1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Kernel-based Virtual Machine driver for Linux
4 *
5 * AMD SVM-SEV support
6 *
7 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
8 */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/kvm_types.h>
12 #include <linux/kvm_host.h>
13 #include <linux/kernel.h>
14 #include <linux/highmem.h>
15 #include <linux/psp.h>
16 #include <linux/psp-sev.h>
17 #include <linux/pagemap.h>
18 #include <linux/swap.h>
19 #include <linux/misc_cgroup.h>
20 #include <linux/processor.h>
21 #include <linux/trace_events.h>
22 #include <uapi/linux/sev-guest.h>
23
24 #include <asm/pkru.h>
25 #include <asm/trapnr.h>
26 #include <asm/fpu/xcr.h>
27 #include <asm/fpu/xstate.h>
28 #include <asm/debugreg.h>
29 #include <asm/sev.h>
30
31 #include "mmu.h"
32 #include "x86.h"
33 #include "svm.h"
34 #include "svm_ops.h"
35 #include "cpuid.h"
36 #include "trace.h"
37
38 #define GHCB_VERSION_MAX 2ULL
39 #define GHCB_VERSION_DEFAULT 2ULL
40 #define GHCB_VERSION_MIN 1ULL
41
42 #define GHCB_HV_FT_SUPPORTED (GHCB_HV_FT_SNP | GHCB_HV_FT_SNP_AP_CREATION)
43
44 /* enable/disable SEV support */
45 static bool sev_enabled = true;
46 module_param_named(sev, sev_enabled, bool, 0444);
47
48 /* enable/disable SEV-ES support */
49 static bool sev_es_enabled = true;
50 module_param_named(sev_es, sev_es_enabled, bool, 0444);
51
52 /* enable/disable SEV-SNP support */
53 static bool sev_snp_enabled = true;
54 module_param_named(sev_snp, sev_snp_enabled, bool, 0444);
55
56 /* enable/disable SEV-ES DebugSwap support */
57 static bool sev_es_debug_swap_enabled = true;
58 module_param_named(debug_swap, sev_es_debug_swap_enabled, bool, 0444);
59 static u64 sev_supported_vmsa_features;
60
61 #define AP_RESET_HOLD_NONE 0
62 #define AP_RESET_HOLD_NAE_EVENT 1
63 #define AP_RESET_HOLD_MSR_PROTO 2
64
65 /* As defined by SEV-SNP Firmware ABI, under "Guest Policy". */
66 #define SNP_POLICY_MASK_API_MINOR GENMASK_ULL(7, 0)
67 #define SNP_POLICY_MASK_API_MAJOR GENMASK_ULL(15, 8)
68 #define SNP_POLICY_MASK_SMT BIT_ULL(16)
69 #define SNP_POLICY_MASK_RSVD_MBO BIT_ULL(17)
70 #define SNP_POLICY_MASK_DEBUG BIT_ULL(19)
71 #define SNP_POLICY_MASK_SINGLE_SOCKET BIT_ULL(20)
72
73 #define SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \
74 SNP_POLICY_MASK_API_MAJOR | \
75 SNP_POLICY_MASK_SMT | \
76 SNP_POLICY_MASK_RSVD_MBO | \
77 SNP_POLICY_MASK_DEBUG | \
78 SNP_POLICY_MASK_SINGLE_SOCKET)
79
80 #define INITIAL_VMSA_GPA 0xFFFFFFFFF000
81
82 static u8 sev_enc_bit;
83 static DECLARE_RWSEM(sev_deactivate_lock);
84 static DEFINE_MUTEX(sev_bitmap_lock);
85 unsigned int max_sev_asid;
86 static unsigned int min_sev_asid;
87 static unsigned long sev_me_mask;
88 static unsigned int nr_asids;
89 static unsigned long *sev_asid_bitmap;
90 static unsigned long *sev_reclaim_asid_bitmap;
91
92 static int snp_decommission_context(struct kvm *kvm);
93
94 struct enc_region {
95 struct list_head list;
96 unsigned long npages;
97 struct page **pages;
98 unsigned long uaddr;
99 unsigned long size;
100 };
101
102 /* Called with the sev_bitmap_lock held, or on shutdown */
103 static int sev_flush_asids(unsigned int min_asid, unsigned int max_asid)
104 {
105 int ret, error = 0;
106 unsigned int asid;
107
108 /* Check if there are any ASIDs to reclaim before performing a flush */
109 asid = find_next_bit(sev_reclaim_asid_bitmap, nr_asids, min_asid);
110 if (asid > max_asid)
111 return -EBUSY;
112
113 /*
114 * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail,
115 * so it must be guarded.
116 */
117 down_write(&sev_deactivate_lock);
118
119 wbinvd_on_all_cpus();
120
121 if (sev_snp_enabled)
122 ret = sev_do_cmd(SEV_CMD_SNP_DF_FLUSH, NULL, &error);
123 else
124 ret = sev_guest_df_flush(&error);
125
126 up_write(&sev_deactivate_lock);
127
128 if (ret)
129 pr_err("SEV%s: DF_FLUSH failed, ret=%d, error=%#x\n",
130 sev_snp_enabled ? "-SNP" : "", ret, error);
131
132 return ret;
133 }
134
135 static inline bool is_mirroring_enc_context(struct kvm *kvm)
136 {
137 return !!to_kvm_sev_info(kvm)->enc_context_owner;
138 }
139
140 static bool sev_vcpu_has_debug_swap(struct vcpu_svm *svm)
141 {
142 struct kvm_vcpu *vcpu = &svm->vcpu;
143 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
144
145 return sev->vmsa_features & SVM_SEV_FEAT_DEBUG_SWAP;
146 }
147
148 /* Must be called with the sev_bitmap_lock held */
149 static bool __sev_recycle_asids(unsigned int min_asid, unsigned int max_asid)
150 {
151 if (sev_flush_asids(min_asid, max_asid))
152 return false;
153
154 /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */
155 bitmap_xor(sev_asid_bitmap, sev_asid_bitmap, sev_reclaim_asid_bitmap,
156 nr_asids);
157 bitmap_zero(sev_reclaim_asid_bitmap, nr_asids);
158
159 return true;
160 }
161
162 static int sev_misc_cg_try_charge(struct kvm_sev_info *sev)
163 {
164 enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
165 return misc_cg_try_charge(type, sev->misc_cg, 1);
166 }
167
168 static void sev_misc_cg_uncharge(struct kvm_sev_info *sev)
169 {
170 enum misc_res_type type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
171 misc_cg_uncharge(type, sev->misc_cg, 1);
172 }
173
174 static int sev_asid_new(struct kvm_sev_info *sev)
175 {
176 /*
177 * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid.
