVM_X86_SEV_VM &&
             kvm->arch.vm_type != KVM_X86_SEV_ES_VM &&
             kvm->arch.vm_type != KVM_X86_SNP_VM)
                 return -EINVAL;
 
         if (copy_from_user(&data, u64_to_user_ptr(argp->data), sizeof(data)))
                 return -EFAULT;
 
         return __sev_guest_init(kvm, argp, &data, kvm->arch.vm_type);
 }
 
 static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
 {
         unsigned int asid = sev_get_asid(kvm);
         struct sev_data_activate activate;
         int ret;
 
         /* activate ASID on the given handle */
         activate.handle = handle;
         activate.asid   = asid;
         ret = sev_guest_activate(&activate, error);
 
         return ret;
 }
 
 static int __sev_issue_cmd(int fd, int id, void *data, int *error)
 {
         struct fd f;
         int ret;
 
         f = fdget(fd);
         if (!f.file)
                 return -EBADF;
 
         ret = sev_issue_cmd_external_user(f.file, id, data, error);
 
         fdput(f);
         return ret;
 }
 
 static int sev_issue_cmd(struct kvm *kvm, int id, void *data, int *error)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 
         return __sev_issue_cmd(sev->fd, id, data, error);
 }
 
 static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_launch_start start;
         struct kvm_sev_launch_start params;
         void *dh_blob, *session_blob;
         int *error = &argp->error;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         memset(&start, 0, sizeof(start));
 
         dh_blob = NULL;
         if (params.dh_uaddr) {
                 dh_blob = psp_copy_user_blob(params.dh_uaddr, params.dh_len);
                 if (IS_ERR(dh_blob))
                         return PTR_ERR(dh_blob);
 
                 start.dh_cert_address = __sme_set(__pa(dh_blob));
                 start.dh_cert_len = params.dh_len;
         }
 
         session_blob = NULL;
         if (params.session_uaddr) {
                 session_blob = psp_copy_user_blob(params.session_uaddr, params.session_len);
                 if (IS_ERR(session_blob)) {
                         ret = PTR_ERR(session_blob);
                         goto e_free_dh;
                 }
 
                 start.session_address = __sme_set(__pa(session_blob));
                 start.session_len = params.session_len;
         }
 
         start.handle = params.handle;
         start.policy = params.policy;
 
         /* create memory encryption context */
         ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, &start, error);
         if (ret)
                 goto e_free_session;
 
         /* Bind ASID to this guest */
         ret = sev_bind_asid(kvm, start.handle, error);
         if (ret) {
                 sev_decommission(start.handle);
                 goto e_free_session;
         }
 
         /* return handle to userspace */
         params.handle = start.handle;
         if (copy_to_user(u64_to_user_ptr(argp->data), &params, sizeof(params))) {
                 sev_unbind_asid(kvm, start.handle);
                 ret = -EFAULT;
                 goto e_free_session;
         }
 
         sev->handle = start.handle;
         sev->fd = argp->sev_fd;
 
 e_free_session:
         kfree(session_blob);
 e_free_dh:
         kfree(dh_blob);
         return ret;
 }
 
 static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
                                     unsigned long ulen, unsigned long *n,
                                     int write)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         unsigned long npages, size;
         int npinned;
         unsigned long locked, lock_limit;
         struct page **pages;
         unsigned long first, last;
         int ret;
 
         lockdep_assert_held(&kvm->lock);
 
         if (ulen == 0 || uaddr + ulen < uaddr)
                 return ERR_PTR(-EINVAL);
 
         /* Calculate number of pages. */
         first = (uaddr & PAGE_MASK) >> PAGE_SHIFT;
         last = ((uaddr + ulen - 1) & PAGE_MASK) >> PAGE_SHIFT;
         npages = (last - first + 1);
 
         locked = sev->pages_locked + npages;
         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
         if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
                 pr_err("SEV: %lu locked pages exceed the lock limit of %lu.\n", locked, lock_limit);
                 return ERR_PTR(-ENOMEM);
         }
 
         if (WARN_ON_ONCE(npages > INT_MAX))
                 return ERR_PTR(-EINVAL);
 
         /* Avoid using vmalloc for smaller buffers. */
         size = npages * sizeof(struct page *);
         if (size > PAGE_SIZE)
                 pages = __vmalloc(size, GFP_KERNEL_ACCOUNT);
         else
                 pages = kmalloc(size, GFP_KERNEL_ACCOUNT);
 
         if (!pages)
                 return ERR_PTR(-ENOMEM);
 
         /* Pin the user virtual address. */
         npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);
         if (npinned != npages) {
                 pr_err("SEV: Failure locking %lu pages.\n", npages);
                 ret = -ENOMEM;
                 goto err;
         }
 
         *n = npages;
         sev->pages_locked = locked;
 
         return pages;
 
 err:
         if (npinned > 0)
                 unpin_user_pages(pages, npinned);
 
         kvfree(pages);
         return ERR_PTR(ret);
 }
 
 static void sev_unpin_memory(struct kvm *kvm, struct page **pages,
                              unsigned long npages)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 
         unpin_user_pages(pages, npages);
         kvfree(pages);
         sev->pages_locked -= npages;
 }
 
 static void sev_clflush_pages(struct page *pages[], unsigned long npages)
 {
         uint8_t *page_virtual;
         unsigned long i;
 
         if (this_cpu_has(X86_FEATURE_SME_COHERENT) || npages == 0 ||
             pages == NULL)
                 return;
 
         for (i = 0; i < npages; i++) {
                 page_virtual = kmap_local_page(pages[i]);
                 clflush_cache_range(page_virtual, PAGE_SIZE);
                 kunmap_local(page_virtual);
                 cond_resched();
         }
 }
 
 static unsigned long get_num_contig_pages(unsigned long idx,
                                 struct page **inpages, unsigned long npages)
 {
         unsigned long paddr, next_paddr;
         unsigned long i = idx + 1, pages = 1;
 
         /* find the number of contiguous pages starting from idx */
         paddr = __sme_page_pa(inpages[idx]);
         while (i < npages) {
                 next_paddr = __sme_page_pa(inpages[i++]);
                 if ((paddr + PAGE_SIZE) == next_paddr) {
                         pages++;
                         paddr = next_paddr;
                         continue;
                 }
                 break;
         }
 
         return pages;
 }
 
 static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct kvm_sev_launch_update_data params;
         struct sev_data_launch_update_data data;
         struct page **inpages;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         vaddr = params.uaddr;
         size = params.len;
         vaddr_end = vaddr + size;
 
         /* Lock the user memory. */
         inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
         if (IS_ERR(inpages))
                 return PTR_ERR(inpages);
 
         /*
          * Flush (on non-coherent CPUs) before LAUNCH_UPDATE encrypts pages in
          * place; the cache may contain the data that was written unencrypted.
          */
         sev_clflush_pages(inpages, npages);
 
         data.reserved = 0;
         data.handle = sev->handle;
 
         for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) {
                 int offset, len;
 
                 /*
                  * If the user buffer is not page-aligned, calculate the offset
                  * within the page.
                  */
                 offset = vaddr & (PAGE_SIZE - 1);
 
                 /* Calculate the number of pages that can be encrypted in one go. */
                 pages = get_num_contig_pages(i, inpages, npages);
 
                 len = min_t(size_t, ((pages * PAGE_SIZE) - offset), size);
 
                 data.len = len;
                 data.address = __sme_page_pa(inpages[i]) + offset;
                 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_DATA, &data, &argp->error);
                 if (ret)
                         goto e_unpin;
 
                 size -= len;
                 next_vaddr = vaddr + len;
         }
 
 e_unpin:
         /* content of memory is updated, mark pages dirty */
         for (i = 0; i < npages; i++) {
                 set_page_dirty_lock(inpages[i]);
                 mark_page_accessed(inpages[i]);
         }
         /* unlock the user pages */
         sev_unpin_memory(kvm, inpages, npages);
         return ret;
 }
 
 static int sev_es_sync_vmsa(struct vcpu_svm *svm)
 {
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
         struct sev_es_save_area *save = svm->sev_es.vmsa;
         struct xregs_state *xsave;
         const u8 *s;
         u8 *d;
         int i;
 
         /* Check some debug related fields before encrypting the VMSA */
         if (svm->vcpu.guest_debug || (svm->vmcb->save.dr7 & ~DR7_FIXED_1))
                 return -EINVAL;
 
         /*
          * SEV-ES will use a VMSA that is pointed to by the VMCB, not
          * the traditional VMSA that is part of the VMCB. Copy the
          * traditional VMSA as it has been built so far (in prep
          * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state.
          */
         memcpy(save, &svm->vmcb->save, sizeof(svm->vmcb->save));
 
         /* Sync registgers */
         save->rax = svm->vcpu.arch.regs[VCPU_REGS_RAX];
         save->rbx = svm->vcpu.arch.regs[VCPU_REGS_RBX];
         save->rcx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
         save->rdx = svm->vcpu.arch.regs[VCPU_REGS_RDX];
         save->rsp = svm->vcpu.arch.regs[VCPU_REGS_RSP];
         save->rbp = svm->vcpu.arch.regs[VCPU_REGS_RBP];
         save->rsi = svm->vcpu.arch.regs[VCPU_REGS_RSI];
         save->rdi = svm->vcpu.arch.regs[VCPU_REGS_RDI];
 #ifdef CONFIG_X86_64
         save->r8  = svm->vcpu.arch.regs[VCPU_REGS_R8];
         save->r9  = svm->vcpu.arch.regs[VCPU_REGS_R9];
         save->r10 = svm->vcpu.arch.regs[VCPU_REGS_R10];
         save->r11 = svm->vcpu.arch.regs[VCPU_REGS_R11];
         save->r12 = svm->vcpu.arch.regs[VCPU_REGS_R12];
         save->r13 = svm->vcpu.arch.regs[VCPU_REGS_R13];
         save->r14 = svm->vcpu.arch.regs[VCPU_REGS_R14];
         save->r15 = svm->vcpu.arch.regs[VCPU_REGS_R15];
 #endif
         save->rip = svm->vcpu.arch.regs[VCPU_REGS_RIP];
 
         /* Sync some non-GPR registers before encrypting */
         save->xcr0 = svm->vcpu.arch.xcr0;
         save->pkru = svm->vcpu.arch.pkru;
         save->xss  = svm->vcpu.arch.ia32_xss;
         save->dr6  = svm->vcpu.arch.dr6;
 
         save->sev_features = sev->vmsa_features;
 
         /*
          * Skip FPU and AVX setup with KVM_SEV_ES_INIT to avoid
          * breaking older measurements.
          */
         if (vcpu->kvm->arch.vm_type != KVM_X86_DEFAULT_VM) {
                 xsave = &vcpu->arch.guest_fpu.fpstate->regs.xsave;
                 save->x87_dp = xsave->i387.rdp;
                 save->mxcsr = xsave->i387.mxcsr;
                 save->x87_ftw = xsave->i387.twd;
                 save->x87_fsw = xsave->i387.swd;
                 save->x87_fcw = xsave->i387.cwd;
                 save->x87_fop = xsave->i387.fop;
                 save->x87_ds = 0;
                 save->x87_cs = 0;
                 save->x87_rip = xsave->i387.rip;
 
                 for (i = 0; i < 8; i++) {
                         /*
                          * The format of the x87 save area is undocumented and
                          * definitely not what you would expect.  It consists of
                          * an 8*8 bytes area with bytes 0-7, and an 8*2 bytes
                          * area with bytes 8-9 of each register.
                          */
                         d = save->fpreg_x87 + i * 8;
                         s = ((u8 *)xsave->i387.st_space) + i * 16;
                         memcpy(d, s, 8);
                         save->fpreg_x87[64 + i * 2] = s[8];
                         save->fpreg_x87[64 + i * 2 + 1] = s[9];
                 }
                 memcpy(save->fpreg_xmm, xsave->i387.xmm_space, 256);
 
                 s = get_xsave_addr(xsave, XFEATURE_YMM);
                 if (s)
                         memcpy(save->fpreg_ymm, s, 256);
                 else
                         memset(save->fpreg_ymm, 0, 256);
         }
 
         pr_debug("Virtual Machine Save Area (VMSA):\n");
         print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, save, sizeof(*save), false);
 
         return 0;
 }
 
 static int __sev_launch_update_vmsa(struct kvm *kvm, struct kvm_vcpu *vcpu,
                                     int *error)
 {
         struct sev_data_launch_update_vmsa vmsa;
         struct vcpu_svm *svm = to_svm(vcpu);
         int ret;
 
         if (vcpu->guest_debug) {
                 pr_warn_once("KVM_SET_GUEST_DEBUG for SEV-ES guest is not supported");
                 return -EINVAL;
         }
 
         /* Perform some pre-encryption checks against the VMSA */
         ret = sev_es_sync_vmsa(svm);
         if (ret)
                 return ret;
 
         /*
          * The LAUNCH_UPDATE_VMSA command will perform in-place encryption of
          * the VMSA memory content (i.e it will write the same memory region
          * with the guest's key), so invalidate it first.
          */
         clflush_cache_range(svm->sev_es.vmsa, PAGE_SIZE);
 
         vmsa.reserved = 0;
         vmsa.handle = to_kvm_sev_info(kvm)->handle;
         vmsa.address = __sme_pa(svm->sev_es.vmsa);
         vmsa.len = PAGE_SIZE;
         ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_VMSA, &vmsa, error);
         if (ret)
           return ret;
 
         /*
          * SEV-ES guests maintain an encrypted version of their FPU
          * state which is restored and saved on VMRUN and VMEXIT.
          * Mark vcpu->arch.guest_fpu->fpstate as scratch so it won't
          * do xsave/xrstor on it.
          */
         fpstate_set_confidential(&vcpu->arch.guest_fpu);
         vcpu->arch.guest_state_protected = true;
 
         /*
          * SEV-ES guest mandates LBR Virtualization to be _always_ ON. Enable it
          * only after setting guest_state_protected because KVM_SET_MSRS allows
          * dynamic toggling of LBRV (for performance reason) on write access to
          * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.
          */
         svm_enable_lbrv(vcpu);
         return 0;
 }
 
 static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_vcpu *vcpu;
         unsigned long i;
         int ret;
 
         if (!sev_es_guest(kvm))
                 return -ENOTTY;
 
         kvm_for_each_vcpu(i, vcpu, kvm) {
                 ret = mutex_lock_killable(&vcpu->mutex);
                 if (ret)
                         return ret;
 
                 ret = __sev_launch_update_vmsa(kvm, vcpu, &argp->error);
 
                 mutex_unlock(&vcpu->mutex);
                 if (ret)
                         return ret;
         }
 
         return 0;
 }
 
 static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         void __user *measure = u64_to_user_ptr(argp->data);
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_launch_measure data;
         struct kvm_sev_launch_measure params;
         void __user *p = NULL;
         void *blob = NULL;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, measure, sizeof(params)))
                 return -EFAULT;
 
         memset(&data, 0, sizeof(data));
 
         /* User wants to query the blob length */
         if (!params.len)
                 goto cmd;
 
         p = u64_to_user_ptr(params.uaddr);
         if (p) {
                 if (params.len > SEV_FW_BLOB_MAX_SIZE)
                         return -EINVAL;
 
                 blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
                 if (!blob)
                         return -ENOMEM;
 
                 data.address = __psp_pa(blob);
                 data.len = params.len;
         }
 
 cmd:
         data.handle = sev->handle;
         ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_MEASURE, &data, &argp->error);
 
         /*
          * If we query the session length, FW responded with expected data.
          */
         if (!params.len)
                 goto done;
 
         if (ret)
                 goto e_free_blob;
 
         if (blob) {
                 if (copy_to_user(p, blob, params.len))
                         ret = -EFAULT;
         }
 
 done:
         params.len = data.len;
         if (copy_to_user(measure, &params, sizeof(params)))
                 ret = -EFAULT;
 e_free_blob:
         kfree(blob);
         return ret;
 }
 
 static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_launch_finish data;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         data.handle = sev->handle;
         return sev_issue_cmd(kvm, SEV_CMD_LAUNCH_FINISH, &data, &argp->error);
 }
 
 static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct kvm_sev_guest_status params;
         struct sev_data_guest_status data;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         memset(&data, 0, sizeof(data));
 
         data.handle = sev->handle;
         ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, &data, &argp->error);
         if (ret)
                 return ret;
 
         params.policy = data.policy;
         params.state = data.state;
         params.handle = data.handle;
 
         if (copy_to_user(u64_to_user_ptr(argp->data), &params, sizeof(params)))
                 ret = -EFAULT;
 
         return ret;
 }
 
 static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src,
                                unsigned long dst, int size,
                                int *error, bool enc)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_dbg data;
 
         data.reserved = 0;
         data.handle = sev->handle;
         data.dst_addr = dst;
         data.src_addr = src;
         data.len = size;
 
         return sev_issue_cmd(kvm,
                              enc ? SEV_CMD_DBG_ENCRYPT : SEV_CMD_DBG_DECRYPT,
                              &data, error);
 }
 
 static int __sev_dbg_decrypt(struct kvm *kvm, unsigned long src_paddr,
                              unsigned long dst_paddr, int sz, int *err)
 {
         int offset;
 
         /*
          * Its safe to read more than we are asked, caller should ensure that
          * destination has enough space.
          */
         offset = src_paddr & 15;
         src_paddr = round_down(src_paddr, 16);
         sz = round_up(sz + offset, 16);
 
         return __sev_issue_dbg_cmd(kvm, src_paddr, dst_paddr, sz, err, false);
 }
 
 static int __sev_dbg_decrypt_user(struct kvm *kvm, unsigned long paddr,
                                   void __user *dst_uaddr,
                                   unsigned long dst_paddr,
                                   int size, int *err)
 {
         struct page *tpage = NULL;
         int ret, offset;
 