178 * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1.
179 * Note: min ASID can end up larger than the max if basic SEV support is
180 * effectively disabled by disallowing use of ASIDs for SEV guests.
181 */
182 unsigned int min_asid = sev->es_active ? 1 : min_sev_asid;
183 unsigned int max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid;
184 unsigned int asid;
185 bool retry = true;
186 int ret;
187
188 if (min_asid > max_asid)
189 return -ENOTTY;
190
191 WARN_ON(sev->misc_cg);
192 sev->misc_cg = get_current_misc_cg();
193 ret = sev_misc_cg_try_charge(sev);
194 if (ret) {
195 put_misc_cg(sev->misc_cg);
196 sev->misc_cg = NULL;
197 return ret;
198 }
199
200 mutex_lock(&sev_bitmap_lock);
201
202 again:
203 asid = find_next_zero_bit(sev_asid_bitmap, max_asid + 1, min_asid);
204 if (asid > max_asid) {
205 if (retry && __sev_recycle_asids(min_asid, max_asid)) {
206 retry = false;
207 goto again;
208 }
209 mutex_unlock(&sev_bitmap_lock);
210 ret = -EBUSY;
211 goto e_uncharge;
212 }
213
214 __set_bit(asid, sev_asid_bitmap);
215
216 mutex_unlock(&sev_bitmap_lock);
217
218 sev->asid = asid;
219 return 0;
220 e_uncharge:
221 sev_misc_cg_uncharge(sev);
222 put_misc_cg(sev->misc_cg);
223 sev->misc_cg = NULL;
224 return ret;
225 }
226
227 static unsigned int sev_get_asid(struct kvm *kvm)
228 {
229 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
230
231 return sev->asid;
232 }
233
234 static void sev_asid_free(struct kvm_sev_info *sev)
235 {
236 struct svm_cpu_data *sd;
237 int cpu;
238
239 mutex_lock(&sev_bitmap_lock);
240
241 __set_bit(sev->asid, sev_reclaim_asid_bitmap);
242
243 for_each_possible_cpu(cpu) {
244 sd = per_cpu_ptr(&svm_data, cpu);
245 sd->sev_vmcbs[sev->asid] = NULL;
246 }
247
248 mutex_unlock(&sev_bitmap_lock);
249
250 sev_misc_cg_uncharge(sev);
251 put_misc_cg(sev->misc_cg);
252 sev->misc_cg = NULL;
253 }
254
255 static void sev_decommission(unsigned int handle)
256 {
257 struct sev_data_decommission decommission;
258
259 if (!handle)
260 return;
261
262 decommission.handle = handle;
263 sev_guest_decommission(&decommission, NULL);
264 }
265
266 /*
267 * Transition a page to hypervisor-owned/shared state in the RMP table. This
268 * should not fail under normal conditions, but leak the page should that
269 * happen since it will no longer be usable by the host due to RMP protections.
270 */
271 static int kvm_rmp_make_shared(struct kvm *kvm, u64 pfn, enum pg_level level)
272 {
273 if (KVM_BUG_ON(rmp_make_shared(pfn, level), kvm)) {
274 snp_leak_pages(pfn, page_level_size(level) >> PAGE_SHIFT);
275 return -EIO;
276 }
277
278 return 0;
279 }
280
281 /*
282 * Certain page-states, such as Pre-Guest and Firmware pages (as documented
283 * in Chapter 5 of the SEV-SNP Firmware ABI under "Page States") cannot be
284 * directly transitioned back to normal/hypervisor-owned state via RMPUPDATE
285 * unless they are reclaimed first.
286 *
287 * Until they are reclaimed and subsequently transitioned via RMPUPDATE, they
288 * might not be usable by the host due to being set as immutable or still
289 * being associated with a guest ASID.
290 *
291 * Bug the VM and leak the page if reclaim fails, or if the RMP entry can't be
292 * converted back to shared, as the page is no longer usable due to RMP
293 * protections, and it's infeasible for the guest to continue on.
294 */
295 static int snp_page_reclaim(struct kvm *kvm, u64 pfn)
296 {
297 struct sev_data_snp_page_reclaim data = {0};
298 int fw_err, rc;
299
300 data.paddr = __sme_set(pfn << PAGE_SHIFT);
301 rc = sev_do_cmd(SEV_CMD_SNP_PAGE_RECLAIM, &data, &fw_err);
302 if (KVM_BUG(rc, kvm, "Failed to reclaim PFN %llx, rc %d fw_err %d", pfn, rc, fw_err)) {
303 snp_leak_pages(pfn, 1);
304 return -EIO;
305 }
306
307 if (kvm_rmp_make_shared(kvm, pfn, PG_LEVEL_4K))
308 return -EIO;
309
310 return rc;
311 }
312
313 static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
314 {
315 struct sev_data_deactivate deactivate;
316
317 if (!handle)
318 return;
319
320 deactivate.handle = handle;
321
322 /* Guard DEACTIVATE against WBINVD/DF_FLUSH used in ASID recycling */
323 down_read(&sev_deactivate_lock);
324 sev_guest_deactivate(&deactivate, NULL);
325 up_read(&sev_deactivate_lock);
326
327 sev_decommission(handle);
328 }
329
330 /*
331 * This sets up bounce buffers/firmware pages to handle SNP Guest Request
332 * messages (e.g. attestation requests). See "SNP Guest Request" in the GHCB
333 * 2.0 specification for more details.