         /* if inputs are not 16-byte then use intermediate buffer */
         if (!IS_ALIGNED(dst_paddr, 16) ||
             !IS_ALIGNED(paddr,     16) ||
             !IS_ALIGNED(size,      16)) {
                 tpage = (void *)alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
                 if (!tpage)
                         return -ENOMEM;
 
                 dst_paddr = __sme_page_pa(tpage);
         }
 
         ret = __sev_dbg_decrypt(kvm, paddr, dst_paddr, size, err);
         if (ret)
                 goto e_free;
 
         if (tpage) {
                 offset = paddr & 15;
                 if (copy_to_user(dst_uaddr, page_address(tpage) + offset, size))
                         ret = -EFAULT;
         }
 
 e_free:
         if (tpage)
                 __free_page(tpage);
 
         return ret;
 }
 
 static int __sev_dbg_encrypt_user(struct kvm *kvm, unsigned long paddr,
                                   void __user *vaddr,
                                   unsigned long dst_paddr,
                                   void __user *dst_vaddr,
                                   int size, int *error)
 {
         struct page *src_tpage = NULL;
         struct page *dst_tpage = NULL;
         int ret, len = size;
 
         /* If source buffer is not aligned then use an intermediate buffer */
         if (!IS_ALIGNED((unsigned long)vaddr, 16)) {
                 src_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
                 if (!src_tpage)
                         return -ENOMEM;
 
                 if (copy_from_user(page_address(src_tpage), vaddr, size)) {
                         __free_page(src_tpage);
                         return -EFAULT;
                 }
 
                 paddr = __sme_page_pa(src_tpage);
         }
 
         /*
          *  If destination buffer or length is not aligned then do read-modify-write:
          *   - decrypt destination in an intermediate buffer
          *   - copy the source buffer in an intermediate buffer
          *   - use the intermediate buffer as source buffer
          */
         if (!IS_ALIGNED((unsigned long)dst_vaddr, 16) || !IS_ALIGNED(size, 16)) {
                 int dst_offset;
 
                 dst_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
                 if (!dst_tpage) {
                         ret = -ENOMEM;
                         goto e_free;
                 }
 
                 ret = __sev_dbg_decrypt(kvm, dst_paddr,
                                         __sme_page_pa(dst_tpage), size, error);
                 if (ret)
                         goto e_free;
 
                 /*
                  *  If source is kernel buffer then use memcpy() otherwise
                  *  copy_from_user().
                  */
                 dst_offset = dst_paddr & 15;
 
                 if (src_tpage)
                         memcpy(page_address(dst_tpage) + dst_offset,
                                page_address(src_tpage), size);
                 else {
                         if (copy_from_user(page_address(dst_tpage) + dst_offset,
                                            vaddr, size)) {
                                 ret = -EFAULT;
                                 goto e_free;
                         }
                 }
 
                 paddr = __sme_page_pa(dst_tpage);
                 dst_paddr = round_down(dst_paddr, 16);
                 len = round_up(size, 16);
         }
 
         ret = __sev_issue_dbg_cmd(kvm, paddr, dst_paddr, len, error, true);
 
 e_free:
         if (src_tpage)
                 __free_page(src_tpage);
         if (dst_tpage)
                 __free_page(dst_tpage);
         return ret;
 }
 
 static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
 {
         unsigned long vaddr, vaddr_end, next_vaddr;
         unsigned long dst_vaddr;
         struct page **src_p, **dst_p;
         struct kvm_sev_dbg debug;
         unsigned long n;
         unsigned int size;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&debug, u64_to_user_ptr(argp->data), sizeof(debug)))
                 return -EFAULT;
 
         if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
                 return -EINVAL;
         if (!debug.dst_uaddr)
                 return -EINVAL;
 
         vaddr = debug.src_uaddr;
         size = debug.len;
         vaddr_end = vaddr + size;
         dst_vaddr = debug.dst_uaddr;
 
         for (; vaddr < vaddr_end; vaddr = next_vaddr) {
                 int len, s_off, d_off;
 
                 /* lock userspace source and destination page */
                 src_p = sev_pin_memory(kvm, vaddr & PAGE_MASK, PAGE_SIZE, &n, 0);
                 if (IS_ERR(src_p))
                         return PTR_ERR(src_p);
 
                 dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1);
                 if (IS_ERR(dst_p)) {
                         sev_unpin_memory(kvm, src_p, n);
                         return PTR_ERR(dst_p);
                 }
 
                 /*
                  * Flush (on non-coherent CPUs) before DBG_{DE,EN}CRYPT read or modify
                  * the pages; flush the destination too so that future accesses do not
                  * see stale data.
                  */
                 sev_clflush_pages(src_p, 1);
                 sev_clflush_pages(dst_p, 1);
 
                 /*
                  * Since user buffer may not be page aligned, calculate the
                  * offset within the page.
                  */
                 s_off = vaddr & ~PAGE_MASK;
                 d_off = dst_vaddr & ~PAGE_MASK;
                 len = min_t(size_t, (PAGE_SIZE - s_off), size);
 
                 if (dec)
                         ret = __sev_dbg_decrypt_user(kvm,
                                                      __sme_page_pa(src_p[0]) + s_off,
                                                      (void __user *)dst_vaddr,
                                                      __sme_page_pa(dst_p[0]) + d_off,
                                                      len, &argp->error);
                 else
                         ret = __sev_dbg_encrypt_user(kvm,
                                                      __sme_page_pa(src_p[0]) + s_off,
                                                      (void __user *)vaddr,
                                                      __sme_page_pa(dst_p[0]) + d_off,
                                                      (void __user *)dst_vaddr,
                                                      len, &argp->error);
 
                 sev_unpin_memory(kvm, src_p, n);
                 sev_unpin_memory(kvm, dst_p, n);
 
                 if (ret)
                         goto err;
 
                 next_vaddr = vaddr + len;
                 dst_vaddr = dst_vaddr + len;
                 size -= len;
         }
 err:
         return ret;
 }
 
 static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_launch_secret data;
         struct kvm_sev_launch_secret params;
         struct page **pages;
         void *blob, *hdr;
         unsigned long n, i;
         int ret, offset;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1);
         if (IS_ERR(pages))
                 return PTR_ERR(pages);
 
         /*
          * Flush (on non-coherent CPUs) before LAUNCH_SECRET encrypts pages in
          * place; the cache may contain the data that was written unencrypted.
          */
         sev_clflush_pages(pages, n);
 
         /*
          * The secret must be copied into contiguous memory region, lets verify
          * that userspace memory pages are contiguous before we issue command.
          */
         if (get_num_contig_pages(0, pages, n) != n) {
                 ret = -EINVAL;
                 goto e_unpin_memory;
         }
 
         memset(&data, 0, sizeof(data));
 
         offset = params.guest_uaddr & (PAGE_SIZE - 1);
         data.guest_address = __sme_page_pa(pages[0]) + offset;
         data.guest_len = params.guest_len;
 
         blob = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
         if (IS_ERR(blob)) {
                 ret = PTR_ERR(blob);
                 goto e_unpin_memory;
         }
 
         data.trans_address = __psp_pa(blob);
         data.trans_len = params.trans_len;
 
         hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
         if (IS_ERR(hdr)) {
                 ret = PTR_ERR(hdr);
                 goto e_free_blob;
         }
         data.hdr_address = __psp_pa(hdr);
         data.hdr_len = params.hdr_len;
 
         data.handle = sev->handle;
         ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, &data, &argp->error);
 
         kfree(hdr);
 
 e_free_blob:
         kfree(blob);
 e_unpin_memory:
         /* content of memory is updated, mark pages dirty */
         for (i = 0; i < n; i++) {
                 set_page_dirty_lock(pages[i]);
                 mark_page_accessed(pages[i]);
         }
         sev_unpin_memory(kvm, pages, n);
         return ret;
 }
 
 static int sev_get_attestation_report(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         void __user *report = u64_to_user_ptr(argp->data);
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_attestation_report data;
         struct kvm_sev_attestation_report params;
         void __user *p;
         void *blob = NULL;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         memset(&data, 0, sizeof(data));
 
         /* User wants to query the blob length */
         if (!params.len)
                 goto cmd;
 
         p = u64_to_user_ptr(params.uaddr);
         if (p) {
                 if (params.len > SEV_FW_BLOB_MAX_SIZE)
                         return -EINVAL;
 
                 blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
                 if (!blob)
                         return -ENOMEM;
 
                 data.address = __psp_pa(blob);
                 data.len = params.len;
                 memcpy(data.mnonce, params.mnonce, sizeof(params.mnonce));
         }
 cmd:
         data.handle = sev->handle;
         ret = sev_issue_cmd(kvm, SEV_CMD_ATTESTATION_REPORT, &data, &argp->error);
         /*
          * If we query the session length, FW responded with expected data.
          */
         if (!params.len)
                 goto done;
 
         if (ret)
                 goto e_free_blob;
 
         if (blob) {
                 if (copy_to_user(p, blob, params.len))
                         ret = -EFAULT;
         }
 
 done:
         params.len = data.len;
         if (copy_to_user(report, &params, sizeof(params)))
                 ret = -EFAULT;
 e_free_blob:
         kfree(blob);
         return ret;
 }
 
 /* Userspace wants to query session length. */
 static int
 __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp,
                                       struct kvm_sev_send_start *params)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_send_start data;
         int ret;
 
         memset(&data, 0, sizeof(data));
         data.handle = sev->handle;
         ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
 
         params->session_len = data.session_len;
         if (copy_to_user(u64_to_user_ptr(argp->data), params,
                                 sizeof(struct kvm_sev_send_start)))
                 ret = -EFAULT;
 
         return ret;
 }
 
 static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_send_start data;
         struct kvm_sev_send_start params;
         void *amd_certs, *session_data;
         void *pdh_cert, *plat_certs;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data),
                                 sizeof(struct kvm_sev_send_start)))
                 return -EFAULT;
 
         /* if session_len is zero, userspace wants to query the session length */
         if (!params.session_len)
                 return __sev_send_start_query_session_length(kvm, argp,
                                 &params);
 
         /* some sanity checks */
         if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
             !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE)
                 return -EINVAL;
 
         /* allocate the memory to hold the session data blob */
         session_data = kzalloc(params.session_len, GFP_KERNEL_ACCOUNT);
         if (!session_data)
                 return -ENOMEM;
 
         /* copy the certificate blobs from userspace */
         pdh_cert = psp_copy_user_blob(params.pdh_cert_uaddr,
                                 params.pdh_cert_len);
         if (IS_ERR(pdh_cert)) {
                 ret = PTR_ERR(pdh_cert);
                 goto e_free_session;
         }
 
         plat_certs = psp_copy_user_blob(params.plat_certs_uaddr,
                                 params.plat_certs_len);
         if (IS_ERR(plat_certs)) {
                 ret = PTR_ERR(plat_certs);
                 goto e_free_pdh;
         }
 
         amd_certs = psp_copy_user_blob(params.amd_certs_uaddr,
                                 params.amd_certs_len);
         if (IS_ERR(amd_certs)) {
                 ret = PTR_ERR(amd_certs);
                 goto e_free_plat_cert;
         }
 
         /* populate the FW SEND_START field with system physical address */
         memset(&data, 0, sizeof(data));
         data.pdh_cert_address = __psp_pa(pdh_cert);
         data.pdh_cert_len = params.pdh_cert_len;
         data.plat_certs_address = __psp_pa(plat_certs);
         data.plat_certs_len = params.plat_certs_len;
         data.amd_certs_address = __psp_pa(amd_certs);
         data.amd_certs_len = params.amd_certs_len;
         data.session_address = __psp_pa(session_data);
         data.session_len = params.session_len;
         data.handle = sev->handle;
 
         ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
 
         if (!ret && copy_to_user(u64_to_user_ptr(params.session_uaddr),
                         session_data, params.session_len)) {
                 ret = -EFAULT;
                 goto e_free_amd_cert;
         }
 
         params.policy = data.policy;
         params.session_len = data.session_len;
         if (copy_to_user(u64_to_user_ptr(argp->data), &params,
                                 sizeof(struct kvm_sev_send_start)))
                 ret = -EFAULT;
 
 e_free_amd_cert:
         kfree(amd_certs);
 e_free_plat_cert:
         kfree(plat_certs);
 e_free_pdh:
         kfree(pdh_cert);
 e_free_session:
         kfree(session_data);
         return ret;
 }
 
 /* Userspace wants to query either header or trans length. */
 static int
 __sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp,
                                      struct kvm_sev_send_update_data *params)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_send_update_data data;
         int ret;
 
         memset(&data, 0, sizeof(data));
         data.handle = sev->handle;
         ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
 
         params->hdr_len = data.hdr_len;
         params->trans_len = data.trans_len;
 
         if (copy_to_user(u64_to_user_ptr(argp->data), params,
                          sizeof(struct kvm_sev_send_update_data)))
                 ret = -EFAULT;
 
         return ret;
 }
 
 static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_send_update_data data;
         struct kvm_sev_send_update_data params;
         void *hdr, *trans_data;
         struct page **guest_page;
         unsigned long n;
         int ret, offset;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data),
                         sizeof(struct kvm_sev_send_update_data)))
                 return -EFAULT;
 
         /* userspace wants to query either header or trans length */
         if (!params.trans_len || !params.hdr_len)
                 return __sev_send_update_data_query_lengths(kvm, argp, &params);
 
         if (!params.trans_uaddr || !params.guest_uaddr ||
             !params.guest_len || !params.hdr_uaddr)
                 return -EINVAL;
 
         /* Check if we are crossing the page boundary */
         offset = params.guest_uaddr & (PAGE_SIZE - 1);
         if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
                 return -EINVAL;
 
         /* Pin guest memory */
         guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
                                     PAGE_SIZE, &n, 0);
         if (IS_ERR(guest_page))
                 return PTR_ERR(guest_page);
 
         /* allocate memory for header and transport buffer */
         ret = -ENOMEM;
         hdr = kzalloc(params.hdr_len, GFP_KERNEL_ACCOUNT);
         if (!hdr)
                 goto e_unpin;
 
         trans_data = kzalloc(params.trans_len, GFP_KERNEL_ACCOUNT);
         if (!trans_data)
                 goto e_free_hdr;
 
         memset(&data, 0, sizeof(data));
         data.hdr_address = __psp_pa(hdr);
         data.hdr_len = params.hdr_len;
         data.trans_address = __psp_pa(trans_data);
         data.trans_len = params.trans_len;
 
         /* The SEND_UPDATE_DATA command requires C-bit to be always set. */
         data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
         data.guest_address |= sev_me_mask;
         data.guest_len = params.guest_len;
         data.handle = sev->handle;
 
         ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
 
         if (ret)
                 goto e_free_trans_data;
 
         /* copy transport buffer to user space */
         if (copy_to_user(u64_to_user_ptr(params.trans_uaddr),
                          trans_data, params.trans_len)) {
                 ret = -EFAULT;
                 goto e_free_trans_data;
         }
 
         /* Copy packet header to userspace. */
         if (copy_to_user(u64_to_user_ptr(params.hdr_uaddr), hdr,
                          params.hdr_len))
                 ret = -EFAULT;
 
 e_free_trans_data:
         kfree(trans_data);
 e_free_hdr:
         kfree(hdr);
 e_unpin:
         sev_unpin_memory(kvm, guest_page, n);
 
         return ret;
 }
 
 static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_send_finish data;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         data.handle = sev->handle;
         return sev_issue_cmd(kvm, SEV_CMD_SEND_FINISH, &data, &argp->error);
 }
 
 static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_send_cancel data;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         data.handle = sev->handle;
         return sev_issue_cmd(kvm, SEV_CMD_SEND_CANCEL, &data, &argp->error);
 }
 
 static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_receive_start start;
         struct kvm_sev_receive_start params;
         int *error = &argp->error;
         void *session_data;
         void *pdh_data;
         int ret;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         /* Get parameter from the userspace */
         if (copy_from_user(&params, u64_to_user_ptr(argp->data),
                         sizeof(struct kvm_sev_receive_start)))
                 return -EFAULT;
 
         /* some sanity checks */
         if (!params.pdh_uaddr || !params.pdh_len ||
             !params.session_uaddr || !params.session_len)
                 return -EINVAL;
 
         pdh_data = psp_copy_user_blob(params.pdh_uaddr, params.pdh_len);
         if (IS_ERR(pdh_data))
                 return PTR_ERR(pdh_data);
 
         session_data = psp_copy_user_blob(params.session_uaddr,
                         params.session_len);
         if (IS_ERR(session_data)) {
                 ret = PTR_ERR(session_data);
                 goto e_free_pdh;
         }
 
         memset(&start, 0, sizeof(start));
         start.handle = params.handle;
         start.policy = params.policy;
         start.pdh_cert_address = __psp_pa(pdh_data);
         start.pdh_cert_len = params.pdh_len;
         start.session_address = __psp_pa(session_data);
         start.session_len = params.session_len;
 
         /* create memory encryption context */
         ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_RECEIVE_START, &start,
                                 error);
         if (ret)
                 goto e_free_session;
 
         /* Bind ASID to this guest */
         ret = sev_bind_asid(kvm, start.handle, error);
         if (ret) {
                 sev_decommission(start.handle);
                 goto e_free_session;
         }
 
         params.handle = start.handle;
         if (copy_to_user(u64_to_user_ptr(argp->data),
                          &params, sizeof(struct kvm_sev_receive_start))) {
                 ret = -EFAULT;
                 sev_unbind_asid(kvm, start.handle);
                 goto e_free_session;
         }
 
         sev->handle = start.handle;
         sev->fd = argp->sev_fd;
 
 e_free_session:
         kfree(session_data);
 e_free_pdh:
         kfree(pdh_data);
 
         return ret;
 }
 
 static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct kvm_sev_receive_update_data params;
         struct sev_data_receive_update_data data;
         void *hdr = NULL, *trans = NULL;
         struct page **guest_page;
         unsigned long n;
         int ret, offset;
 
         if (!sev_guest(kvm))
                 return -EINVAL;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data),
                         sizeof(struct kvm_sev_receive_update_data)))
                 return -EFAULT;
 
         if (!params.hdr_uaddr || !params.hdr_len ||
             !params.guest_uaddr || !params.guest_len ||
             !params.trans_uaddr || !params.trans_len)
                 return -EINVAL;
 