334 *
335 * Technically, when an SNP Guest Request is issued, the guest will provide its
336 * own request/response pages, which could in theory be passed along directly
337 * to firmware rather than using bounce pages. However, these pages would need
338 * special care:
339 *
340 * - Both pages are from shared guest memory, so they need to be protected
341 * from migration/etc. occurring while firmware reads/writes to them. At a
342 * minimum, this requires elevating the ref counts and potentially needing
343 * an explicit pinning of the memory. This places additional restrictions
344 * on what type of memory backends userspace can use for shared guest
345 * memory since there is some reliance on using refcounted pages.
346 *
347 * - The response page needs to be switched to Firmware-owned[1] state
348 * before the firmware can write to it, which can lead to potential
349 * host RMP #PFs if the guest is misbehaved and hands the host a
350 * guest page that KVM might write to for other reasons (e.g. virtio
351 * buffers/etc.).
352 *
353 * Both of these issues can be avoided completely by using separately-allocated
354 * bounce pages for both the request/response pages and passing those to
355 * firmware instead. So that's what is being set up here.
356 *
357 * Guest requests rely on message sequence numbers to ensure requests are
358 * issued to firmware in the order the guest issues them, so concurrent guest
359 * requests generally shouldn't happen. But a misbehaved guest could issue
360 * concurrent guest requests in theory, so a mutex is used to serialize
361 * access to the bounce buffers.
362 *
363 * [1] See the "Page States" section of the SEV-SNP Firmware ABI for more
364 * details on Firmware-owned pages, along with "RMP and VMPL Access Checks"
365 * in the APM for details on the related RMP restrictions.
366 */
367 static int snp_guest_req_init(struct kvm *kvm)
368 {
369 struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
370 struct page *req_page;
371
372 req_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
373 if (!req_page)
374 return -ENOMEM;
375
376 sev->guest_resp_buf = snp_alloc_firmware_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
377 if (!sev->guest_resp_buf) {
378 __free_page(req_page);
379 return -EIO;
380 }
381
382 sev->guest_req_buf = page_address(req_page);
383 mutex_init(&sev->guest_req_mutex);
384
385 return 0;
386 }
387
388 static void snp_guest_req_cleanup(struct kvm *kvm)
389 {
390 struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
391
392 if (sev->guest_resp_buf)
393 snp_free_firmware_page(sev->guest_resp_buf);
394
395 if (sev->guest_req_buf)
396 __free_page(virt_to_page(sev->guest_req_buf));
397
398 sev->guest_req_buf = NULL;
399 sev->guest_resp_buf = NULL;
400 }
401
402 static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
403 struct kvm_sev_init *data,
404 unsigned long vm_type)
405 {
406 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
407 struct sev_platform_init_args init_args = {0};
408 bool es_active = vm_type != KVM_X86_SEV_VM;
409 u64 valid_vmsa_features = es_active ? sev_supported_vmsa_features : 0;
410 int ret;
411
412 if (kvm->created_vcpus)
413 return -EINVAL;
414
415 if (data->flags)
416 return -EINVAL;
417
418 if (data->vmsa_features & ~valid_vmsa_features)
419 return -EINVAL;
420
421 if (data->ghcb_version > GHCB_VERSION_MAX || (!es_active && data->ghcb_version))
422 return -EINVAL;
423
424 if (unlikely(sev->active))
425 return -EINVAL;
426
427 sev->active = true;
428 sev->es_active = es_active;
429 sev->vmsa_features = data->vmsa_features;
430 sev->ghcb_version = data->ghcb_version;
431
432 /*
433 * Currently KVM supports the full range of mandatory features defined
434 * by version 2 of the GHCB protocol, so default to that for SEV-ES
435 * guests created via KVM_SEV_INIT2.
436 */
437 if (sev->es_active && !sev->ghcb_version)
438 sev->ghcb_version = GHCB_VERSION_DEFAULT;
439
440 if (vm_type == KVM_X86_SNP_VM)
441 sev->vmsa_features |= SVM_SEV_FEAT_SNP_ACTIVE;
442
443 ret = sev_asid_new(sev);
444 if (ret)
445 goto e_no_asid;
446
447 init_args.probe = false;
448 ret = sev_platform_init(&init_args);
449 if (ret)
450 goto e_free;
451
452 /* This needs to happen after SEV/SNP firmware initialization. */
453 if (vm_type == KVM_X86_SNP_VM && snp_guest_req_init(kvm))
454 goto e_free;
455
456 INIT_LIST_HEAD(&sev->regions_list);
457 INIT_LIST_HEAD(&sev->mirror_vms);
458 sev->need_init = false;
459
460 kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_SEV);
461
462 return 0;
463
464 e_free:
465 argp->error = init_args.error;
466 sev_asid_free(sev);
467 sev->asid = 0;
468 e_no_asid:
469 sev->vmsa_features = 0;
470 sev->es_active = false;
471 sev->active = false;
472 return ret;
473 }
474
475 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
476 {
477 struct kvm_sev_init data = {
478 .vmsa_features = 0,
479 .ghcb_version = 0,
480 };
481 unsigned long vm_type;
482
483 if (kvm->arch.vm_type != KVM_X86_DEFAULT_VM)
484 return -EINVAL;
485
486 vm_type = (argp->id == KVM_SEV_INIT ? KVM_X86_SEV_VM : KVM_X86_SEV_ES_VM);
487
488 /*
489 * KVM_SEV_ES_INIT has been deprecated by KVM_SEV_INIT2, so it will
490 * continue to only ever support the minimal GHCB protocol version.