         /* Check if we are crossing the page boundary */
         offset = params.guest_uaddr & (PAGE_SIZE - 1);
         if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
                 return -EINVAL;
 
         hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
         if (IS_ERR(hdr))
                 return PTR_ERR(hdr);
 
         trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
         if (IS_ERR(trans)) {
                 ret = PTR_ERR(trans);
                 goto e_free_hdr;
         }
 
         memset(&data, 0, sizeof(data));
         data.hdr_address = __psp_pa(hdr);
         data.hdr_len = params.hdr_len;
         data.trans_address = __psp_pa(trans);
         data.trans_len = params.trans_len;
 
         /* Pin guest memory */
         guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
                                     PAGE_SIZE, &n, 1);
         if (IS_ERR(guest_page)) {
                 ret = PTR_ERR(guest_page);
                 goto e_free_trans;
         }
 
         /*
          * Flush (on non-coherent CPUs) before RECEIVE_UPDATE_DATA, the PSP
          * encrypts the written data with the guest's key, and the cache may
          * contain dirty, unencrypted data.
          */
         sev_clflush_pages(guest_page, n);
 
         /* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */
         data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
         data.guest_address |= sev_me_mask;
         data.guest_len = params.guest_len;
         data.handle = sev->handle;
 
         ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, &data,
                                 &argp->error);
 
         sev_unpin_memory(kvm, guest_page, n);
 
 e_free_trans:
         kfree(trans);
 e_free_hdr:
         kfree(hdr);
 
         return ret;
 }
 
 static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_receive_finish data;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         data.handle = sev->handle;
         return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error);
 }
 
 static bool is_cmd_allowed_from_mirror(u32 cmd_id)
 {
         /*
          * Allow mirrors VM to call KVM_SEV_LAUNCH_UPDATE_VMSA to enable SEV-ES
          * active mirror VMs. Also allow the debugging and status commands.
          */
         if (cmd_id == KVM_SEV_LAUNCH_UPDATE_VMSA ||
             cmd_id == KVM_SEV_GUEST_STATUS || cmd_id == KVM_SEV_DBG_DECRYPT ||
             cmd_id == KVM_SEV_DBG_ENCRYPT)
                 return true;
 
         return false;
 }
 
 static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
 {
         struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
         struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
         int r = -EBUSY;
 
         if (dst_kvm == src_kvm)
                 return -EINVAL;
 
         /*
          * Bail if these VMs are already involved in a migration to avoid
          * deadlock between two VMs trying to migrate to/from each other.
          */
         if (atomic_cmpxchg_acquire(&dst_sev->migration_in_progress, 0, 1))
                 return -EBUSY;
 
         if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
                 goto release_dst;
 
         r = -EINTR;
         if (mutex_lock_killable(&dst_kvm->lock))
                 goto release_src;
         if (mutex_lock_killable_nested(&src_kvm->lock, SINGLE_DEPTH_NESTING))
                 goto unlock_dst;
         return 0;
 
 unlock_dst:
         mutex_unlock(&dst_kvm->lock);
 release_src:
         atomic_set_release(&src_sev->migration_in_progress, 0);
 release_dst:
         atomic_set_release(&dst_sev->migration_in_progress, 0);
         return r;
 }
 
 static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
 {
         struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
         struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
 
         mutex_unlock(&dst_kvm->lock);
         mutex_unlock(&src_kvm->lock);
         atomic_set_release(&dst_sev->migration_in_progress, 0);
         atomic_set_release(&src_sev->migration_in_progress, 0);
 }
 
 /* vCPU mutex subclasses.  */
 enum sev_migration_role {
         SEV_MIGRATION_SOURCE = 0,
         SEV_MIGRATION_TARGET,
         SEV_NR_MIGRATION_ROLES,
 };
 
 static int sev_lock_vcpus_for_migration(struct kvm *kvm,
                                         enum sev_migration_role role)
 {
         struct kvm_vcpu *vcpu;
         unsigned long i, j;
 
         kvm_for_each_vcpu(i, vcpu, kvm) {
                 if (mutex_lock_killable_nested(&vcpu->mutex, role))
                         goto out_unlock;
 
 #ifdef CONFIG_PROVE_LOCKING
                 if (!i)
                         /*
                          * Reset the role to one that avoids colliding with
                          * the role used for the first vcpu mutex.
                          */
                         role = SEV_NR_MIGRATION_ROLES;
                 else
                         mutex_release(&vcpu->mutex.dep_map, _THIS_IP_);
 #endif
         }
 
         return 0;
 
 out_unlock:
 
         kvm_for_each_vcpu(j, vcpu, kvm) {
                 if (i == j)
                         break;
 
 #ifdef CONFIG_PROVE_LOCKING
                 if (j)
                         mutex_acquire(&vcpu->mutex.dep_map, role, 0, _THIS_IP_);
 #endif
 
                 mutex_unlock(&vcpu->mutex);
         }
         return -EINTR;
 }
 
 static void sev_unlock_vcpus_for_migration(struct kvm *kvm)
 {
         struct kvm_vcpu *vcpu;
         unsigned long i;
         bool first = true;
 
         kvm_for_each_vcpu(i, vcpu, kvm) {
                 if (first)
                         first = false;
                 else
                         mutex_acquire(&vcpu->mutex.dep_map,
                                       SEV_NR_MIGRATION_ROLES, 0, _THIS_IP_);
 
                 mutex_unlock(&vcpu->mutex);
         }
 }
 
 static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm)
 {
         struct kvm_sev_info *dst = &to_kvm_svm(dst_kvm)->sev_info;
         struct kvm_sev_info *src = &to_kvm_svm(src_kvm)->sev_info;
         struct kvm_vcpu *dst_vcpu, *src_vcpu;
         struct vcpu_svm *dst_svm, *src_svm;
         struct kvm_sev_info *mirror;
         unsigned long i;
 
         dst->active = true;
         dst->asid = src->asid;
         dst->handle = src->handle;
         dst->pages_locked = src->pages_locked;
         dst->enc_context_owner = src->enc_context_owner;
         dst->es_active = src->es_active;
         dst->vmsa_features = src->vmsa_features;
 
         src->asid = 0;
         src->active = false;
         src->handle = 0;
         src->pages_locked = 0;
         src->enc_context_owner = NULL;
         src->es_active = false;
 
         list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list);
 
         /*
          * If this VM has mirrors, "transfer" each mirror's refcount of the
          * source to the destination (this KVM).  The caller holds a reference
          * to the source, so there's no danger of use-after-free.
          */
         list_cut_before(&dst->mirror_vms, &src->mirror_vms, &src->mirror_vms);
         list_for_each_entry(mirror, &dst->mirror_vms, mirror_entry) {
                 kvm_get_kvm(dst_kvm);
                 kvm_put_kvm(src_kvm);
                 mirror->enc_context_owner = dst_kvm;
         }
 
         /*
          * If this VM is a mirror, remove the old mirror from the owners list
          * and add the new mirror to the list.
          */
         if (is_mirroring_enc_context(dst_kvm)) {
                 struct kvm_sev_info *owner_sev_info =
                         &to_kvm_svm(dst->enc_context_owner)->sev_info;
 
                 list_del(&src->mirror_entry);
                 list_add_tail(&dst->mirror_entry, &owner_sev_info->mirror_vms);
         }
 
         kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) {
                 dst_svm = to_svm(dst_vcpu);
 
                 sev_init_vmcb(dst_svm);
 
                 if (!dst->es_active)
                         continue;
 
                 /*
                  * Note, the source is not required to have the same number of
                  * vCPUs as the destination when migrating a vanilla SEV VM.
                  */
                 src_vcpu = kvm_get_vcpu(src_kvm, i);
                 src_svm = to_svm(src_vcpu);
 
                 /*
                  * Transfer VMSA and GHCB state to the destination.  Nullify and
                  * clear source fields as appropriate, the state now belongs to
                  * the destination.
                  */
                 memcpy(&dst_svm->sev_es, &src_svm->sev_es, sizeof(src_svm->sev_es));
                 dst_svm->vmcb->control.ghcb_gpa = src_svm->vmcb->control.ghcb_gpa;
                 dst_svm->vmcb->control.vmsa_pa = src_svm->vmcb->control.vmsa_pa;
                 dst_vcpu->arch.guest_state_protected = true;
 
                 memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));
                 src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;
                 src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;
                 src_vcpu->arch.guest_state_protected = false;
         }
 }
 
 static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src)
 {
         struct kvm_vcpu *src_vcpu;
         unsigned long i;
 
         if (!sev_es_guest(src))
                 return 0;
 
         if (atomic_read(&src->online_vcpus) != atomic_read(&dst->online_vcpus))
                 return -EINVAL;
 
         kvm_for_each_vcpu(i, src_vcpu, src) {
                 if (!src_vcpu->arch.guest_state_protected)
                         return -EINVAL;
         }
 
         return 0;
 }
 
 int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 {
         struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;
         struct kvm_sev_info *src_sev, *cg_cleanup_sev;
         struct fd f = fdget(source_fd);
         struct kvm *source_kvm;
         bool charged = false;
         int ret;
 
         if (!f.file)
                 return -EBADF;
 
         if (!file_is_kvm(f.file)) {
                 ret = -EBADF;
                 goto out_fput;
         }
 
         source_kvm = f.file->private_data;
         ret = sev_lock_two_vms(kvm, source_kvm);
         if (ret)
                 goto out_fput;
 
         if (kvm->arch.vm_type != source_kvm->arch.vm_type ||
             sev_guest(kvm) || !sev_guest(source_kvm)) {
                 ret = -EINVAL;
                 goto out_unlock;
         }
 
         src_sev = &to_kvm_svm(source_kvm)->sev_info;
 
         dst_sev->misc_cg = get_current_misc_cg();
         cg_cleanup_sev = dst_sev;
         if (dst_sev->misc_cg != src_sev->misc_cg) {
                 ret = sev_misc_cg_try_charge(dst_sev);
                 if (ret)
                         goto out_dst_cgroup;
                 charged = true;
         }
 
         ret = sev_lock_vcpus_for_migration(kvm, SEV_MIGRATION_SOURCE);
         if (ret)
                 goto out_dst_cgroup;
         ret = sev_lock_vcpus_for_migration(source_kvm, SEV_MIGRATION_TARGET);
         if (ret)
                 goto out_dst_vcpu;
 
         ret = sev_check_source_vcpus(kvm, source_kvm);
         if (ret)
                 goto out_source_vcpu;
 
         sev_migrate_from(kvm, source_kvm);
         kvm_vm_dead(source_kvm);
         cg_cleanup_sev = src_sev;
         ret = 0;
 
 out_source_vcpu:
         sev_unlock_vcpus_for_migration(source_kvm);
 out_dst_vcpu:
         sev_unlock_vcpus_for_migration(kvm);
 out_dst_cgroup:
         /* Operates on the source on success, on the destination on failure.  */
         if (charged)
                 sev_misc_cg_uncharge(cg_cleanup_sev);
         put_misc_cg(cg_cleanup_sev->misc_cg);
         cg_cleanup_sev->misc_cg = NULL;
 out_unlock:
         sev_unlock_two_vms(kvm, source_kvm);
 out_fput:
         fdput(f);
         return ret;
 }
 
 int sev_dev_get_attr(u32 group, u64 attr, u64 *val)
 {
         if (group != KVM_X86_GRP_SEV)
                 return -ENXIO;
 
         switch (attr) {
         case KVM_X86_SEV_VMSA_FEATURES:
                 *val = sev_supported_vmsa_features;
                 return 0;
 
         default:
                 return -ENXIO;
         }
 }
 
 /*
  * The guest context contains all the information, keys and metadata
  * associated with the guest that the firmware tracks to implement SEV
  * and SNP features. The firmware stores the guest context in hypervisor
  * provide page via the SNP_GCTX_CREATE command.
  */
 static void *snp_context_create(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct sev_data_snp_addr data = {};
         void *context;
         int rc;
 
         /* Allocate memory for context page */
         context = snp_alloc_firmware_page(GFP_KERNEL_ACCOUNT);
         if (!context)
                 return NULL;
 
         data.address = __psp_pa(context);
         rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_GCTX_CREATE, &data, &argp->error);
         if (rc) {
                 pr_warn("Failed to create SEV-SNP context, rc %d fw_error %d",
                         rc, argp->error);
                 snp_free_firmware_page(context);
                 return NULL;
         }
 
         return context;
 }
 
 static int snp_bind_asid(struct kvm *kvm, int *error)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_snp_activate data = {0};
 
         data.gctx_paddr = __psp_pa(sev->snp_context);
         data.asid = sev_get_asid(kvm);
         return sev_issue_cmd(kvm, SEV_CMD_SNP_ACTIVATE, &data, error);
 }
 
 static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_snp_launch_start start = {0};
         struct kvm_sev_snp_launch_start params;
         int rc;
 
         if (!sev_snp_guest(kvm))
                 return -ENOTTY;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         /* Don't allow userspace to allocate memory for more than 1 SNP context. */
         if (sev->snp_context)
                 return -EINVAL;
 
         sev->snp_context = snp_context_create(kvm, argp);
         if (!sev->snp_context)
                 return -ENOTTY;
 
         if (params.flags)
                 return -EINVAL;
 
         if (params.policy & ~SNP_POLICY_MASK_VALID)
                 return -EINVAL;
 
         /* Check for policy bits that must be set */
         if (!(params.policy & SNP_POLICY_MASK_RSVD_MBO) ||
             !(params.policy & SNP_POLICY_MASK_SMT))
                 return -EINVAL;
 
         if (params.policy & SNP_POLICY_MASK_SINGLE_SOCKET)
                 return -EINVAL;
 
         start.gctx_paddr = __psp_pa(sev->snp_context);
         start.policy = params.policy;
         memcpy(start.gosvw, params.gosvw, sizeof(params.gosvw));
         rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_START, &start, &argp->error);
         if (rc) {
                 pr_debug("%s: SEV_CMD_SNP_LAUNCH_START firmware command failed, rc %d\n",
                          __func__, rc);
                 goto e_free_context;
         }
 
         sev->fd = argp->sev_fd;
         rc = snp_bind_asid(kvm, &argp->error);
         if (rc) {
                 pr_debug("%s: Failed to bind ASID to SEV-SNP context, rc %d\n",
                          __func__, rc);
                 goto e_free_context;
         }
 
         return 0;
 
 e_free_context:
         snp_decommission_context(kvm);
 
         return rc;
 }
 
 struct sev_gmem_populate_args {
         __u8 type;
         int sev_fd;
         int fw_error;
 };
 
 static int sev_gmem_post_populate(struct kvm *kvm, gfn_t gfn_start, kvm_pfn_t pfn,
                                   void __user *src, int order, void *opaque)
 {
         struct sev_gmem_populate_args *sev_populate_args = opaque;
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         int n_private = 0, ret, i;
         int npages = (1 << order);
         gfn_t gfn;
 
         if (WARN_ON_ONCE(sev_populate_args->type != KVM_SEV_SNP_PAGE_TYPE_ZERO && !src))
                 return -EINVAL;
 
         for (gfn = gfn_start, i = 0; gfn < gfn_start + npages; gfn++, i++) {
                 struct sev_data_snp_launch_update fw_args = {0};
                 bool assigned;
                 int level;
 
                 ret = snp_lookup_rmpentry((u64)pfn + i, &assigned, &level);
                 if (ret || assigned) {
                         pr_debug("%s: Failed to ensure GFN 0x%llx RMP entry is initial shared state, ret: %d assigned: %d\n",
                                  __func__, gfn, ret, assigned);
                         ret = ret ? -EINVAL : -EEXIST;
                         goto err;
                 }
 
                 if (src) {
                         void *vaddr = kmap_local_pfn(pfn + i);
 
                         ret = copy_from_user(vaddr, src + i * PAGE_SIZE, PAGE_SIZE);
                         if (ret)
                                 goto err;
                         kunmap_local(vaddr);
                 }
 
                 ret = rmp_make_private(pfn + i, gfn << PAGE_SHIFT, PG_LEVEL_4K,
                                        sev_get_asid(kvm), true);
                 if (ret)
                         goto err;
 
                 n_private++;
 
                 fw_args.gctx_paddr = __psp_pa(sev->snp_context);
                 fw_args.address = __sme_set(pfn_to_hpa(pfn + i));
                 fw_args.page_size = PG_LEVEL_TO_RMP(PG_LEVEL_4K);
                 fw_args.page_type = sev_populate_args->type;
 
                 ret = __sev_issue_cmd(sev_populate_args->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE,
                                       &fw_args, &sev_populate_args->fw_error);
                 if (ret)
                         goto fw_err;
         }
 
         return 0;
 
 fw_err:
         /*
          * If the firmware command failed handle the reclaim and cleanup of that
          * PFN specially vs. prior pages which can be cleaned up below without
          * needing to reclaim in advance.
          *
          * Additionally, when invalid CPUID function entries are detected,
          * firmware writes the expected values into the page and leaves it
          * unencrypted so it can be used for debugging and error-reporting.
          *
          * Copy this page back into the source buffer so userspace can use this
          * information to provide information on which CPUID leaves/fields
          * failed CPUID validation.
          */
         if (!snp_page_reclaim(kvm, pfn + i) &&
             sev_populate_args->type == KVM_SEV_SNP_PAGE_TYPE_CPUID &&
             sev_populate_args->fw_error == SEV_RET_INVALID_PARAM) {
                 void *vaddr = kmap_local_pfn(pfn + i);
 
                 if (copy_to_user(src + i * PAGE_SIZE, vaddr, PAGE_SIZE))
                         pr_debug("Failed to write CPUID page back to userspace\n");
 
                 kunmap_local(vaddr);
         }
 
         /* pfn + i is hypervisor-owned now, so skip below cleanup for it. */
         n_private--;
 
 err:
         pr_debug("%s: exiting with error ret %d (fw_error %d), restoring %d gmem PFNs to shared.\n",
                  __func__, ret, sev_populate_args->fw_error, n_private);
         for (i = 0; i < n_private; i++)
                 kvm_rmp_make_shared(kvm, pfn + i, PG_LEVEL_4K);
 
         return ret;
 }
 
 static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_gmem_populate_args sev_populate_args = {0};
         struct kvm_sev_snp_launch_update params;
         struct kvm_memory_slot *memslot;
         long npages, count;
         void __user *src;
         int ret = 0;
 
         if (!sev_snp_guest(kvm) || !sev->snp_context)
                 return -EINVAL;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         pr_debug("%s: GFN start 0x%llx length 0x%llx type %d flags %d\n", __func__,
                  params.gfn_start, params.len, params.type, params.flags);
 
         if (!PAGE_ALIGNED(params.len) || params.flags ||
             (params.type != KVM_SEV_SNP_PAGE_TYPE_NORMAL &&
              params.type != KVM_SEV_SNP_PAGE_TYPE_ZERO &&
              params.type != KVM_SEV_SNP_PAGE_TYPE_UNMEASURED &&
              params.type != KVM_SEV_SNP_PAGE_TYPE_SECRETS &&
              params.type != KVM_SEV_SNP_PAGE_TYPE_CPUID))
                 return -EINVAL;
 
         npages = params.len / PAGE_SIZE;
 
         /*
          * For each GFN that's being prepared as part of the initial guest
          * state, the following pre-conditions are verified:
          *
          *   1) The backing memslot is a valid private memslot.
          *   2) The GFN has been set to private via KVM_SET_MEMORY_ATTRIBUTES
          *      beforehand.
          *   3) The PFN of the guest_memfd has not already been set to private
          *      in the RMP table.
          *
          * The KVM MMU relies on kvm->mmu_invalidate_seq to retry nested page
          * faults if there's a race between a fault and an attribute update via
          * KVM_SET_MEMORY_ATTRIBUTES, and a similar approach could be utilized
          * here. However, kvm->slots_lock guards against both this as well as
          * concurrent memslot updates occurring while these checks are being
          * performed, so use that here to make it easier to reason about the
          * initial expected state and better guard against unexpected
          * situations.
          */
         mutex_lock(&kvm->slots_lock);
 
         memslot = gfn_to_memslot(kvm, params.gfn_start);
         if (!kvm_slot_can_be_private(memslot)) {
                 ret = -EINVAL;
                 goto out;
         }
 
         sev_populate_args.sev_fd = argp->sev_fd;
         sev_populate_args.type = params.type;
         src = params.type == KVM_SEV_SNP_PAGE_TYPE_ZERO ? NULL : u64_to_user_ptr(params.uaddr);
 
         count = kvm_gmem_populate(kvm, params.gfn_start, src, npages,
                                   sev_gmem_post_populate, &sev_populate_args);
         if (count < 0) {
                 argp->error = sev_populate_args.fw_error;
                 pr_debug("%s: kvm_gmem_populate failed, ret %ld (fw_error %d)\n",
                          __func__, count, argp->error);
                 ret = -EIO;
         } else {
                 params.gfn_start += count;
                 params.len -= count * PAGE_SIZE;
                 if (params.type != KVM_SEV_SNP_PAGE_TYPE_ZERO)
                         params.uaddr += count * PAGE_SIZE;
 
                 ret = 0;
                 if (copy_to_user(u64_to_user_ptr(argp->data), &params, sizeof(params)))
                         ret = -EFAULT;
         }
 
 out:
         mutex_unlock(&kvm->slots_lock);
 
         return ret;
 }
 
 static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_snp_launch_update data = {};
         struct kvm_vcpu *vcpu;
         unsigned long i;
         int ret;
 
         data.gctx_paddr = __psp_pa(sev->snp_context);
         data.page_type = SNP_PAGE_TYPE_VMSA;
 
         kvm_for_each_vcpu(i, vcpu, kvm) {
                 struct vcpu_svm *svm = to_svm(vcpu);
                 u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT;
 
                 ret = sev_es_sync_vmsa(svm);
                 if (ret)
                         return ret;
 
                 /* Transition the VMSA page to a firmware state. */
                 ret = rmp_make_private(pfn, INITIAL_VMSA_GPA, PG_LEVEL_4K, sev->asid, true);
                 if (ret)
                         return ret;
 
                 /* Issue the SNP command to encrypt the VMSA */
                 data.address = __sme_pa(svm->sev_es.vmsa);
                 ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE,
                                       &data, &argp->error);
                 if (ret) {
                         snp_page_reclaim(kvm, pfn);
 
                         return ret;
                 }
 
                 svm->vcpu.arch.guest_state_protected = true;
                 /*
                  * SEV-ES (and thus SNP) guest mandates LBR Virtualization to
                  * be _always_ ON. Enable it only after setting
                  * guest_state_protected because KVM_SET_MSRS allows dynamic
                  * toggling of LBRV (for performance reason) on write access to
                  * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.
                  */
                 svm_enable_lbrv(vcpu);
         }
 
         return 0;
 }
 
 static int snp_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct kvm_sev_snp_launch_finish params;
         struct sev_data_snp_launch_finish *data;
         void *id_block = NULL, *id_auth = NULL;
         int ret;
 
         if (!sev_snp_guest(kvm))
                 return -ENOTTY;
 
         if (!sev->snp_context)
                 return -EINVAL;
 
         if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))
                 return -EFAULT;
 
         if (params.flags)
                 return -EINVAL;
 
         /* Measure all vCPUs using LAUNCH_UPDATE before finalizing the launch flow. */
         ret = snp_launch_update_vmsa(kvm, argp);
         if (ret)
                 return ret;
 
         data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
         if (!data)
                 return -ENOMEM;
 
         if (params.id_block_en) {
                 id_block = psp_copy_user_blob(params.id_block_uaddr, KVM_SEV_SNP_ID_BLOCK_SIZE);
                 if (IS_ERR(id_block)) {
                         ret = PTR_ERR(id_block);
                         goto e_free;
                 }
 
                 data->id_block_en = 1;
                 data->id_block_paddr = __sme_pa(id_block);
 
                 id_auth = psp_copy_user_blob(params.id_auth_uaddr, KVM_SEV_SNP_ID_AUTH_SIZE);
                 if (IS_ERR(id_auth)) {
                         ret = PTR_ERR(id_auth);
                         goto e_free_id_block;
                 }
 
                 data->id_auth_paddr = __sme_pa(id_auth);
 
                 if (params.auth_key_en)
                         data->auth_key_en = 1;
         }
 
         data->vcek_disabled = params.vcek_disabled;
 
         memcpy(data->host_data, params.host_data, KVM_SEV_SNP_FINISH_DATA_SIZE);
         data->gctx_paddr = __psp_pa(sev->snp_context);
         ret = sev_issue_cmd(kvm, SEV_CMD_SNP_LAUNCH_FINISH, data, &argp->error);
 
         /*
          * Now that there will be no more SNP_LAUNCH_UPDATE ioctls, private pages
          * can be given to the guest simply by marking the RMP entry as private.
          * This can happen on first access and also with KVM_PRE_FAULT_MEMORY.
          */
         if (!ret)
                 kvm->arch.pre_fault_allowed = true;
 
         kfree(id_auth);
 
 e_free_id_block:
         kfree(id_block);
 
 e_free:
         kfree(data);
 
         return ret;
 }
 
 int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
 {
         struct kvm_sev_cmd sev_cmd;
         int r;
 
         if (!sev_enabled)
                 return -ENOTTY;
 
         if (!argp)
                 return 0;
 
         if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
                 return -EFAULT;
 
         mutex_lock(&kvm->lock);
 
         /* Only the enc_context_owner handles some memory enc operations. */
         if (is_mirroring_enc_context(kvm) &&
             !is_cmd_allowed_from_mirror(sev_cmd.id)) {
                 r = -EINVAL;
                 goto out;
         }
 
         /*
          * Once KVM_SEV_INIT2 initializes a KVM instance as an SNP guest, only
          * allow the use of SNP-specific commands.
          */
         if (sev_snp_guest(kvm) && sev_cmd.id < KVM_SEV_SNP_LAUNCH_START) {
                 r = -EPERM;
                 goto out;
         }
 
         switch (sev_cmd.id) {
         case KVM_SEV_ES_INIT:
                 if (!sev_es_enabled) {
                         r = -ENOTTY;
                         goto out;
                 }
                 fallthrough;
         case KVM_SEV_INIT:
                 r = sev_guest_init(kvm, &sev_cmd);
                 break;
         case KVM_SEV_INIT2:
                 r = sev_guest_init2(kvm, &sev_cmd);
                 break;
         case KVM_SEV_LAUNCH_START:
                 r = sev_launch_start(kvm, &sev_cmd);
                 break;
         case KVM_SEV_LAUNCH_UPDATE_DATA:
                 r = sev_launch_update_data(kvm, &sev_cmd);
                 break;
         case KVM_SEV_LAUNCH_UPDATE_VMSA:
                 r = sev_launch_update_vmsa(kvm, &sev_cmd);
                 break;
         case KVM_SEV_LAUNCH_MEASURE:
                 r = sev_launch_measure(kvm, &sev_cmd);
                 break;
         case KVM_SEV_LAUNCH_FINISH:
                 r = sev_launch_finish(kvm, &sev_cmd);
                 break;
         case KVM_SEV_GUEST_STATUS:
                 r = sev_guest_status(kvm, &sev_cmd);
                 break;
         case KVM_SEV_DBG_DECRYPT:
                 r = sev_dbg_crypt(kvm, &sev_cmd, true);
                 break;
         case KVM_SEV_DBG_ENCRYPT:
                 r = sev_dbg_crypt(kvm, &sev_cmd, false);
                 break;
         case KVM_SEV_LAUNCH_SECRET:
                 r = sev_launch_secret(kvm, &sev_cmd);
                 break;
         case KVM_SEV_GET_ATTESTATION_REPORT:
                 r = sev_get_attestation_report(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SEND_START:
                 r = sev_send_start(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SEND_UPDATE_DATA:
                 r = sev_send_update_data(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SEND_FINISH:
                 r = sev_send_finish(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SEND_CANCEL:
                 r = sev_send_cancel(kvm, &sev_cmd);
                 break;
         case KVM_SEV_RECEIVE_START:
                 r = sev_receive_start(kvm, &sev_cmd);
                 break;
         case KVM_SEV_RECEIVE_UPDATE_DATA:
                 r = sev_receive_update_data(kvm, &sev_cmd);
                 break;
         case KVM_SEV_RECEIVE_FINISH:
                 r = sev_receive_finish(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SNP_LAUNCH_START:
                 r = snp_launch_start(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SNP_LAUNCH_UPDATE:
                 r = snp_launch_update(kvm, &sev_cmd);
                 break;
         case KVM_SEV_SNP_LAUNCH_FINISH:
                 r = snp_launch_finish(kvm, &sev_cmd);
                 break;
         default:
                 r = -EINVAL;
                 goto out;
         }
 
         if (copy_to_user(argp, &sev_cmd, sizeof(struct kvm_sev_cmd)))
                 r = -EFAULT;
 
 out:
         mutex_unlock(&kvm->lock);
         return r;
 }
 
 int sev_mem_enc_register_region(struct kvm *kvm,
                                 struct kvm_enc_region *range)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct enc_region *region;
         int ret = 0;
 
         if (!sev_guest(kvm))
                 return -ENOTTY;
 
         /* If kvm is mirroring encryption context it isn't responsible for it */
         if (is_mirroring_enc_context(kvm))
                 return -EINVAL;
 
         if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
                 return -EINVAL;
 
         region = kzalloc(sizeof(*region), GFP_KERNEL_ACCOUNT);
         if (!region)
                 return -ENOMEM;
 
         mutex_lock(&kvm->lock);
         region->pages = sev_pin_memory(kvm, range->addr, range->size, &region->npages, 1);
         if (IS_ERR(region->pages)) {
                 ret = PTR_ERR(region->pages);
                 mutex_unlock(&kvm->lock);
                 goto e_free;
         }
 
         /*
          * The guest may change the memory encryption attribute from C=0 -> C=1
          * or vice versa for this memory range. Lets make sure caches are
          * flushed to ensure that guest data gets written into memory with
          * correct C-bit.  Note, this must be done before dropping kvm->lock,
          * as region and its array of pages can be freed by a different task
          * once kvm->lock is released.
          */
         sev_clflush_pages(region->pages, region->npages);
 
         region->uaddr = range->addr;
         region->size = range->size;
 
         list_add_tail(&region->list, &sev->regions_list);
         mutex_unlock(&kvm->lock);
 
         return ret;
 
 e_free:
         kfree(region);
         return ret;
 }
 
 static struct enc_region *
 find_enc_region(struct kvm *kvm, struct kvm_enc_region *range)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct list_head *head = &sev->regions_list;
         struct enc_region *i;
 
         list_for_each_entry(i, head, list) {
                 if (i->uaddr == range->addr &&
                     i->size == range->size)
                         return i;
         }
 
         return NULL;
 }
 
 static void __unregister_enc_region_locked(struct kvm *kvm,
                                            struct enc_region *region)
 {
         sev_unpin_memory(kvm, region->pages, region->npages);
         list_del(&region->list);
         kfree(region);
 }
 
 int sev_mem_enc_unregister_region(struct kvm *kvm,
                                   struct kvm_enc_region *range)
 {
         struct enc_region *region;
         int ret;
 
         /* If kvm is mirroring encryption context it isn't responsible for it */
         if (is_mirroring_enc_context(kvm))
                 return -EINVAL;
 
         mutex_lock(&kvm->lock);
 
         if (!sev_guest(kvm)) {
                 ret = -ENOTTY;
                 goto failed;
         }
 
         region = find_enc_region(kvm, range);
         if (!region) {
                 ret = -EINVAL;
                 goto failed;
         }
 
         /*
          * Ensure that all guest tagged cache entries are flushed before
          * releasing the pages back to the system for use. CLFLUSH will
          * not do this, so issue a WBINVD.
          */
         wbinvd_on_all_cpus();
 
         __unregister_enc_region_locked(kvm, region);
 
         mutex_unlock(&kvm->lock);
         return 0;
 
 failed:
         mutex_unlock(&kvm->lock);
         return ret;
 }
 
 int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 {
         struct fd f = fdget(source_fd);
         struct kvm *source_kvm;
         struct kvm_sev_info *source_sev, *mirror_sev;
         int ret;
 
         if (!f.file)
                 return -EBADF;
 
         if (!file_is_kvm(f.file)) {
                 ret = -EBADF;
                 goto e_source_fput;
         }
 
         source_kvm = f.file->private_data;
         ret = sev_lock_two_vms(kvm, source_kvm);
         if (ret)
                 goto e_source_fput;
 
         /*
          * Mirrors of mirrors should work, but let's not get silly.  Also
          * disallow out-of-band SEV/SEV-ES init if the target is already an
          * SEV guest, or if vCPUs have been created.  KVM relies on vCPUs being
          * created after SEV/SEV-ES initialization, e.g. to init intercepts.
          */
         if (sev_guest(kvm) || !sev_guest(source_kvm) ||
             is_mirroring_enc_context(source_kvm) || kvm->created_vcpus) {
                 ret = -EINVAL;
                 goto e_unlock;
         }
 
         /*
          * The mirror kvm holds an enc_context_owner ref so its asid can't
          * disappear until we're done with it
          */
         source_sev = &to_kvm_svm(source_kvm)->sev_info;
         kvm_get_kvm(source_kvm);
         mirror_sev = &to_kvm_svm(kvm)->sev_info;
         list_add_tail(&mirror_sev->mirror_entry, &source_sev->mirror_vms);
 
         /* Set enc_context_owner and copy its encryption context over */
         mirror_sev->enc_context_owner = source_kvm;
         mirror_sev->active = true;
         mirror_sev->asid = source_sev->asid;
         mirror_sev->fd = source_sev->fd;
         mirror_sev->es_active = source_sev->es_active;
         mirror_sev->need_init = false;
         mirror_sev->handle = source_sev->handle;
         INIT_LIST_HEAD(&mirror_sev->regions_list);
         INIT_LIST_HEAD(&mirror_sev->mirror_vms);
         ret = 0;
 
         /*
          * Do not copy ap_jump_table. Since the mirror does not share the same
          * KVM contexts as the original, and they may have different
          * memory-views.
          */
 
 e_unlock:
         sev_unlock_two_vms(kvm, source_kvm);
 e_source_fput:
         fdput(f);
         return ret;
 }
 
 static int snp_decommission_context(struct kvm *kvm)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct sev_data_snp_addr data = {};
         int ret;
 
         /* If context is not created then do nothing */
         if (!sev->snp_context)
                 return 0;
 
         /* Do the decommision, which will unbind the ASID from the SNP context */
         data.address = __sme_pa(sev->snp_context);
         down_write(&sev_deactivate_lock);
         ret = sev_do_cmd(SEV_CMD_SNP_DECOMMISSION, &data, NULL);
         up_write(&sev_deactivate_lock);
 
         if (WARN_ONCE(ret, "Failed to release guest context, ret %d", ret))
                 return ret;
 
         snp_free_firmware_page(sev->snp_context);
         sev->snp_context = NULL;
 
         return 0;
 }
 
 void sev_vm_destroy(struct kvm *kvm)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         struct list_head *head = &sev->regions_list;
         struct list_head *pos, *q;
 
         if (!sev_guest(kvm))
                 return;
 
         WARN_ON(!list_empty(&sev->mirror_vms));
 
         /* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */
         if (is_mirroring_enc_context(kvm)) {
                 struct kvm *owner_kvm = sev->enc_context_owner;
 
                 mutex_lock(&owner_kvm->lock);
                 list_del(&sev->mirror_entry);
                 mutex_unlock(&owner_kvm->lock);
                 kvm_put_kvm(owner_kvm);
                 return;
         }
 
         /*
          * Ensure that all guest tagged cache entries are flushed before
          * releasing the pages back to the system for use. CLFLUSH will
          * not do this, so issue a WBINVD.
          */
         wbinvd_on_all_cpus();
 
         /*
          * if userspace was terminated before unregistering the memory regions
          * then lets unpin all the registered memory.
          */
         if (!list_empty(head)) {
                 list_for_each_safe(pos, q, head) {
                         __unregister_enc_region_locked(kvm,
                                 list_entry(pos, struct enc_region, list));
                         cond_resched();
                 }
         }
 
         if (sev_snp_guest(kvm)) {
                 snp_guest_req_cleanup(kvm);
 