491 */
492 if (vm_type == KVM_X86_SEV_ES_VM)
493 data.ghcb_version = GHCB_VERSION_MIN;
494
495 return __sev_guest_init(kvm, argp, &data, vm_type);
496 }
497
498 static int sev_guest_init2(struct kvm *kvm, struct kvm_sev_cmd *argp)
499 {
500 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
501 struct kvm_sev_init data;
502
503 if (!sev->need_init)
504 return -EINVAL;
505
506 if (kvm->arch.vm_type != KVM_X86_SEV_VM &&
507 kvm->arch.vm_type != KVM_X86_SEV_ES_VM &&
508 kvm->arch.vm_type != KVM_X86_SNP_VM)
509 return -EINVAL;
510
511 if (copy_from_user(&data, u64_to_user_ptr(argp->data), sizeof(data)))
512 return -EFAULT;
513
514 return __sev_guest_init(kvm, argp, &data, kvm->arch.vm_type);
515 }
516
517 static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
518 {
519 unsigned int asid = sev_get_asid(kvm);
520 struct sev_data_activate activate;
521 int ret;
522
523 /* activate ASID on the given handle */
524 activate.handle = handle;
525 activate.asid = asid;
526 ret = sev_guest_activate(&activate, error);
527
528 return ret;
529 }
530
531 static int __sev_issue_cmd(int fd, int id, void *data, int *error)
532 {
533 struct fd f;
534 int ret;
535
536 f = fdget(fd);
537 if (!f.file)
538 return -EBADF;
539
540 ret = sev_issue_cmd_external_user(f.file, id, data, error);
541
542 fdput(f);
543 return ret;
544 }
545
546 static int sev_issue_cmd(struct kvm *kvm, int id, void *data, int *error)
547 {
548 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
549
550 return __sev_issue_cmd(sev->fd, id, data, error);
551 }
552
553 static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
554 {
555 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
556 struct sev_data_launch_start start;
557 struct kvm_sev_launch_start params;
558 void *dh_blob, *session_blob;
559 int *error = &argp->error;
560 int ret;
561
562 if (!sev_guest(kvm))
563 return -ENOTTY;
564
565 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
566 return -EFAULT;
567
568 memset(&start, 0, sizeof(start));
569
570 dh_blob = NULL;
571 if (params.dh_uaddr) {
572 dh_blob = psp_copy_user_blob(params.dh_uaddr, params.dh_len);
573 if (IS_ERR(dh_blob))
574 return PTR_ERR(dh_blob);
575
576 start.dh_cert_address = __sme_set(__pa(dh_blob));
577 start.dh_cert_len = params.dh_len;
578 }
579
580 session_blob = NULL;
581 if (params.session_uaddr) {
582 session_blob = psp_copy_user_blob(params.session_uaddr, params.session_len);
583 if (IS_ERR(session_blob)) {
584 ret = PTR_ERR(session_blob);
585 goto e_free_dh;
586 }
587
588 start.session_address = __sme_set(__pa(session_blob));
589 start.session_len = params.session_len;
590 }
591
592 start.handle = params.handle;
593 start.policy = params.policy;
594
595 /* create memory encryption context */
596 ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_LAUNCH_START, &start, error);
597 if (ret)
598 goto e_free_session;
599
600 /* Bind ASID to this guest */
601 ret = sev_bind_asid(kvm, start.handle, error);
602 if (ret) {
603 sev_decommission(start.handle);
604 goto e_free_session;
605 }
606
607 /* return handle to userspace */
608 params.handle = start.handle;
609 if (copy_to_user(u64_to_user_ptr(argp->data), ¶ms, sizeof(params))) {
610 sev_unbind_asid(kvm, start.handle);
611 ret = -EFAULT;
612 goto e_free_session;
613 }
614
615 sev->handle = start.handle;
616 sev->fd = argp->sev_fd;
617
618 e_free_session:
619 kfree(session_blob);
620 e_free_dh:
621 kfree(dh_blob);
622 return ret;
623 }
624
625 static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
626 unsigned long ulen, unsigned long *n,
627 int write)
628 {
629 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
630 unsigned long npages, size;
631 int npinned;
632 unsigned long locked, lock_limit;
633 struct page **pages;
634 unsigned long first, last;
635 int ret;
636
637 lockdep_assert_held(&kvm->lock);
638
639 if (ulen == 0 || uaddr + ulen < uaddr)
640 return ERR_PTR(-EINVAL);
641
642 /* Calculate number of pages. */
643 first = (uaddr & PAGE_MASK) >> PAGE_SHIFT;
644 last = ((uaddr + ulen - 1) & PAGE_MASK) >> PAGE_SHIFT;
645 npages = (last - first + 1);
646
647 locked = sev->pages_locked + npages;
648 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
649 if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
650 pr_err("SEV: %lu locked pages exceed the lock limit of %lu.\n", locked, lock_limit);
651 return ERR_PTR(-ENOMEM);
652 }
653
654 if (WARN_ON_ONCE(npages > INT_MAX))
655 return ERR_PTR(-EINVAL);
656
657 /* Avoid using vmalloc for smaller buffers. */
658 size = npages * sizeof(struct page *);
659 if (size > PAGE_SIZE)
660 pages = __vmalloc(size, GFP_KERNEL_ACCOUNT);
661 else
662 pages = kmalloc(size, GFP_KERNEL_ACCOUNT);
663
664 if (!pages)
665 return ERR_PTR(-ENOMEM);
666
667 /* Pin the user virtual address. */
668 npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);
669 if (npinned != npages) {
670 pr_err("SEV: Failure locking %lu pages.\n", npages);
671 ret = -ENOMEM;
672 goto err;
673 }
674
675 *n = npages;
676 sev->pages_locked = locked;
677
678 return pages;
679
680 err:
681 if (npinned > 0)
682 unpin_user_pages(pages, npinned);
683
684 kvfree(pages);
685 return ERR_PTR(ret);
686 }
687
688 static void sev_unpin_memory(struct kvm *kvm, struct page **pages,
689 unsigned long npages)
690 {
691 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
692
693 unpin_user_pages(pages, npages);
694 kvfree(pages);
695 sev->pages_locked -= npages;
696 }
697
698 static void sev_clflush_pages(struct page *pages[], unsigned long npages)
699 {
700 uint8_t *page_virtual;
701 unsigned long i;
702
703 if (this_cpu_has(X86_FEATURE_SME_COHERENT) || npages == 0 ||
704 pages == NULL)
705 return;
706
707 for (i = 0; i < npages; i++) {
708 page_virtual = kmap_local_page(pages[i]);
709 clflush_cache_range(page_virtual, PAGE_SIZE);
710 kunmap_local(page_virtual);
711 cond_resched();
712 }
713 }
714
715 static unsigned long get_num_contig_pages(unsigned long idx,
716 struct page **inpages, unsigned long npages)
717 {
718 unsigned long paddr, next_paddr;
719 unsigned long i = idx + 1, pages = 1;
720
721 /* find the number of contiguous pages starting from idx */
722 paddr = __sme_page_pa(inpages[idx]);
723 while (i < npages) {
724 next_paddr = __sme_page_pa(inpages[i++]);
725 if ((paddr + PAGE_SIZE) == next_paddr) {
726 pages++;
727 paddr = next_paddr;
728 continue;
729 }
730 break;
731 }
732
733 return pages;
734 }
735
736 static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
737 {
738 unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
739 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
740 struct kvm_sev_launch_update_data params;
741 struct sev_data_launch_update_data data;
742 struct page **inpages;
743 int ret;
744
745 if (!sev_guest(kvm))
746 return -ENOTTY;
747
748 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
749 return -EFAULT;
750
751 vaddr = params.uaddr;
752 size = params.len;
753 vaddr_end = vaddr + size;
754
755 /* Lock the user memory. */
756 inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
757 if (IS_ERR(inpages))
758 return PTR_ERR(inpages);
759
760 /*
761 * Flush (on non-coherent CPUs) before LAUNCH_UPDATE encrypts pages in
762 * place; the cache may contain the data that was written unencrypted.
763 */
764 sev_clflush_pages(inpages, npages);
765
766 data.reserved = 0;
767 data.handle = sev->handle;
768
769 for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) {
770 int offset, len;
771
772 /*
773 * If the user buffer is not page-aligned, calculate the offset
774 * within the page.
775 */
776 offset = vaddr & (PAGE_SIZE - 1);
777
778 /* Calculate the number of pages that can be encrypted in one go. */
779 pages = get_num_contig_pages(i, inpages, npages);
780
781 len = min_t(size_t, ((pages * PAGE_SIZE) - offset), size);
782
783 data.len = len;
784 data.address = __sme_page_pa(inpages[i]) + offset;
785 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_DATA, &data, &argp->error);
786 if (ret)
787 goto e_unpin;
788
789 size -= len;
790 next_vaddr = vaddr + len;
791 }
792
793 e_unpin:
794 /* content of memory is updated, mark pages dirty */
795 for (i = 0; i < npages; i++) {
796 set_page_dirty_lock(inpages[i]);
797 mark_page_accessed(inpages[i]);
798 }
799 /* unlock the user pages */
800 sev_unpin_memory(kvm, inpages, npages);
801 return ret;
802 }
803
804 static int sev_es_sync_vmsa(struct vcpu_svm *svm)
805 {
806 struct kvm_vcpu *vcpu = &svm->vcpu;
807 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
808 struct sev_es_save_area *save = svm->sev_es.vmsa;
809 struct xregs_state *xsave;
810 const u8 *s;
811 u8 *d;
812 int i;
813
814 /* Check some debug related fields before encrypting the VMSA */
815 if (svm->vcpu.guest_debug || (svm->vmcb->save.dr7 & ~DR7_FIXED_1))
816 return -EINVAL;
817
818 /*
819 * SEV-ES will use a VMSA that is pointed to by the VMCB, not
820 * the traditional VMSA that is part of the VMCB. Copy the
821 * traditional VMSA as it has been built so far (in prep
822 * for LAUNCH_UPDATE_VMSA) to be the initial SEV-ES state.
823 */
824 memcpy(save, &svm->vmcb->save, sizeof(svm->vmcb->save));
825
826 /* Sync registgers */
827 save->rax = svm->vcpu.arch.regs[VCPU_REGS_RAX];
828 save->rbx = svm->vcpu.arch.regs[VCPU_REGS_RBX];
829 save->rcx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
830 save->rdx = svm->vcpu.arch.regs[VCPU_REGS_RDX];
831 save->rsp = svm->vcpu.arch.regs[VCPU_REGS_RSP];
832 save->rbp = svm->vcpu.arch.regs[VCPU_REGS_RBP];
833 save->rsi = svm->vcpu.arch.regs[VCPU_REGS_RSI];
834 save->rdi = svm->vcpu.arch.regs[VCPU_REGS_RDI];
835 #ifdef CONFIG_X86_64
836 save->r8 = svm->vcpu.arch.regs[VCPU_REGS_R8];
837 save->r9 = svm->vcpu.arch.regs[VCPU_REGS_R9];
838 save->r10 = svm->vcpu.arch.regs[VCPU_REGS_R10];
839 save->r11 = svm->vcpu.arch.regs[VCPU_REGS_R11];
840 save->r12 = svm->vcpu.arch.regs[VCPU_REGS_R12];
841 save->r13 = svm->vcpu.arch.regs[VCPU_REGS_R13];
842 save->r14 = svm->vcpu.arch.regs[VCPU_REGS_R14];
843 save->r15 = svm->vcpu.arch.regs[VCPU_REGS_R15];
844 #endif
845 save->rip = svm->vcpu.arch.regs[VCPU_REGS_RIP];
846
847 /* Sync some non-GPR registers before encrypting */
848 save->xcr0 = svm->vcpu.arch.xcr0;
849 save->pkru = svm->vcpu.arch.pkru;
850 save->xss = svm->vcpu.arch.ia32_xss;
851 save->dr6 = svm->vcpu.arch.dr6;
852
853 save->sev_features = sev->vmsa_features;
854
855 /*
856 * Skip FPU and AVX setup with KVM_SEV_ES_INIT to avoid
857 * breaking older measurements.