                 /*
                  * Decomission handles unbinding of the ASID. If it fails for
                  * some unexpected reason, just leak the ASID.
                  */
                 if (snp_decommission_context(kvm))
                         return;
         } else {
                 sev_unbind_asid(kvm, sev->handle);
         }
 
         sev_asid_free(sev);
 }
 
 void __init sev_set_cpu_caps(void)
 {
         if (sev_enabled) {
                 kvm_cpu_cap_set(X86_FEATURE_SEV);
                 kvm_caps.supported_vm_types |= BIT(KVM_X86_SEV_VM);
         }
         if (sev_es_enabled) {
                 kvm_cpu_cap_set(X86_FEATURE_SEV_ES);
                 kvm_caps.supported_vm_types |= BIT(KVM_X86_SEV_ES_VM);
         }
         if (sev_snp_enabled) {
                 kvm_cpu_cap_set(X86_FEATURE_SEV_SNP);
                 kvm_caps.supported_vm_types |= BIT(KVM_X86_SNP_VM);
         }
 }
 
 void __init sev_hardware_setup(void)
 {
         unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
         bool sev_snp_supported = false;
         bool sev_es_supported = false;
         bool sev_supported = false;
 
         if (!sev_enabled || !npt_enabled || !nrips)
                 goto out;
 
         /*
          * SEV must obviously be supported in hardware.  Sanity check that the
          * CPU supports decode assists, which is mandatory for SEV guests to
          * support instruction emulation.  Ditto for flushing by ASID, as SEV
          * guests are bound to a single ASID, i.e. KVM can't rotate to a new
          * ASID to effect a TLB flush.
          */
         if (!boot_cpu_has(X86_FEATURE_SEV) ||
             WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)) ||
             WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_FLUSHBYASID)))
                 goto out;
 
         /* Retrieve SEV CPUID information */
         cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);
 
         /* Set encryption bit location for SEV-ES guests */
         sev_enc_bit = ebx & 0x3f;
 
         /* Maximum number of encrypted guests supported simultaneously */
         max_sev_asid = ecx;
         if (!max_sev_asid)
                 goto out;
 
         /* Minimum ASID value that should be used for SEV guest */
         min_sev_asid = edx;
         sev_me_mask = 1UL << (ebx & 0x3f);
 
         /*
          * Initialize SEV ASID bitmaps. Allocate space for ASID 0 in the bitmap,
          * even though it's never used, so that the bitmap is indexed by the
          * actual ASID.
          */
         nr_asids = max_sev_asid + 1;
         sev_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
         if (!sev_asid_bitmap)
                 goto out;
 
         sev_reclaim_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
         if (!sev_reclaim_asid_bitmap) {
                 bitmap_free(sev_asid_bitmap);
                 sev_asid_bitmap = NULL;
                 goto out;
         }
 
         if (min_sev_asid <= max_sev_asid) {
                 sev_asid_count = max_sev_asid - min_sev_asid + 1;
                 WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count));
         }
         sev_supported = true;
 
         /* SEV-ES support requested? */
         if (!sev_es_enabled)
                 goto out;
 
         /*
          * SEV-ES requires MMIO caching as KVM doesn't have access to the guest
          * instruction stream, i.e. can't emulate in response to a #NPF and
          * instead relies on #NPF(RSVD) being reflected into the guest as #VC
          * (the guest can then do a #VMGEXIT to request MMIO emulation).
          */
         if (!enable_mmio_caching)
                 goto out;
 
         /* Does the CPU support SEV-ES? */
         if (!boot_cpu_has(X86_FEATURE_SEV_ES))
                 goto out;
 
         if (!lbrv) {
                 WARN_ONCE(!boot_cpu_has(X86_FEATURE_LBRV),
                           "LBRV must be present for SEV-ES support");
                 goto out;
         }
 
         /* Has the system been allocated ASIDs for SEV-ES? */
         if (min_sev_asid == 1)
                 goto out;
 
         sev_es_asid_count = min_sev_asid - 1;
         WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count));
         sev_es_supported = true;
         sev_snp_supported = sev_snp_enabled && cc_platform_has(CC_ATTR_HOST_SEV_SNP);
 
 out:
         if (boot_cpu_has(X86_FEATURE_SEV))
                 pr_info("SEV %s (ASIDs %u - %u)\n",
                         sev_supported ? min_sev_asid <= max_sev_asid ? "enabled" :
                                                                        "unusable" :
                                                                        "disabled",
                         min_sev_asid, max_sev_asid);
         if (boot_cpu_has(X86_FEATURE_SEV_ES))
                 pr_info("SEV-ES %s (ASIDs %u - %u)\n",
                         sev_es_supported ? "enabled" : "disabled",
                         min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
         if (boot_cpu_has(X86_FEATURE_SEV_SNP))
                 pr_info("SEV-SNP %s (ASIDs %u - %u)\n",
                         sev_snp_supported ? "enabled" : "disabled",
                         min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
 
         sev_enabled = sev_supported;
         sev_es_enabled = sev_es_supported;
         sev_snp_enabled = sev_snp_supported;
 
         if (!sev_es_enabled || !cpu_feature_enabled(X86_FEATURE_DEBUG_SWAP) ||
             !cpu_feature_enabled(X86_FEATURE_NO_NESTED_DATA_BP))
                 sev_es_debug_swap_enabled = false;
 
         sev_supported_vmsa_features = 0;
         if (sev_es_debug_swap_enabled)
                 sev_supported_vmsa_features |= SVM_SEV_FEAT_DEBUG_SWAP;
 }
 
 void sev_hardware_unsetup(void)
 {
         if (!sev_enabled)
                 return;
 
         /* No need to take sev_bitmap_lock, all VMs have been destroyed. */
         sev_flush_asids(1, max_sev_asid);
 
         bitmap_free(sev_asid_bitmap);
         bitmap_free(sev_reclaim_asid_bitmap);
 
         misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
         misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
 }
 
 int sev_cpu_init(struct svm_cpu_data *sd)
 {
         if (!sev_enabled)
                 return 0;
 
         sd->sev_vmcbs = kcalloc(nr_asids, sizeof(void *), GFP_KERNEL);
         if (!sd->sev_vmcbs)
                 return -ENOMEM;
 
         return 0;
 }
 
 /*
  * Pages used by hardware to hold guest encrypted state must be flushed before
  * returning them to the system.
  */
 static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va)
 {
         unsigned int asid = sev_get_asid(vcpu->kvm);
 
         /*
          * Note!  The address must be a kernel address, as regular page walk
          * checks are performed by VM_PAGE_FLUSH, i.e. operating on a user
          * address is non-deterministic and unsafe.  This function deliberately
          * takes a pointer to deter passing in a user address.
          */
         unsigned long addr = (unsigned long)va;
 
         /*
          * If CPU enforced cache coherency for encrypted mappings of the
          * same physical page is supported, use CLFLUSHOPT instead. NOTE: cache
          * flush is still needed in order to work properly with DMA devices.
          */
         if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) {
                 clflush_cache_range(va, PAGE_SIZE);
                 return;
         }
 
         /*
          * VM Page Flush takes a host virtual address and a guest ASID.  Fall
          * back to WBINVD if this faults so as not to make any problems worse
          * by leaving stale encrypted data in the cache.
          */
         if (WARN_ON_ONCE(wrmsrl_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid)))
                 goto do_wbinvd;
 
         return;
 
 do_wbinvd:
         wbinvd_on_all_cpus();
 }
 
 void sev_guest_memory_reclaimed(struct kvm *kvm)
 {
         /*
          * With SNP+gmem, private/encrypted memory is unreachable via the
          * hva-based mmu notifiers, so these events are only actually
          * pertaining to shared pages where there is no need to perform
          * the WBINVD to flush associated caches.
          */
         if (!sev_guest(kvm) || sev_snp_guest(kvm))
                 return;
 
         wbinvd_on_all_cpus();
 }
 
 void sev_free_vcpu(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm;
 
         if (!sev_es_guest(vcpu->kvm))
                 return;
 
         svm = to_svm(vcpu);
 
         /*
          * If it's an SNP guest, then the VMSA was marked in the RMP table as
          * a guest-owned page. Transition the page to hypervisor state before
          * releasing it back to the system.
          */
         if (sev_snp_guest(vcpu->kvm)) {
                 u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT;
 
                 if (kvm_rmp_make_shared(vcpu->kvm, pfn, PG_LEVEL_4K))
                         goto skip_vmsa_free;
         }
 
         if (vcpu->arch.guest_state_protected)
                 sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa);
 
         __free_page(virt_to_page(svm->sev_es.vmsa));
 
 skip_vmsa_free:
         if (svm->sev_es.ghcb_sa_free)
                 kvfree(svm->sev_es.ghcb_sa);
 }
 
 static void dump_ghcb(struct vcpu_svm *svm)
 {
         struct ghcb *ghcb = svm->sev_es.ghcb;
         unsigned int nbits;
 
         /* Re-use the dump_invalid_vmcb module parameter */
         if (!dump_invalid_vmcb) {
                 pr_warn_ratelimited("set kvm_amd.dump_invalid_vmcb=1 to dump internal KVM state.\n");
                 return;
         }
 
         nbits = sizeof(ghcb->save.valid_bitmap) * 8;
 
         pr_err("GHCB (GPA=%016llx):\n", svm->vmcb->control.ghcb_gpa);
         pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_code",
                ghcb->save.sw_exit_code, ghcb_sw_exit_code_is_valid(ghcb));
         pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_1",
                ghcb->save.sw_exit_info_1, ghcb_sw_exit_info_1_is_valid(ghcb));
         pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_2",
                ghcb->save.sw_exit_info_2, ghcb_sw_exit_info_2_is_valid(ghcb));
         pr_err("%-20s%016llx is_valid: %u\n", "sw_scratch",
                ghcb->save.sw_scratch, ghcb_sw_scratch_is_valid(ghcb));
         pr_err("%-20s%*pb\n", "valid_bitmap", nbits, ghcb->save.valid_bitmap);
 }
 
 static void sev_es_sync_to_ghcb(struct vcpu_svm *svm)
 {
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct ghcb *ghcb = svm->sev_es.ghcb;
 
         /*
          * The GHCB protocol so far allows for the following data
          * to be returned:
          *   GPRs RAX, RBX, RCX, RDX
          *
          * Copy their values, even if they may not have been written during the
          * VM-Exit.  It's the guest's responsibility to not consume random data.
          */
         ghcb_set_rax(ghcb, vcpu->arch.regs[VCPU_REGS_RAX]);
         ghcb_set_rbx(ghcb, vcpu->arch.regs[VCPU_REGS_RBX]);
         ghcb_set_rcx(ghcb, vcpu->arch.regs[VCPU_REGS_RCX]);
         ghcb_set_rdx(ghcb, vcpu->arch.regs[VCPU_REGS_RDX]);
 }
 
 static void sev_es_sync_from_ghcb(struct vcpu_svm *svm)
 {
         struct vmcb_control_area *control = &svm->vmcb->control;
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct ghcb *ghcb = svm->sev_es.ghcb;
         u64 exit_code;
 
         /*
          * The GHCB protocol so far allows for the following data
          * to be supplied:
          *   GPRs RAX, RBX, RCX, RDX
          *   XCR0
          *   CPL
          *
          * VMMCALL allows the guest to provide extra registers. KVM also
          * expects RSI for hypercalls, so include that, too.
          *
          * Copy their values to the appropriate location if supplied.
          */
         memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
 
         BUILD_BUG_ON(sizeof(svm->sev_es.valid_bitmap) != sizeof(ghcb->save.valid_bitmap));
         memcpy(&svm->sev_es.valid_bitmap, &ghcb->save.valid_bitmap, sizeof(ghcb->save.valid_bitmap));
 
         vcpu->arch.regs[VCPU_REGS_RAX] = kvm_ghcb_get_rax_if_valid(svm, ghcb);
         vcpu->arch.regs[VCPU_REGS_RBX] = kvm_ghcb_get_rbx_if_valid(svm, ghcb);
         vcpu->arch.regs[VCPU_REGS_RCX] = kvm_ghcb_get_rcx_if_valid(svm, ghcb);
         vcpu->arch.regs[VCPU_REGS_RDX] = kvm_ghcb_get_rdx_if_valid(svm, ghcb);
         vcpu->arch.regs[VCPU_REGS_RSI] = kvm_ghcb_get_rsi_if_valid(svm, ghcb);
 
         svm->vmcb->save.cpl = kvm_ghcb_get_cpl_if_valid(svm, ghcb);
 
         if (kvm_ghcb_xcr0_is_valid(svm)) {
                 vcpu->arch.xcr0 = ghcb_get_xcr0(ghcb);
                 kvm_update_cpuid_runtime(vcpu);
         }
 
         /* Copy the GHCB exit information into the VMCB fields */
         exit_code = ghcb_get_sw_exit_code(ghcb);
         control->exit_code = lower_32_bits(exit_code);
         control->exit_code_hi = upper_32_bits(exit_code);
         control->exit_info_1 = ghcb_get_sw_exit_info_1(ghcb);
         control->exit_info_2 = ghcb_get_sw_exit_info_2(ghcb);
         svm->sev_es.sw_scratch = kvm_ghcb_get_sw_scratch_if_valid(svm, ghcb);
 
         /* Clear the valid entries fields */
         memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
 }
 
 static u64 kvm_ghcb_get_sw_exit_code(struct vmcb_control_area *control)
 {
         return (((u64)control->exit_code_hi) << 32) | control->exit_code;
 }
 
 static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
 {
         struct vmcb_control_area *control = &svm->vmcb->control;
         struct kvm_vcpu *vcpu = &svm->vcpu;
         u64 exit_code;
         u64 reason;
 
         /*
          * Retrieve the exit code now even though it may not be marked valid
          * as it could help with debugging.
          */
         exit_code = kvm_ghcb_get_sw_exit_code(control);
 
         /* Only GHCB Usage code 0 is supported */
         if (svm->sev_es.ghcb->ghcb_usage) {
                 reason = GHCB_ERR_INVALID_USAGE;
                 goto vmgexit_err;
         }
 
         reason = GHCB_ERR_MISSING_INPUT;
 
         if (!kvm_ghcb_sw_exit_code_is_valid(svm) ||
             !kvm_ghcb_sw_exit_info_1_is_valid(svm) ||
             !kvm_ghcb_sw_exit_info_2_is_valid(svm))
                 goto vmgexit_err;
 
         switch (exit_code) {
         case SVM_EXIT_READ_DR7:
                 break;
         case SVM_EXIT_WRITE_DR7:
                 if (!kvm_ghcb_rax_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_EXIT_RDTSC:
                 break;
         case SVM_EXIT_RDPMC:
                 if (!kvm_ghcb_rcx_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_EXIT_CPUID:
                 if (!kvm_ghcb_rax_is_valid(svm) ||
                     !kvm_ghcb_rcx_is_valid(svm))
                         goto vmgexit_err;
                 if (vcpu->arch.regs[VCPU_REGS_RAX] == 0xd)
                         if (!kvm_ghcb_xcr0_is_valid(svm))
                                 goto vmgexit_err;
                 break;
         case SVM_EXIT_INVD:
                 break;
         case SVM_EXIT_IOIO:
                 if (control->exit_info_1 & SVM_IOIO_STR_MASK) {
                         if (!kvm_ghcb_sw_scratch_is_valid(svm))
                                 goto vmgexit_err;
                 } else {
                         if (!(control->exit_info_1 & SVM_IOIO_TYPE_MASK))
                                 if (!kvm_ghcb_rax_is_valid(svm))
                                         goto vmgexit_err;
                 }
                 break;
         case SVM_EXIT_MSR:
                 if (!kvm_ghcb_rcx_is_valid(svm))
                         goto vmgexit_err;
                 if (control->exit_info_1) {
                         if (!kvm_ghcb_rax_is_valid(svm) ||
                             !kvm_ghcb_rdx_is_valid(svm))
                                 goto vmgexit_err;
                 }
                 break;
         case SVM_EXIT_VMMCALL:
                 if (!kvm_ghcb_rax_is_valid(svm) ||
                     !kvm_ghcb_cpl_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_EXIT_RDTSCP:
                 break;
         case SVM_EXIT_WBINVD:
                 break;
         case SVM_EXIT_MONITOR:
                 if (!kvm_ghcb_rax_is_valid(svm) ||
                     !kvm_ghcb_rcx_is_valid(svm) ||
                     !kvm_ghcb_rdx_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_EXIT_MWAIT:
                 if (!kvm_ghcb_rax_is_valid(svm) ||
                     !kvm_ghcb_rcx_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_VMGEXIT_MMIO_READ:
         case SVM_VMGEXIT_MMIO_WRITE:
                 if (!kvm_ghcb_sw_scratch_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_VMGEXIT_AP_CREATION:
                 if (!sev_snp_guest(vcpu->kvm))
                         goto vmgexit_err;
                 if (lower_32_bits(control->exit_info_1) != SVM_VMGEXIT_AP_DESTROY)
                         if (!kvm_ghcb_rax_is_valid(svm))
                                 goto vmgexit_err;
                 break;
         case SVM_VMGEXIT_NMI_COMPLETE:
         case SVM_VMGEXIT_AP_HLT_LOOP:
         case SVM_VMGEXIT_AP_JUMP_TABLE:
         case SVM_VMGEXIT_UNSUPPORTED_EVENT:
         case SVM_VMGEXIT_HV_FEATURES:
         case SVM_VMGEXIT_TERM_REQUEST:
                 break;
         case SVM_VMGEXIT_PSC:
                 if (!sev_snp_guest(vcpu->kvm) || !kvm_ghcb_sw_scratch_is_valid(svm))
                         goto vmgexit_err;
                 break;
         case SVM_VMGEXIT_GUEST_REQUEST:
         case SVM_VMGEXIT_EXT_GUEST_REQUEST:
                 if (!sev_snp_guest(vcpu->kvm) ||
                     !PAGE_ALIGNED(control->exit_info_1) ||
                     !PAGE_ALIGNED(control->exit_info_2) ||
                     control->exit_info_1 == control->exit_info_2)
                         goto vmgexit_err;
                 break;
         default:
                 reason = GHCB_ERR_INVALID_EVENT;
                 goto vmgexit_err;
         }
 
         return 0;
 
 vmgexit_err:
         if (reason == GHCB_ERR_INVALID_USAGE) {
                 vcpu_unimpl(vcpu, "vmgexit: ghcb usage %#x is not valid\n",
                             svm->sev_es.ghcb->ghcb_usage);
         } else if (reason == GHCB_ERR_INVALID_EVENT) {
                 vcpu_unimpl(vcpu, "vmgexit: exit code %#llx is not valid\n",
                             exit_code);
         } else {
                 vcpu_unimpl(vcpu, "vmgexit: exit code %#llx input is not valid\n",
                             exit_code);
                 dump_ghcb(svm);
         }
 
         ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, reason);
 
         /* Resume the guest to "return" the error code. */
         return 1;
 }
 
 void sev_es_unmap_ghcb(struct vcpu_svm *svm)
 {
         /* Clear any indication that the vCPU is in a type of AP Reset Hold */
         svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_NONE;
 
         if (!svm->sev_es.ghcb)
                 return;
 
         if (svm->sev_es.ghcb_sa_free) {
                 /*
                  * The scratch area lives outside the GHCB, so there is a
                  * buffer that, depending on the operation performed, may
                  * need to be synced, then freed.
                  */
                 if (svm->sev_es.ghcb_sa_sync) {
                         kvm_write_guest(svm->vcpu.kvm,
                                         svm->sev_es.sw_scratch,
                                         svm->sev_es.ghcb_sa,
                                         svm->sev_es.ghcb_sa_len);
                         svm->sev_es.ghcb_sa_sync = false;
                 }
 
                 kvfree(svm->sev_es.ghcb_sa);
                 svm->sev_es.ghcb_sa = NULL;
                 svm->sev_es.ghcb_sa_free = false;
         }
 
         trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->sev_es.ghcb);
 
         sev_es_sync_to_ghcb(svm);
 
         kvm_vcpu_unmap(&svm->vcpu, &svm->sev_es.ghcb_map, true);
         svm->sev_es.ghcb = NULL;
 }
 
 void pre_sev_run(struct vcpu_svm *svm, int cpu)
 {
         struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
         unsigned int asid = sev_get_asid(svm->vcpu.kvm);
 
         /* Assign the asid allocated with this SEV guest */
         svm->asid = asid;
 
         /*
          * Flush guest TLB:
          *
          * 1) when different VMCB for the same ASID is to be run on the same host CPU.
          * 2) or this VMCB was executed on different host CPU in previous VMRUNs.
          */
         if (sd->sev_vmcbs[asid] == svm->vmcb &&
             svm->vcpu.arch.last_vmentry_cpu == cpu)
                 return;
 
         sd->sev_vmcbs[asid] = svm->vmcb;
         svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
         vmcb_mark_dirty(svm->vmcb, VMCB_ASID);
 }
 
 #define GHCB_SCRATCH_AREA_LIMIT         (16ULL * PAGE_SIZE)
 static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
 {
         struct vmcb_control_area *control = &svm->vmcb->control;
         u64 ghcb_scratch_beg, ghcb_scratch_end;
         u64 scratch_gpa_beg, scratch_gpa_end;
         void *scratch_va;
 
         scratch_gpa_beg = svm->sev_es.sw_scratch;
         if (!scratch_gpa_beg) {
                 pr_err("vmgexit: scratch gpa not provided\n");
                 goto e_scratch;
         }
 
         scratch_gpa_end = scratch_gpa_beg + len;
         if (scratch_gpa_end < scratch_gpa_beg) {
                 pr_err("vmgexit: scratch length (%#llx) not valid for scratch address (%#llx)\n",
                        len, scratch_gpa_beg);
                 goto e_scratch;
         }
 
         if ((scratch_gpa_beg & PAGE_MASK) == control->ghcb_gpa) {
                 /* Scratch area begins within GHCB */
                 ghcb_scratch_beg = control->ghcb_gpa +
                                    offsetof(struct ghcb, shared_buffer);
                 ghcb_scratch_end = control->ghcb_gpa +
                                    offsetof(struct ghcb, reserved_0xff0);
 
                 /*
                  * If the scratch area begins within the GHCB, it must be
                  * completely contained in the GHCB shared buffer area.
                  */
                 if (scratch_gpa_beg < ghcb_scratch_beg ||
                     scratch_gpa_end > ghcb_scratch_end) {
                         pr_err("vmgexit: scratch area is outside of GHCB shared buffer area (%#llx - %#llx)\n",
                                scratch_gpa_beg, scratch_gpa_end);
                         goto e_scratch;
                 }
 
                 scratch_va = (void *)svm->sev_es.ghcb;
                 scratch_va += (scratch_gpa_beg - control->ghcb_gpa);
         } else {
                 /*
                  * The guest memory must be read into a kernel buffer, so
                  * limit the size
                  */
                 if (len > GHCB_SCRATCH_AREA_LIMIT) {
                         pr_err("vmgexit: scratch area exceeds KVM limits (%#llx requested, %#llx limit)\n",
                                len, GHCB_SCRATCH_AREA_LIMIT);
                         goto e_scratch;
                 }
                 scratch_va = kvzalloc(len, GFP_KERNEL_ACCOUNT);
                 if (!scratch_va)
                         return -ENOMEM;
 
                 if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) {
                         /* Unable to copy scratch area from guest */
                         pr_err("vmgexit: kvm_read_guest for scratch area failed\n");
 
                         kvfree(scratch_va);
                         return -EFAULT;
                 }
 
                 /*
                  * The scratch area is outside the GHCB. The operation will
                  * dictate whether the buffer needs to be synced before running
                  * the vCPU next time (i.e. a read was requested so the data
                  * must be written back to the guest memory).
                  */
                 svm->sev_es.ghcb_sa_sync = sync;
                 svm->sev_es.ghcb_sa_free = true;
         }
 
         svm->sev_es.ghcb_sa = scratch_va;
         svm->sev_es.ghcb_sa_len = len;
 
         return 0;
 
 e_scratch:
         ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_SCRATCH_AREA);
 
         return 1;
 }
 
 static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask,
                               unsigned int pos)
 {
         svm->vmcb->control.ghcb_gpa &= ~(mask << pos);
         svm->vmcb->control.ghcb_gpa |= (value & mask) << pos;
 }
 
 static u64 get_ghcb_msr_bits(struct vcpu_svm *svm, u64 mask, unsigned int pos)
 {
         return (svm->vmcb->control.ghcb_gpa >> pos) & mask;
 }
 
 static void set_ghcb_msr(struct vcpu_svm *svm, u64 value)
 {
         svm->vmcb->control.ghcb_gpa = value;
 }
 
 static int snp_rmptable_psmash(kvm_pfn_t pfn)
 {
         int ret;
 
         pfn = pfn & ~(KVM_PAGES_PER_HPAGE(PG_LEVEL_2M) - 1);
 
         /*
          * PSMASH_FAIL_INUSE indicates another processor is modifying the
          * entry, so retry until that's no longer the case.
          */
         do {
                 ret = psmash(pfn);
         } while (ret == PSMASH_FAIL_INUSE);
 
         return ret;
 }
 
 static int snp_complete_psc_msr(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
 
         if (vcpu->run->hypercall.ret)
                 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
         else
                 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP);
 
         return 1; /* resume guest */
 }
 
 static int snp_begin_psc_msr(struct vcpu_svm *svm, u64 ghcb_msr)
 {
         u64 gpa = gfn_to_gpa(GHCB_MSR_PSC_REQ_TO_GFN(ghcb_msr));
         u8 op = GHCB_MSR_PSC_REQ_TO_OP(ghcb_msr);
         struct kvm_vcpu *vcpu = &svm->vcpu;
 
         if (op != SNP_PAGE_STATE_PRIVATE && op != SNP_PAGE_STATE_SHARED) {
                 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
                 return 1; /* resume guest */
         }
 
         if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) {
                 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
                 return 1; /* resume guest */
         }
 
         vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
         vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE;
         vcpu->run->hypercall.args[0] = gpa;
         vcpu->run->hypercall.args[1] = 1;
         vcpu->run->hypercall.args[2] = (op == SNP_PAGE_STATE_PRIVATE)
                                        ? KVM_MAP_GPA_RANGE_ENCRYPTED
                                        : KVM_MAP_GPA_RANGE_DECRYPTED;
         vcpu->run->hypercall.args[2] |= KVM_MAP_GPA_RANGE_PAGE_SZ_4K;
 
         vcpu->arch.complete_userspace_io = snp_complete_psc_msr;
 
         return 0; /* forward request to userspace */
 }
 
 struct psc_buffer {
         struct psc_hdr hdr;
         struct psc_entry entries[];
 } __packed;
 
 static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc);
 
 static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret)
 {
         svm->sev_es.psc_inflight = 0;
         svm->sev_es.psc_idx = 0;
         svm->sev_es.psc_2m = false;
         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, psc_ret);
 }
 
 static void __snp_complete_one_psc(struct vcpu_svm *svm)
 {
         struct psc_buffer *psc = svm->sev_es.ghcb_sa;
         struct psc_entry *entries = psc->entries;
         struct psc_hdr *hdr = &psc->hdr;
         __u16 idx;
 
         /*
          * Everything in-flight has been processed successfully. Update the
          * corresponding entries in the guest's PSC buffer and zero out the
          * count of in-flight PSC entries.
          */
         for (idx = svm->sev_es.psc_idx; svm->sev_es.psc_inflight;
              svm->sev_es.psc_inflight--, idx++) {
                 struct psc_entry *entry = &entries[idx];
 
                 entry->cur_page = entry->pagesize ? 512 : 1;
         }
 
         hdr->cur_entry = idx;
 }
 
 static int snp_complete_one_psc(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
         struct psc_buffer *psc = svm->sev_es.ghcb_sa;
 
         if (vcpu->run->hypercall.ret) {
                 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
                 return 1; /* resume guest */
         }
 
         __snp_complete_one_psc(svm);
 
         /* Handle the next range (if any). */
         return snp_begin_psc(svm, psc);
 }
 
 static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc)
 {
         struct psc_entry *entries = psc->entries;
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct psc_hdr *hdr = &psc->hdr;
         struct psc_entry entry_start;
         u16 idx, idx_start, idx_end;
         int npages;
         bool huge;
         u64 gfn;
 
         if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) {
                 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
                 return 1;
         }
 
 next_range:
         /* There should be no other PSCs in-flight at this point. */
         if (WARN_ON_ONCE(svm->sev_es.psc_inflight)) {
                 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
                 return 1;
         }
 
         /*
          * The PSC descriptor buffer can be modified by a misbehaved guest after
          * validation, so take care to only use validated copies of values used
          * for things like array indexing.
          */
         idx_start = hdr->cur_entry;
         idx_end = hdr->end_entry;
 
         if (idx_end >= VMGEXIT_PSC_MAX_COUNT) {
                 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_INVALID_HDR);
                 return 1;
         }
 
         /* Find the start of the next range which needs processing. */
         for (idx = idx_start; idx <= idx_end; idx++, hdr->cur_entry++) {
                 entry_start = entries[idx];
 
                 gfn = entry_start.gfn;
                 huge = entry_start.pagesize;
                 npages = huge ? 512 : 1;
 
                 if (entry_start.cur_page > npages || !IS_ALIGNED(gfn, npages)) {
                         snp_complete_psc(svm, VMGEXIT_PSC_ERROR_INVALID_ENTRY);
                         return 1;
                 }
 
                 if (entry_start.cur_page) {
                         /*
                          * If this is a partially-completed 2M range, force 4K handling
                          * for the remaining pages since they're effectively split at
                          * this point. Subsequent code should ensure this doesn't get
                          * combined with adjacent PSC entries where 2M handling is still
                          * possible.
                          */
                         npages -= entry_start.cur_page;
                         gfn += entry_start.cur_page;
                         huge = false;
                 }
 
                 if (npages)
                         break;
         }
 
         if (idx > idx_end) {
                 /* Nothing more to process. */
                 snp_complete_psc(svm, 0);
                 return 1;
         }
 
         svm->sev_es.psc_2m = huge;
         svm->sev_es.psc_idx = idx;
         svm->sev_es.psc_inflight = 1;
 
         /*
          * Find all subsequent PSC entries that contain adjacent GPA
          * ranges/operations and can be combined into a single
          * KVM_HC_MAP_GPA_RANGE exit.
          */
         while (++idx <= idx_end) {
                 struct psc_entry entry = entries[idx];
 
                 if (entry.operation != entry_start.operation ||
                     entry.gfn != entry_start.gfn + npages ||
                     entry.cur_page || !!entry.pagesize != huge)
                         break;
 
                 svm->sev_es.psc_inflight++;
                 npages += huge ? 512 : 1;
         }
 
         switch (entry_start.operation) {
         case VMGEXIT_PSC_OP_PRIVATE:
         case VMGEXIT_PSC_OP_SHARED:
                 vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
                 vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE;
                 vcpu->run->hypercall.args[0] = gfn_to_gpa(gfn);
                 vcpu->run->hypercall.args[1] = npages;
                 vcpu->run->hypercall.args[2] = entry_start.operation == VMGEXIT_PSC_OP_PRIVATE
                                                ? KVM_MAP_GPA_RANGE_ENCRYPTED
                                                : KVM_MAP_GPA_RANGE_DECRYPTED;
                 vcpu->run->hypercall.args[2] |= entry_start.pagesize
                                                 ? KVM_MAP_GPA_RANGE_PAGE_SZ_2M
                                                 : KVM_MAP_GPA_RANGE_PAGE_SZ_4K;
                 vcpu->arch.complete_userspace_io = snp_complete_one_psc;
                 return 0; /* forward request to userspace */
         default:
                 /*
                  * Only shared/private PSC operations are currently supported, so if the
                  * entire range consists of unsupported operations (e.g. SMASH/UNSMASH),
                  * then consider the entire range completed and avoid exiting to
                  * userspace. In theory snp_complete_psc() can always be called directly
                  * at this point to complete the current range and start the next one,
                  * but that could lead to unexpected levels of recursion.
                  */
                 __snp_complete_one_psc(svm);
                 goto next_range;
         }
 
         unreachable();
 }
 
 static int __sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
 
         WARN_ON(!mutex_is_locked(&svm->sev_es.snp_vmsa_mutex));
 
         /* Mark the vCPU as offline and not runnable */
         vcpu->arch.pv.pv_unhalted = false;
         vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
 
         /* Clear use of the VMSA */
         svm->vmcb->control.vmsa_pa = INVALID_PAGE;
 
         if (VALID_PAGE(svm->sev_es.snp_vmsa_gpa)) {
                 gfn_t gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa);
                 struct kvm_memory_slot *slot;
                 kvm_pfn_t pfn;
 
                 slot = gfn_to_memslot(vcpu->kvm, gfn);
                 if (!slot)
                         return -EINVAL;
 
                 /*
                  * The new VMSA will be private memory guest memory, so
                  * retrieve the PFN from the gmem backend.
                  */
                 if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, NULL))
                         return -EINVAL;
 
                 /*
                  * From this point forward, the VMSA will always be a
                  * guest-mapped page rather than the initial one allocated
                  * by KVM in svm->sev_es.vmsa. In theory, svm->sev_es.vmsa
                  * could be free'd and cleaned up here, but that involves
                  * cleanups like wbinvd_on_all_cpus() which would ideally
                  * be handled during teardown rather than guest boot.
                  * Deferring that also allows the existing logic for SEV-ES
                  * VMSAs to be re-used with minimal SNP-specific changes.
                  */
                 svm->sev_es.snp_has_guest_vmsa = true;
 
                 /* Use the new VMSA */
                 svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn);
 
                 /* Mark the vCPU as runnable */
                 vcpu->arch.pv.pv_unhalted = false;
                 vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 
                 svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
 
                 /*
                  * gmem pages aren't currently migratable, but if this ever
                  * changes then care should be taken to ensure
                  * svm->sev_es.vmsa is pinned through some other means.
                  */
                 kvm_release_pfn_clean(pfn);
         }
 
         /*
          * When replacing the VMSA during SEV-SNP AP creation,
          * mark the VMCB dirty so that full state is always reloaded.
          */
         vmcb_mark_all_dirty(svm->vmcb);
 
         return 0;
 }
 
 /*
  * Invoked as part of svm_vcpu_reset() processing of an init event.
  */
 void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
         int ret;
 
         if (!sev_snp_guest(vcpu->kvm))
                 return;
 
         mutex_lock(&svm->sev_es.snp_vmsa_mutex);
 
         if (!svm->sev_es.snp_ap_waiting_for_reset)
                 goto unlock;
 
         svm->sev_es.snp_ap_waiting_for_reset = false;
 
         ret = __sev_snp_update_protected_guest_state(vcpu);
         if (ret)
                 vcpu_unimpl(vcpu, "snp: AP state update on init failed\n");
 
 unlock:
         mutex_unlock(&svm->sev_es.snp_vmsa_mutex);
 }
 
 static int sev_snp_ap_creation(struct vcpu_svm *svm)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info;
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct kvm_vcpu *target_vcpu;
         struct vcpu_svm *target_svm;
         unsigned int request;
         unsigned int apic_id;
         bool kick;
         int ret;
 
         request = lower_32_bits(svm->vmcb->control.exit_info_1);
         apic_id = upper_32_bits(svm->vmcb->control.exit_info_1);
 
         /* Validate the APIC ID */
         target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, apic_id);
         if (!target_vcpu) {
                 vcpu_unimpl(vcpu, "vmgexit: invalid AP APIC ID [%#x] from guest\n",
                             apic_id);
                 return -EINVAL;
         }
 
         ret = 0;
 
         target_svm = to_svm(target_vcpu);
 