858 */
859 if (vcpu->kvm->arch.vm_type != KVM_X86_DEFAULT_VM) {
860 xsave = &vcpu->arch.guest_fpu.fpstate->regs.xsave;
861 save->x87_dp = xsave->i387.rdp;
862 save->mxcsr = xsave->i387.mxcsr;
863 save->x87_ftw = xsave->i387.twd;
864 save->x87_fsw = xsave->i387.swd;
865 save->x87_fcw = xsave->i387.cwd;
866 save->x87_fop = xsave->i387.fop;
867 save->x87_ds = 0;
868 save->x87_cs = 0;
869 save->x87_rip = xsave->i387.rip;
870
871 for (i = 0; i < 8; i++) {
872 /*
873 * The format of the x87 save area is undocumented and
874 * definitely not what you would expect. It consists of
875 * an 8*8 bytes area with bytes 0-7, and an 8*2 bytes
876 * area with bytes 8-9 of each register.
877 */
878 d = save->fpreg_x87 + i * 8;
879 s = ((u8 *)xsave->i387.st_space) + i * 16;
880 memcpy(d, s, 8);
881 save->fpreg_x87[64 + i * 2] = s[8];
882 save->fpreg_x87[64 + i * 2 + 1] = s[9];
883 }
884 memcpy(save->fpreg_xmm, xsave->i387.xmm_space, 256);
885
886 s = get_xsave_addr(xsave, XFEATURE_YMM);
887 if (s)
888 memcpy(save->fpreg_ymm, s, 256);
889 else
890 memset(save->fpreg_ymm, 0, 256);
891 }
892
893 pr_debug("Virtual Machine Save Area (VMSA):\n");
894 print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, save, sizeof(*save), false);
895
896 return 0;
897 }
898
899 static int __sev_launch_update_vmsa(struct kvm *kvm, struct kvm_vcpu *vcpu,
900 int *error)
901 {
902 struct sev_data_launch_update_vmsa vmsa;
903 struct vcpu_svm *svm = to_svm(vcpu);
904 int ret;
905
906 if (vcpu->guest_debug) {
907 pr_warn_once("KVM_SET_GUEST_DEBUG for SEV-ES guest is not supported");
908 return -EINVAL;
909 }
910
911 /* Perform some pre-encryption checks against the VMSA */
912 ret = sev_es_sync_vmsa(svm);
913 if (ret)
914 return ret;
915
916 /*
917 * The LAUNCH_UPDATE_VMSA command will perform in-place encryption of
918 * the VMSA memory content (i.e it will write the same memory region
919 * with the guest's key), so invalidate it first.
920 */
921 clflush_cache_range(svm->sev_es.vmsa, PAGE_SIZE);
922
923 vmsa.reserved = 0;
924 vmsa.handle = to_kvm_sev_info(kvm)->handle;
925 vmsa.address = __sme_pa(svm->sev_es.vmsa);
926 vmsa.len = PAGE_SIZE;
927 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_VMSA, &vmsa, error);
928 if (ret)
929 return ret;
930
931 /*
932 * SEV-ES guests maintain an encrypted version of their FPU
933 * state which is restored and saved on VMRUN and VMEXIT.
934 * Mark vcpu->arch.guest_fpu->fpstate as scratch so it won't
935 * do xsave/xrstor on it.
936 */
937 fpstate_set_confidential(&vcpu->arch.guest_fpu);
938 vcpu->arch.guest_state_protected = true;
939
940 /*
941 * SEV-ES guest mandates LBR Virtualization to be _always_ ON. Enable it
942 * only after setting guest_state_protected because KVM_SET_MSRS allows
943 * dynamic toggling of LBRV (for performance reason) on write access to
944 * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.
945 */
946 svm_enable_lbrv(vcpu);
947 return 0;
948 }
949
950 static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
951 {
952 struct kvm_vcpu *vcpu;
953 unsigned long i;
954 int ret;
955
956 if (!sev_es_guest(kvm))
957 return -ENOTTY;
958
959 kvm_for_each_vcpu(i, vcpu, kvm) {
960 ret = mutex_lock_killable(&vcpu->mutex);
961 if (ret)
962 return ret;
963
964 ret = __sev_launch_update_vmsa(kvm, vcpu, &argp->error);
965
966 mutex_unlock(&vcpu->mutex);
967 if (ret)
968 return ret;
969 }
970
971 return 0;
972 }
973
974 static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
975 {
976 void __user *measure = u64_to_user_ptr(argp->data);
977 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
978 struct sev_data_launch_measure data;
979 struct kvm_sev_launch_measure params;
980 void __user *p = NULL;
981 void *blob = NULL;
982 int ret;
983
984 if (!sev_guest(kvm))
985 return -ENOTTY;
986
987 if (copy_from_user(¶ms, measure, sizeof(params)))
988 return -EFAULT;
989
990 memset(&data, 0, sizeof(data));
991
992 /* User wants to query the blob length */
993 if (!params.len)
994 goto cmd;
995
996 p = u64_to_user_ptr(params.uaddr);
997 if (p) {
998 if (params.len > SEV_FW_BLOB_MAX_SIZE)
999 return -EINVAL;
1000
1001 blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
1002 if (!blob)
1003 return -ENOMEM;
1004
1005 data.address = __psp_pa(blob);
1006 data.len = params.len;
1007 }
1008
1009 cmd:
1010 data.handle = sev->handle;
1011 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_MEASURE, &data, &argp->error);
1012
1013 /*
1014 * If we query the session length, FW responded with expected data.
1015 */
1016 if (!params.len)
1017 goto done;
1018
1019 if (ret)
1020 goto e_free_blob;
1021
1022 if (blob) {
1023 if (copy_to_user(p, blob, params.len))
1024 ret = -EFAULT;
1025 }
1026
1027 done:
1028 params.len = data.len;
1029 if (copy_to_user(measure, ¶ms, sizeof(params)))
1030 ret = -EFAULT;
1031 e_free_blob:
1032 kfree(blob);
1033 return ret;
1034 }
1035
1036 static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1037 {
1038 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1039 struct sev_data_launch_finish data;
1040
1041 if (!sev_guest(kvm))
1042 return -ENOTTY;
1043
1044 data.handle = sev->handle;
1045 return sev_issue_cmd(kvm, SEV_CMD_LAUNCH_FINISH, &data, &argp->error);
1046 }
1047
1048 static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
1049 {
1050 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1051 struct kvm_sev_guest_status params;
1052 struct sev_data_guest_status data;
1053 int ret;
1054
1055 if (!sev_guest(kvm))
1056 return -ENOTTY;
1057
1058 memset(&data, 0, sizeof(data));
1059
1060 data.handle = sev->handle;
1061 ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, &data, &argp->error);
1062 if (ret)
1063 return ret;
1064
1065 params.policy = data.policy;
1066 params.state = data.state;
1067 params.handle = data.handle;
1068
1069 if (copy_to_user(u64_to_user_ptr(argp->data), ¶ms, sizeof(params)))
1070 ret = -EFAULT;
1071
1072 return ret;
1073 }
1074
1075 static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src,
1076 unsigned long dst, int size,
1077 int *error, bool enc)
1078 {
1079 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1080 struct sev_data_dbg data;
1081
1082 data.reserved = 0;
1083 data.handle = sev->handle;
1084 data.dst_addr = dst;
1085 data.src_addr = src;
1086 data.len = size;
1087
1088 return sev_issue_cmd(kvm,
1089 enc ? SEV_CMD_DBG_ENCRYPT : SEV_CMD_DBG_DECRYPT,
1090 &data, error);
1091 }
1092
1093 static int __sev_dbg_decrypt(struct kvm *kvm, unsigned long src_paddr,
1094 unsigned long dst_paddr, int sz, int *err)
1095 {
1096 int offset;
1097
1098 /*
1099 * Its safe to read more than we are asked, caller should ensure that
1100 * destination has enough space.
1101 */
1102 offset = src_paddr & 15;
1103 src_paddr = round_down(src_paddr, 16);
1104 sz = round_up(sz + offset, 16);
1105
1106 return __sev_issue_dbg_cmd(kvm, src_paddr, dst_paddr, sz, err, false);
1107 }
1108
1109 static int __sev_dbg_decrypt_user(struct kvm *kvm, unsigned long paddr,
1110 void __user *dst_uaddr,
1111 unsigned long dst_paddr,
1112 int size, int *err)
1113 {
1114 struct page *tpage = NULL;
1115 int ret, offset;
1116
1117 /* if inputs are not 16-byte then use intermediate buffer */
1118 if (!IS_ALIGNED(dst_paddr, 16) ||
1119 !IS_ALIGNED(paddr, 16) ||
1120 !IS_ALIGNED(size, 16)) {
1121 tpage = (void *)alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
1122 if (!tpage)
1123 return -ENOMEM;
1124
1125 dst_paddr = __sme_page_pa(tpage);
1126 }
1127
1128 ret = __sev_dbg_decrypt(kvm, paddr, dst_paddr, size, err);
1129 if (ret)
1130 goto e_free;
1131
1132 if (tpage) {
1133 offset = paddr & 15;
1134 if (copy_to_user(dst_uaddr, page_address(tpage) + offset, size))
1135 ret = -EFAULT;
1136 }
1137
1138 e_free:
1139 if (tpage)
1140 __free_page(tpage);
1141
1142 return ret;
1143 }
1144
1145 static int __sev_dbg_encrypt_user(struct kvm *kvm, unsigned long paddr,
1146 void __user *vaddr,
1147 unsigned long dst_paddr,
1148 void __user *dst_vaddr,
1149 int size, int *error)
1150 {
1151 struct page *src_tpage = NULL;
1152 struct page *dst_tpage = NULL;
1153 int ret, len = size;
1154
1155 /* If source buffer is not aligned then use an intermediate buffer */
1156 if (!IS_ALIGNED((unsigned long)vaddr, 16)) {
1157 src_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
1158 if (!src_tpage)
1159 return -ENOMEM;
1160
1161 if (copy_from_user(page_address(src_tpage), vaddr, size)) {
1162 __free_page(src_tpage);
1163 return -EFAULT;
1164 }
1165
1166 paddr = __sme_page_pa(src_tpage);
1167 }
1168
1169 /*
1170 * If destination buffer or length is not aligned then do read-modify-write:
1171 * - decrypt destination in an intermediate buffer
1172 * - copy the source buffer in an intermediate buffer
1173 * - use the intermediate buffer as source buffer
1174 */
1175 if (!IS_ALIGNED((unsigned long)dst_vaddr, 16) || !IS_ALIGNED(size, 16)) {
1176 int dst_offset;
1177
1178 dst_tpage = alloc_page(GFP_KERNEL_ACCOUNT);
1179 if (!dst_tpage) {
1180 ret = -ENOMEM;
1181 goto e_free;
1182 }
1183
1184 ret = __sev_dbg_decrypt(kvm, dst_paddr,
1185 __sme_page_pa(dst_tpage), size, error);
1186 if (ret)
1187 goto e_free;
1188
1189 /*
1190 * If source is kernel buffer then use memcpy() otherwise
1191 * copy_from_user().