         /*
          * The target vCPU is valid, so the vCPU will be kicked unless the
          * request is for CREATE_ON_INIT. For any errors at this stage, the
          * kick will place the vCPU in an non-runnable state.
          */
         kick = true;
 
         mutex_lock(&target_svm->sev_es.snp_vmsa_mutex);
 
         target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
         target_svm->sev_es.snp_ap_waiting_for_reset = true;
 
         /* Interrupt injection mode shouldn't change for AP creation */
         if (request < SVM_VMGEXIT_AP_DESTROY) {
                 u64 sev_features;
 
                 sev_features = vcpu->arch.regs[VCPU_REGS_RAX];
                 sev_features ^= sev->vmsa_features;
 
                 if (sev_features & SVM_SEV_FEAT_INT_INJ_MODES) {
                         vcpu_unimpl(vcpu, "vmgexit: invalid AP injection mode [%#lx] from guest\n",
                                     vcpu->arch.regs[VCPU_REGS_RAX]);
                         ret = -EINVAL;
                         goto out;
                 }
         }
 
         switch (request) {
         case SVM_VMGEXIT_AP_CREATE_ON_INIT:
                 kick = false;
                 fallthrough;
         case SVM_VMGEXIT_AP_CREATE:
                 if (!page_address_valid(vcpu, svm->vmcb->control.exit_info_2)) {
                         vcpu_unimpl(vcpu, "vmgexit: invalid AP VMSA address [%#llx] from guest\n",
                                     svm->vmcb->control.exit_info_2);
                         ret = -EINVAL;
                         goto out;
                 }
 
                 /*
                  * Malicious guest can RMPADJUST a large page into VMSA which
                  * will hit the SNP erratum where the CPU will incorrectly signal
                  * an RMP violation #PF if a hugepage collides with the RMP entry
                  * of VMSA page, reject the AP CREATE request if VMSA address from
                  * guest is 2M aligned.
                  */
                 if (IS_ALIGNED(svm->vmcb->control.exit_info_2, PMD_SIZE)) {
                         vcpu_unimpl(vcpu,
                                     "vmgexit: AP VMSA address [%llx] from guest is unsafe as it is 2M aligned\n",
                                     svm->vmcb->control.exit_info_2);
                         ret = -EINVAL;
                         goto out;
                 }
 
                 target_svm->sev_es.snp_vmsa_gpa = svm->vmcb->control.exit_info_2;
                 break;
         case SVM_VMGEXIT_AP_DESTROY:
                 break;
         default:
                 vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n",
                             request);
                 ret = -EINVAL;
                 break;
         }
 
 out:
         if (kick) {
                 kvm_make_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu);
                 kvm_vcpu_kick(target_vcpu);
         }
 
         mutex_unlock(&target_svm->sev_es.snp_vmsa_mutex);
 
         return ret;
 }
 
 static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa)
 {
         struct sev_data_snp_guest_request data = {0};
         struct kvm *kvm = svm->vcpu.kvm;
         struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
         sev_ret_code fw_err = 0;
         int ret;
 
         if (!sev_snp_guest(kvm))
                 return -EINVAL;
 
         mutex_lock(&sev->guest_req_mutex);
 
         if (kvm_read_guest(kvm, req_gpa, sev->guest_req_buf, PAGE_SIZE)) {
                 ret = -EIO;
                 goto out_unlock;
         }
 
         data.gctx_paddr = __psp_pa(sev->snp_context);
         data.req_paddr = __psp_pa(sev->guest_req_buf);
         data.res_paddr = __psp_pa(sev->guest_resp_buf);
 
         /*
          * Firmware failures are propagated on to guest, but any other failure
          * condition along the way should be reported to userspace. E.g. if
          * the PSP is dead and commands are timing out.
          */
         ret = sev_issue_cmd(kvm, SEV_CMD_SNP_GUEST_REQUEST, &data, &fw_err);
         if (ret && !fw_err)
                 goto out_unlock;
 
         if (kvm_write_guest(kvm, resp_gpa, sev->guest_resp_buf, PAGE_SIZE)) {
                 ret = -EIO;
                 goto out_unlock;
         }
 
         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, SNP_GUEST_ERR(0, fw_err));
 
         ret = 1; /* resume guest */
 
 out_unlock:
         mutex_unlock(&sev->guest_req_mutex);
         return ret;
 }
 
 static int snp_handle_ext_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa)
 {
         struct kvm *kvm = svm->vcpu.kvm;
         u8 msg_type;
 
         if (!sev_snp_guest(kvm))
                 return -EINVAL;
 
         if (kvm_read_guest(kvm, req_gpa + offsetof(struct snp_guest_msg_hdr, msg_type),
                            &msg_type, 1))
                 return -EIO;
 
         /*
          * As per GHCB spec, requests of type MSG_REPORT_REQ also allow for
          * additional certificate data to be provided alongside the attestation
          * report via the guest-provided data pages indicated by RAX/RBX. The
          * certificate data is optional and requires additional KVM enablement
          * to provide an interface for userspace to provide it, but KVM still
          * needs to be able to handle extended guest requests either way. So
          * provide a stub implementation that will always return an empty
          * certificate table in the guest-provided data pages.
          */
         if (msg_type == SNP_MSG_REPORT_REQ) {
                 struct kvm_vcpu *vcpu = &svm->vcpu;
                 u64 data_npages;
                 gpa_t data_gpa;
 
                 if (!kvm_ghcb_rax_is_valid(svm) || !kvm_ghcb_rbx_is_valid(svm))
                         goto request_invalid;
 
                 data_gpa = vcpu->arch.regs[VCPU_REGS_RAX];
                 data_npages = vcpu->arch.regs[VCPU_REGS_RBX];
 
                 if (!PAGE_ALIGNED(data_gpa))
                         goto request_invalid;
 
                 /*
                  * As per GHCB spec (see "SNP Extended Guest Request"), the
                  * certificate table is terminated by 24-bytes of zeroes.
                  */
                 if (data_npages && kvm_clear_guest(kvm, data_gpa, 24))
                         return -EIO;
         }
 
         return snp_handle_guest_req(svm, req_gpa, resp_gpa);
 
 request_invalid:
         ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
         return 1; /* resume guest */
 }
 
 static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
 {
         struct vmcb_control_area *control = &svm->vmcb->control;
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
         u64 ghcb_info;
         int ret = 1;
 
         ghcb_info = control->ghcb_gpa & GHCB_MSR_INFO_MASK;
 
         trace_kvm_vmgexit_msr_protocol_enter(svm->vcpu.vcpu_id,
                                              control->ghcb_gpa);
 
         switch (ghcb_info) {
         case GHCB_MSR_SEV_INFO_REQ:
                 set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
                                                     GHCB_VERSION_MIN,
                                                     sev_enc_bit));
                 break;
         case GHCB_MSR_CPUID_REQ: {
                 u64 cpuid_fn, cpuid_reg, cpuid_value;
 
                 cpuid_fn = get_ghcb_msr_bits(svm,
                                              GHCB_MSR_CPUID_FUNC_MASK,
                                              GHCB_MSR_CPUID_FUNC_POS);
 
                 /* Initialize the registers needed by the CPUID intercept */
                 vcpu->arch.regs[VCPU_REGS_RAX] = cpuid_fn;
                 vcpu->arch.regs[VCPU_REGS_RCX] = 0;
 
                 ret = svm_invoke_exit_handler(vcpu, SVM_EXIT_CPUID);
                 if (!ret) {
                         /* Error, keep GHCB MSR value as-is */
                         break;
                 }
 
                 cpuid_reg = get_ghcb_msr_bits(svm,
                                               GHCB_MSR_CPUID_REG_MASK,
                                               GHCB_MSR_CPUID_REG_POS);
                 if (cpuid_reg == 0)
                         cpuid_value = vcpu->arch.regs[VCPU_REGS_RAX];
                 else if (cpuid_reg == 1)
                         cpuid_value = vcpu->arch.regs[VCPU_REGS_RBX];
                 else if (cpuid_reg == 2)
                         cpuid_value = vcpu->arch.regs[VCPU_REGS_RCX];
                 else
                         cpuid_value = vcpu->arch.regs[VCPU_REGS_RDX];
 
                 set_ghcb_msr_bits(svm, cpuid_value,
                                   GHCB_MSR_CPUID_VALUE_MASK,
                                   GHCB_MSR_CPUID_VALUE_POS);
 
                 set_ghcb_msr_bits(svm, GHCB_MSR_CPUID_RESP,
                                   GHCB_MSR_INFO_MASK,
                                   GHCB_MSR_INFO_POS);
                 break;
         }
         case GHCB_MSR_AP_RESET_HOLD_REQ:
                 svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_MSR_PROTO;
                 ret = kvm_emulate_ap_reset_hold(&svm->vcpu);
 
                 /*
                  * Preset the result to a non-SIPI return and then only set
                  * the result to non-zero when delivering a SIPI.
                  */
                 set_ghcb_msr_bits(svm, 0,
                                   GHCB_MSR_AP_RESET_HOLD_RESULT_MASK,
                                   GHCB_MSR_AP_RESET_HOLD_RESULT_POS);
 
                 set_ghcb_msr_bits(svm, GHCB_MSR_AP_RESET_HOLD_RESP,
                                   GHCB_MSR_INFO_MASK,
                                   GHCB_MSR_INFO_POS);
                 break;
         case GHCB_MSR_HV_FT_REQ:
                 set_ghcb_msr_bits(svm, GHCB_HV_FT_SUPPORTED,
                                   GHCB_MSR_HV_FT_MASK, GHCB_MSR_HV_FT_POS);
                 set_ghcb_msr_bits(svm, GHCB_MSR_HV_FT_RESP,
                                   GHCB_MSR_INFO_MASK, GHCB_MSR_INFO_POS);
                 break;
         case GHCB_MSR_PREF_GPA_REQ:
                 if (!sev_snp_guest(vcpu->kvm))
                         goto out_terminate;
 
                 set_ghcb_msr_bits(svm, GHCB_MSR_PREF_GPA_NONE, GHCB_MSR_GPA_VALUE_MASK,
                                   GHCB_MSR_GPA_VALUE_POS);
                 set_ghcb_msr_bits(svm, GHCB_MSR_PREF_GPA_RESP, GHCB_MSR_INFO_MASK,
                                   GHCB_MSR_INFO_POS);
                 break;
         case GHCB_MSR_REG_GPA_REQ: {
                 u64 gfn;
 
                 if (!sev_snp_guest(vcpu->kvm))
                         goto out_terminate;
 
                 gfn = get_ghcb_msr_bits(svm, GHCB_MSR_GPA_VALUE_MASK,
                                         GHCB_MSR_GPA_VALUE_POS);
 
                 svm->sev_es.ghcb_registered_gpa = gfn_to_gpa(gfn);
 
                 set_ghcb_msr_bits(svm, gfn, GHCB_MSR_GPA_VALUE_MASK,
                                   GHCB_MSR_GPA_VALUE_POS);
                 set_ghcb_msr_bits(svm, GHCB_MSR_REG_GPA_RESP, GHCB_MSR_INFO_MASK,
                                   GHCB_MSR_INFO_POS);
                 break;
         }
         case GHCB_MSR_PSC_REQ:
                 if (!sev_snp_guest(vcpu->kvm))
                         goto out_terminate;
 
                 ret = snp_begin_psc_msr(svm, control->ghcb_gpa);
                 break;
         case GHCB_MSR_TERM_REQ: {
                 u64 reason_set, reason_code;
 
                 reason_set = get_ghcb_msr_bits(svm,
                                                GHCB_MSR_TERM_REASON_SET_MASK,
                                                GHCB_MSR_TERM_REASON_SET_POS);
                 reason_code = get_ghcb_msr_bits(svm,
                                                 GHCB_MSR_TERM_REASON_MASK,
                                                 GHCB_MSR_TERM_REASON_POS);
                 pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",
                         reason_set, reason_code);
 
                 goto out_terminate;
         }
         default:
                 /* Error, keep GHCB MSR value as-is */
                 break;
         }
 
         trace_kvm_vmgexit_msr_protocol_exit(svm->vcpu.vcpu_id,
                                             control->ghcb_gpa, ret);
 
         return ret;
 
 out_terminate:
         vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
         vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
         vcpu->run->system_event.ndata = 1;
         vcpu->run->system_event.data[0] = control->ghcb_gpa;
 
         return 0;
 }
 
 int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
         struct vmcb_control_area *control = &svm->vmcb->control;
         u64 ghcb_gpa, exit_code;
         int ret;
 
         /* Validate the GHCB */
         ghcb_gpa = control->ghcb_gpa;
         if (ghcb_gpa & GHCB_MSR_INFO_MASK)
                 return sev_handle_vmgexit_msr_protocol(svm);
 
         if (!ghcb_gpa) {
                 vcpu_unimpl(vcpu, "vmgexit: GHCB gpa is not set\n");
 
                 /* Without a GHCB, just return right back to the guest */
                 return 1;
         }
 
         if (kvm_vcpu_map(vcpu, ghcb_gpa >> PAGE_SHIFT, &svm->sev_es.ghcb_map)) {
                 /* Unable to map GHCB from guest */
                 vcpu_unimpl(vcpu, "vmgexit: error mapping GHCB [%#llx] from guest\n",
                             ghcb_gpa);
 
                 /* Without a GHCB, just return right back to the guest */
                 return 1;
         }
 
         svm->sev_es.ghcb = svm->sev_es.ghcb_map.hva;
 
         trace_kvm_vmgexit_enter(vcpu->vcpu_id, svm->sev_es.ghcb);
 
         sev_es_sync_from_ghcb(svm);
 
         /* SEV-SNP guest requires that the GHCB GPA must be registered */
         if (sev_snp_guest(svm->vcpu.kvm) && !ghcb_gpa_is_registered(svm, ghcb_gpa)) {
                 vcpu_unimpl(&svm->vcpu, "vmgexit: GHCB GPA [%#llx] is not registered.\n", ghcb_gpa);
                 return -EINVAL;
         }
 
         ret = sev_es_validate_vmgexit(svm);
         if (ret)
                 return ret;
 
         ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 0);
         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 0);
 
         exit_code = kvm_ghcb_get_sw_exit_code(control);
         switch (exit_code) {
         case SVM_VMGEXIT_MMIO_READ:
                 ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);
                 if (ret)
                         break;
 
                 ret = kvm_sev_es_mmio_read(vcpu,
                                            control->exit_info_1,
                                            control->exit_info_2,
                                            svm->sev_es.ghcb_sa);
                 break;
         case SVM_VMGEXIT_MMIO_WRITE:
                 ret = setup_vmgexit_scratch(svm, false, control->exit_info_2);
                 if (ret)
                         break;
 
                 ret = kvm_sev_es_mmio_write(vcpu,
                                             control->exit_info_1,
                                             control->exit_info_2,
                                             svm->sev_es.ghcb_sa);
                 break;
         case SVM_VMGEXIT_NMI_COMPLETE:
                 ++vcpu->stat.nmi_window_exits;
                 svm->nmi_masked = false;
                 kvm_make_request(KVM_REQ_EVENT, vcpu);
                 ret = 1;
                 break;
         case SVM_VMGEXIT_AP_HLT_LOOP:
                 svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_NAE_EVENT;
                 ret = kvm_emulate_ap_reset_hold(vcpu);
                 break;
         case SVM_VMGEXIT_AP_JUMP_TABLE: {
                 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
 
                 switch (control->exit_info_1) {
                 case 0:
                         /* Set AP jump table address */
                         sev->ap_jump_table = control->exit_info_2;
                         break;
                 case 1:
                         /* Get AP jump table address */
                         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, sev->ap_jump_table);
                         break;
                 default:
                         pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",
                                control->exit_info_1);
                         ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
                         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
                 }
 
                 ret = 1;
                 break;
         }
         case SVM_VMGEXIT_HV_FEATURES:
                 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_HV_FT_SUPPORTED);
 
                 ret = 1;
                 break;
         case SVM_VMGEXIT_TERM_REQUEST:
                 pr_info("SEV-ES guest requested termination: reason %#llx info %#llx\n",
                         control->exit_info_1, control->exit_info_2);
                 vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
                 vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
                 vcpu->run->system_event.ndata = 1;
                 vcpu->run->system_event.data[0] = control->ghcb_gpa;
                 break;
         case SVM_VMGEXIT_PSC:
                 ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);
                 if (ret)
                         break;
 
                 ret = snp_begin_psc(svm, svm->sev_es.ghcb_sa);
                 break;
         case SVM_VMGEXIT_AP_CREATION:
                 ret = sev_snp_ap_creation(svm);
                 if (ret) {
                         ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
                         ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
                 }
 
                 ret = 1;
                 break;
         case SVM_VMGEXIT_GUEST_REQUEST:
                 ret = snp_handle_guest_req(svm, control->exit_info_1, control->exit_info_2);
                 break;
         case SVM_VMGEXIT_EXT_GUEST_REQUEST:
                 ret = snp_handle_ext_guest_req(svm, control->exit_info_1, control->exit_info_2);
                 break;
         case SVM_VMGEXIT_UNSUPPORTED_EVENT:
                 vcpu_unimpl(vcpu,
                             "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
                             control->exit_info_1, control->exit_info_2);
                 ret = -EINVAL;
                 break;
         default:
                 ret = svm_invoke_exit_handler(vcpu, exit_code);
         }
 
         return ret;
 }
 
 int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
 {
         int count;
         int bytes;
         int r;
 
         if (svm->vmcb->control.exit_info_2 > INT_MAX)
                 return -EINVAL;
 
         count = svm->vmcb->control.exit_info_2;
         if (unlikely(check_mul_overflow(count, size, &bytes)))
                 return -EINVAL;
 
         r = setup_vmgexit_scratch(svm, in, bytes);
         if (r)
                 return r;
 
         return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->sev_es.ghcb_sa,
                                     count, in);
 }
 
 static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
 {
         struct kvm_vcpu *vcpu = &svm->vcpu;
 
         if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) {
                 bool v_tsc_aux = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) ||
                                  guest_cpuid_has(vcpu, X86_FEATURE_RDPID);
 
                 set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
         }
 
         /*
          * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
          * the host/guest supports its use.
          *
          * guest_can_use() checks a number of requirements on the host/guest to
          * ensure that MSR_IA32_XSS is available, but it might report true even
          * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host
          * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better
          * to further check that the guest CPUID actually supports
          * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved
          * guests will still get intercepted and caught in the normal
          * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths.
          */
         if (guest_can_use(vcpu, X86_FEATURE_XSAVES) &&
             guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
                 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1);
         else
                 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0);
 }
 
 void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)
 {
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct kvm_cpuid_entry2 *best;
 
         /* For sev guests, the memory encryption bit is not reserved in CR3.  */
         best = kvm_find_cpuid_entry(vcpu, 0x8000001F);
         if (best)
                 vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
 
         if (sev_es_guest(svm->vcpu.kvm))
                 sev_es_vcpu_after_set_cpuid(svm);
 }
 
 static void sev_es_init_vmcb(struct vcpu_svm *svm)
 {
         struct vmcb *vmcb = svm->vmcb01.ptr;
         struct kvm_vcpu *vcpu = &svm->vcpu;
 
         svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE;
 
         /*
          * An SEV-ES guest requires a VMSA area that is a separate from the
          * VMCB page. Do not include the encryption mask on the VMSA physical
          * address since hardware will access it using the guest key.  Note,
          * the VMSA will be NULL if this vCPU is the destination for intrahost
          * migration, and will be copied later.
          */
         if (svm->sev_es.vmsa && !svm->sev_es.snp_has_guest_vmsa)
                 svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
 
         /* Can't intercept CR register access, HV can't modify CR registers */
         svm_clr_intercept(svm, INTERCEPT_CR0_READ);
         svm_clr_intercept(svm, INTERCEPT_CR4_READ);
         svm_clr_intercept(svm, INTERCEPT_CR8_READ);
         svm_clr_intercept(svm, INTERCEPT_CR0_WRITE);
         svm_clr_intercept(svm, INTERCEPT_CR4_WRITE);
         svm_clr_intercept(svm, INTERCEPT_CR8_WRITE);
 
         svm_clr_intercept(svm, INTERCEPT_SELECTIVE_CR0);
 
         /* Track EFER/CR register changes */
         svm_set_intercept(svm, TRAP_EFER_WRITE);
         svm_set_intercept(svm, TRAP_CR0_WRITE);
         svm_set_intercept(svm, TRAP_CR4_WRITE);
         svm_set_intercept(svm, TRAP_CR8_WRITE);
 
         vmcb->control.intercepts[INTERCEPT_DR] = 0;
         if (!sev_vcpu_has_debug_swap(svm)) {
                 vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_READ);
                 vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_WRITE);
                 recalc_intercepts(svm);
         } else {
                 /*
                  * Disable #DB intercept iff DebugSwap is enabled.  KVM doesn't
                  * allow debugging SEV-ES guests, and enables DebugSwap iff
                  * NO_NESTED_DATA_BP is supported, so there's no reason to
                  * intercept #DB when DebugSwap is enabled.  For simplicity
                  * with respect to guest debug, intercept #DB for other VMs
                  * even if NO_NESTED_DATA_BP is supported, i.e. even if the
                  * guest can't DoS the CPU with infinite #DB vectoring.
                  */
                 clr_exception_intercept(svm, DB_VECTOR);
         }
 
         /* Can't intercept XSETBV, HV can't modify XCR0 directly */
         svm_clr_intercept(svm, INTERCEPT_XSETBV);
 
         /* Clear intercepts on selected MSRs */
         set_msr_interception(vcpu, svm->msrpm, MSR_EFER, 1, 1);
         set_msr_interception(vcpu, svm->msrpm, MSR_IA32_CR_PAT, 1, 1);
 }
 
 void sev_init_vmcb(struct vcpu_svm *svm)
 {
         svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;
         clr_exception_intercept(svm, UD_VECTOR);
 
         /*
          * Don't intercept #GP for SEV guests, e.g. for the VMware backdoor, as
          * KVM can't decrypt guest memory to decode the faulting instruction.
          */
         clr_exception_intercept(svm, GP_VECTOR);
 
         if (sev_es_guest(svm->vcpu.kvm))
                 sev_es_init_vmcb(svm);
 }
 
 void sev_es_vcpu_reset(struct vcpu_svm *svm)
 {
         struct kvm_vcpu *vcpu = &svm->vcpu;
         struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
 
         /*
          * Set the GHCB MSR value as per the GHCB specification when emulating
          * vCPU RESET for an SEV-ES guest.
          */
         set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
                                             GHCB_VERSION_MIN,
                                             sev_enc_bit));
 
         mutex_init(&svm->sev_es.snp_vmsa_mutex);
 }
 
 void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa)
 {
         /*
          * All host state for SEV-ES guests is categorized into three swap types
          * based on how it is handled by hardware during a world switch:
          *
          * A: VMRUN:   Host state saved in host save area
          *    VMEXIT:  Host state loaded from host save area
          *
          * B: VMRUN:   Host state _NOT_ saved in host save area
          *    VMEXIT:  Host state loaded from host save area
          *
          * C: VMRUN:   Host state _NOT_ saved in host save area
          *    VMEXIT:  Host state initialized to default(reset) values
          *
          * Manually save type-B state, i.e. state that is loaded by VMEXIT but
          * isn't saved by VMRUN, that isn't already saved by VMSAVE (performed
          * by common SVM code).
          */
         hostsa->xcr0 = kvm_host.xcr0;
         hostsa->pkru = read_pkru();
         hostsa->xss = kvm_host.xss;
 
         /*
          * If DebugSwap is enabled, debug registers are loaded but NOT saved by
          * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU both
          * saves and loads debug registers (Type-A).
          */
         if (sev_vcpu_has_debug_swap(svm)) {
                 hostsa->dr0 = native_get_debugreg(0);
                 hostsa->dr1 = native_get_debugreg(1);
                 hostsa->dr2 = native_get_debugreg(2);
                 hostsa->dr3 = native_get_debugreg(3);
                 hostsa->dr0_addr_mask = amd_get_dr_addr_mask(0);
                 hostsa->dr1_addr_mask = amd_get_dr_addr_mask(1);
                 hostsa->dr2_addr_mask = amd_get_dr_addr_mask(2);
                 hostsa->dr3_addr_mask = amd_get_dr_addr_mask(3);
         }
 }
 
 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
 
         /* First SIPI: Use the values as initially set by the VMM */
         if (!svm->sev_es.received_first_sipi) {
                 svm->sev_es.received_first_sipi = true;
                 return;
         }
 
         /* Subsequent SIPI */
         switch (svm->sev_es.ap_reset_hold_type) {
         case AP_RESET_HOLD_NAE_EVENT:
                 /*
                  * Return from an AP Reset Hold VMGEXIT, where the guest will
                  * set the CS and RIP. Set SW_EXIT_INFO_2 to a non-zero value.
                  */
                 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);
                 break;
         case AP_RESET_HOLD_MSR_PROTO:
                 /*
                  * Return from an AP Reset Hold VMGEXIT, where the guest will
                  * set the CS and RIP. Set GHCB data field to a non-zero value.
                  */
                 set_ghcb_msr_bits(svm, 1,
                                   GHCB_MSR_AP_RESET_HOLD_RESULT_MASK,
                                   GHCB_MSR_AP_RESET_HOLD_RESULT_POS);
 
                 set_ghcb_msr_bits(svm, GHCB_MSR_AP_RESET_HOLD_RESP,
                                   GHCB_MSR_INFO_MASK,
                                   GHCB_MSR_INFO_POS);
                 break;
         default:
                 break;
         }
 }
 
 struct page *snp_safe_alloc_page_node(int node, gfp_t gfp)
 {
         unsigned long pfn;
         struct page *p;
 
         if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
                 return alloc_pages_node(node, gfp | __GFP_ZERO, 0);
 
         /*
          * Allocate an SNP-safe page to workaround the SNP erratum where
          * the CPU will incorrectly signal an RMP violation #PF if a
          * hugepage (2MB or 1GB) collides with the RMP entry of a
          * 2MB-aligned VMCB, VMSA, or AVIC backing page.
          *
          * Allocate one extra page, choose a page which is not
          * 2MB-aligned, and free the other.
          */
         p = alloc_pages_node(node, gfp | __GFP_ZERO, 1);
         if (!p)
                 return NULL;
 
         split_page(p, 1);
 
         pfn = page_to_pfn(p);
         if (IS_ALIGNED(pfn, PTRS_PER_PMD))
                 __free_page(p++);
         else
                 __free_page(p + 1);
 
         return p;
 }
 
 void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
 {
         struct kvm_memory_slot *slot;
         struct kvm *kvm = vcpu->kvm;
         int order, rmp_level, ret;
         bool assigned;
         kvm_pfn_t pfn;
         gfn_t gfn;
 
         gfn = gpa >> PAGE_SHIFT;
 
         /*
          * The only time RMP faults occur for shared pages is when the guest is
          * triggering an RMP fault for an implicit page-state change from
          * shared->private. Implicit page-state changes are forwarded to
          * userspace via KVM_EXIT_MEMORY_FAULT events, however, so RMP faults
          * for shared pages should not end up here.
          */
         if (!kvm_mem_is_private(kvm, gfn)) {
                 pr_warn_ratelimited("SEV: Unexpected RMP fault for non-private GPA 0x%llx\n",
                                     gpa);
                 return;
         }
 
         slot = gfn_to_memslot(kvm, gfn);
         if (!kvm_slot_can_be_private(slot)) {
                 pr_warn_ratelimited("SEV: Unexpected RMP fault, non-private slot for GPA 0x%llx\n",
                                     gpa);
                 return;
         }
 
         ret = kvm_gmem_get_pfn(kvm, slot, gfn, &pfn, &order);
         if (ret) {
                 pr_warn_ratelimited("SEV: Unexpected RMP fault, no backing page for private GPA 0x%llx\n",
                                     gpa);
                 return;
         }
 
         ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
         if (ret || !assigned) {
                 pr_warn_ratelimited("SEV: Unexpected RMP fault, no assigned RMP entry found for GPA 0x%llx PFN 0x%llx error %d\n",
                                     gpa, pfn, ret);
                 goto out_no_trace;
         }
 
         /*
          * There are 2 cases where a PSMASH may be needed to resolve an #NPF
          * with PFERR_GUEST_RMP_BIT set:
          *
          * 1) RMPADJUST/PVALIDATE can trigger an #NPF with PFERR_GUEST_SIZEM
          *    bit set if the guest issues them with a smaller granularity than
          *    what is indicated by the page-size bit in the 2MB RMP entry for
          *    the PFN that backs the GPA.
          *
          * 2) Guest access via NPT can trigger an #NPF if the NPT mapping is
          *    smaller than what is indicated by the 2MB RMP entry for the PFN
          *    that backs the GPA.
          *
          * In both these cases, the corresponding 2M RMP entry needs to
          * be PSMASH'd to 512 4K RMP entries.  If the RMP entry is already
          * split into 4K RMP entries, then this is likely a spurious case which
          * can occur when there are concurrent accesses by the guest to a 2MB
          * GPA range that is backed by a 2MB-aligned PFN who's RMP entry is in
          * the process of being PMASH'd into 4K entries. These cases should
          * resolve automatically on subsequent accesses, so just ignore them
          * here.
          */
         if (rmp_level == PG_LEVEL_4K)
                 goto out;
 
         ret = snp_rmptable_psmash(pfn);
         if (ret) {
                 /*
                  * Look it up again. If it's 4K now then the PSMASH may have
                  * raced with another process and the issue has already resolved
                  * itself.
                  */
                 if (!snp_lookup_rmpentry(pfn, &assigned, &rmp_level) &&
                     assigned && rmp_level == PG_LEVEL_4K)
                         goto out;
 
                 pr_warn_ratelimited("SEV: Unable to split RMP entry for GPA 0x%llx PFN 0x%llx ret %d\n",
                                     gpa, pfn, ret);
         }
 
         kvm_zap_gfn_range(kvm, gfn, gfn + PTRS_PER_PMD);
 out:
         trace_kvm_rmp_fault(vcpu, gpa, pfn, error_code, rmp_level, ret);
 out_no_trace:
         put_page(pfn_to_page(pfn));
 }
 
 static bool is_pfn_range_shared(kvm_pfn_t start, kvm_pfn_t end)
 {
         kvm_pfn_t pfn = start;
 
         while (pfn < end) {
                 int ret, rmp_level;
                 bool assigned;
 
                 ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
                 if (ret) {
                         pr_warn_ratelimited("SEV: Failed to retrieve RMP entry: PFN 0x%llx GFN start 0x%llx GFN end 0x%llx RMP level %d error %d\n",
                                             pfn, start, end, rmp_level, ret);
                         return false;
                 }
 
                 if (assigned) {
                         pr_debug("%s: overlap detected, PFN 0x%llx start 0x%llx end 0x%llx RMP level %d\n",
                                  __func__, pfn, start, end, rmp_level);
                         return false;
                 }
 
                 pfn++;
         }
 
         return true;
 }
 
 static u8 max_level_for_order(int order)
 {
         if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M))
                 return PG_LEVEL_2M;
 
         return PG_LEVEL_4K;
 }
 
 static bool is_large_rmp_possible(struct kvm *kvm, kvm_pfn_t pfn, int order)
 {
         kvm_pfn_t pfn_aligned = ALIGN_DOWN(pfn, PTRS_PER_PMD);
 
         /*
          * If this is a large folio, and the entire 2M range containing the
          * PFN is currently shared, then the entire 2M-aligned range can be
          * set to private via a single 2M RMP entry.
          */
         if (max_level_for_order(order) > PG_LEVEL_4K &&
             is_pfn_range_shared(pfn_aligned, pfn_aligned + PTRS_PER_PMD))
                 return true;
 
         return false;
 }
 
 int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)
 {
         struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
         kvm_pfn_t pfn_aligned;
         gfn_t gfn_aligned;
         int level, rc;
         bool assigned;
 
         if (!sev_snp_guest(kvm))
                 return 0;
 
         rc = snp_lookup_rmpentry(pfn, &assigned, &level);
         if (rc) {
                 pr_err_ratelimited("SEV: Failed to look up RMP entry: GFN %llx PFN %llx error %d\n",
                                    gfn, pfn, rc);
                 return -ENOENT;
         }
 
         if (assigned) {
                 pr_debug("%s: already assigned: gfn %llx pfn %llx max_order %d level %d\n",
                          __func__, gfn, pfn, max_order, level);
                 return 0;
         }
 
         if (is_large_rmp_possible(kvm, pfn, max_order)) {
                 level = PG_LEVEL_2M;
                 pfn_aligned = ALIGN_DOWN(pfn, PTRS_PER_PMD);
                 gfn_aligned = ALIGN_DOWN(gfn, PTRS_PER_PMD);
         } else {
                 level = PG_LEVEL_4K;
                 pfn_aligned = pfn;
                 gfn_aligned = gfn;
         }
 
         rc = rmp_make_private(pfn_aligned, gfn_to_gpa(gfn_aligned), level, sev->asid, false);
         if (rc) {
                 pr_err_ratelimited("SEV: Failed to update RMP entry: GFN %llx PFN %llx level %d error %d\n",
                                    gfn, pfn, level, rc);
                 return -EINVAL;
         }
 
         pr_debug("%s: updated: gfn %llx pfn %llx pfn_aligned %llx max_order %d level %d\n",
                  __func__, gfn, pfn, pfn_aligned, max_order, level);
 
         return 0;
 }
 
 void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end)
 {
         kvm_pfn_t pfn;
 
         if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
                 return;
 
         pr_debug("%s: PFN start 0x%llx PFN end 0x%llx\n", __func__, start, end);
 
         for (pfn = start; pfn < end;) {
                 bool use_2m_update = false;
                 int rc, rmp_level;
                 bool assigned;
 
                 rc = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
                 if (rc || !assigned)
                         goto next_pfn;
 
                 use_2m_update = IS_ALIGNED(pfn, PTRS_PER_PMD) &&
                                 end >= (pfn + PTRS_PER_PMD) &&
                                 rmp_level > PG_LEVEL_4K;
 
                 /*
                  * If an unaligned PFN corresponds to a 2M region assigned as a
                  * large page in the RMP table, PSMASH the region into individual
                  * 4K RMP entries before attempting to convert a 4K sub-page.
                  */
                 if (!use_2m_update && rmp_level > PG_LEVEL_4K) {
                         /*
                          * This shouldn't fail, but if it does, report it, but
                          * still try to update RMP entry to shared and pray this
                          * was a spurious error that can be addressed later.
                          */
                         rc = snp_rmptable_psmash(pfn);
                         WARN_ONCE(rc, "SEV: Failed to PSMASH RMP entry for PFN 0x%llx error %d\n",
                                   pfn, rc);
                 }
 
                 rc = rmp_make_shared(pfn, use_2m_update ? PG_LEVEL_2M : PG_LEVEL_4K);
                 if (WARN_ONCE(rc, "SEV: Failed to update RMP entry for PFN 0x%llx error %d\n",
                               pfn, rc))
                         goto next_pfn;
 
                 /*
                  * SEV-ES avoids host/guest cache coherency issues through
                  * WBINVD hooks issued via MMU notifiers during run-time, and
                  * KVM's VM destroy path at shutdown. Those MMU notifier events
                  * don't cover gmem since there is no requirement to map pages
                  * to a HVA in order to use them for a running guest. While the
                  * shutdown path would still likely cover things for SNP guests,
                  * userspace may also free gmem pages during run-time via
                  * hole-punching operations on the guest_memfd, so flush the
                  * cache entries for these pages before free'ing them back to
                  * the host.
                  */
                 clflush_cache_range(__va(pfn_to_hpa(pfn)),
                                     use_2m_update ? PMD_SIZE : PAGE_SIZE);
 next_pfn:
                 pfn += use_2m_update ? PTRS_PER_PMD : 1;
                 cond_resched();
         }
 }
 
 int sev_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn)
 {
         int level, rc;
         bool assigned;
 
         if (!sev_snp_guest(kvm))
                 return 0;
 
         rc = snp_lookup_rmpentry(pfn, &assigned, &level);
         if (rc || !assigned)
                 return PG_LEVEL_4K;
 
         return level;
 }