1192 */
1193 dst_offset = dst_paddr & 15;
1194
1195 if (src_tpage)
1196 memcpy(page_address(dst_tpage) + dst_offset,
1197 page_address(src_tpage), size);
1198 else {
1199 if (copy_from_user(page_address(dst_tpage) + dst_offset,
1200 vaddr, size)) {
1201 ret = -EFAULT;
1202 goto e_free;
1203 }
1204 }
1205
1206 paddr = __sme_page_pa(dst_tpage);
1207 dst_paddr = round_down(dst_paddr, 16);
1208 len = round_up(size, 16);
1209 }
1210
1211 ret = __sev_issue_dbg_cmd(kvm, paddr, dst_paddr, len, error, true);
1212
1213 e_free:
1214 if (src_tpage)
1215 __free_page(src_tpage);
1216 if (dst_tpage)
1217 __free_page(dst_tpage);
1218 return ret;
1219 }
1220
1221 static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
1222 {
1223 unsigned long vaddr, vaddr_end, next_vaddr;
1224 unsigned long dst_vaddr;
1225 struct page **src_p, **dst_p;
1226 struct kvm_sev_dbg debug;
1227 unsigned long n;
1228 unsigned int size;
1229 int ret;
1230
1231 if (!sev_guest(kvm))
1232 return -ENOTTY;
1233
1234 if (copy_from_user(&debug, u64_to_user_ptr(argp->data), sizeof(debug)))
1235 return -EFAULT;
1236
1237 if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
1238 return -EINVAL;
1239 if (!debug.dst_uaddr)
1240 return -EINVAL;
1241
1242 vaddr = debug.src_uaddr;
1243 size = debug.len;
1244 vaddr_end = vaddr + size;
1245 dst_vaddr = debug.dst_uaddr;
1246
1247 for (; vaddr < vaddr_end; vaddr = next_vaddr) {
1248 int len, s_off, d_off;
1249
1250 /* lock userspace source and destination page */
1251 src_p = sev_pin_memory(kvm, vaddr & PAGE_MASK, PAGE_SIZE, &n, 0);
1252 if (IS_ERR(src_p))
1253 return PTR_ERR(src_p);
1254
1255 dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1);
1256 if (IS_ERR(dst_p)) {
1257 sev_unpin_memory(kvm, src_p, n);
1258 return PTR_ERR(dst_p);
1259 }
1260
1261 /*
1262 * Flush (on non-coherent CPUs) before DBG_{DE,EN}CRYPT read or modify
1263 * the pages; flush the destination too so that future accesses do not
1264 * see stale data.
1265 */
1266 sev_clflush_pages(src_p, 1);
1267 sev_clflush_pages(dst_p, 1);
1268
1269 /*
1270 * Since user buffer may not be page aligned, calculate the
1271 * offset within the page.
1272 */
1273 s_off = vaddr & ~PAGE_MASK;
1274 d_off = dst_vaddr & ~PAGE_MASK;
1275 len = min_t(size_t, (PAGE_SIZE - s_off), size);
1276
1277 if (dec)
1278 ret = __sev_dbg_decrypt_user(kvm,
1279 __sme_page_pa(src_p[0]) + s_off,
1280 (void __user *)dst_vaddr,
1281 __sme_page_pa(dst_p[0]) + d_off,
1282 len, &argp->error);
1283 else
1284 ret = __sev_dbg_encrypt_user(kvm,
1285 __sme_page_pa(src_p[0]) + s_off,
1286 (void __user *)vaddr,
1287 __sme_page_pa(dst_p[0]) + d_off,
1288 (void __user *)dst_vaddr,
1289 len, &argp->error);
1290
1291 sev_unpin_memory(kvm, src_p, n);
1292 sev_unpin_memory(kvm, dst_p, n);
1293
1294 if (ret)
1295 goto err;
1296
1297 next_vaddr = vaddr + len;
1298 dst_vaddr = dst_vaddr + len;
1299 size -= len;
1300 }
1301 err:
1302 return ret;
1303 }
1304
1305 static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
1306 {
1307 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1308 struct sev_data_launch_secret data;
1309 struct kvm_sev_launch_secret params;
1310 struct page **pages;
1311 void *blob, *hdr;
1312 unsigned long n, i;
1313 int ret, offset;
1314
1315 if (!sev_guest(kvm))
1316 return -ENOTTY;
1317
1318 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
1319 return -EFAULT;
1320
1321 pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1);
1322 if (IS_ERR(pages))
1323 return PTR_ERR(pages);
1324
1325 /*
1326 * Flush (on non-coherent CPUs) before LAUNCH_SECRET encrypts pages in
1327 * place; the cache may contain the data that was written unencrypted.
1328 */
1329 sev_clflush_pages(pages, n);
1330
1331 /*
1332 * The secret must be copied into contiguous memory region, lets verify
1333 * that userspace memory pages are contiguous before we issue command.
1334 */
1335 if (get_num_contig_pages(0, pages, n) != n) {
1336 ret = -EINVAL;
1337 goto e_unpin_memory;
1338 }
1339
1340 memset(&data, 0, sizeof(data));
1341
1342 offset = params.guest_uaddr & (PAGE_SIZE - 1);
1343 data.guest_address = __sme_page_pa(pages[0]) + offset;
1344 data.guest_len = params.guest_len;
1345
1346 blob = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
1347 if (IS_ERR(blob)) {
1348 ret = PTR_ERR(blob);
1349 goto e_unpin_memory;
1350 }
1351
1352 data.trans_address = __psp_pa(blob);
1353 data.trans_len = params.trans_len;
1354
1355 hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
1356 if (IS_ERR(hdr)) {
1357 ret = PTR_ERR(hdr);
1358 goto e_free_blob;
1359 }
1360 data.hdr_address = __psp_pa(hdr);
1361 data.hdr_len = params.hdr_len;
1362
1363 data.handle = sev->handle;
1364 ret = sev_issue_cmd(kvm, SEV_CMD_LAUNCH_UPDATE_SECRET, &data, &argp->error);
1365
1366 kfree(hdr);
1367
1368 e_free_blob:
1369 kfree(blob);
1370 e_unpin_memory:
1371 /* content of memory is updated, mark pages dirty */
1372 for (i = 0; i < n; i++) {
1373 set_page_dirty_lock(pages[i]);
1374 mark_page_accessed(pages[i]);
1375 }
1376 sev_unpin_memory(kvm, pages, n);
1377 return ret;
1378 }
1379
1380 static int sev_get_attestation_report(struct kvm *kvm, struct kvm_sev_cmd *argp)
1381 {
1382 void __user *report = u64_to_user_ptr(argp->data);
1383 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1384 struct sev_data_attestation_report data;
1385 struct kvm_sev_attestation_report params;
1386 void __user *p;
1387 void *blob = NULL;
1388 int ret;
1389
1390 if (!sev_guest(kvm))
1391 return -ENOTTY;
1392
1393 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
1394 return -EFAULT;
1395
1396 memset(&data, 0, sizeof(data));
1397
1398 /* User wants to query the blob length */
1399 if (!params.len)
1400 goto cmd;
1401
1402 p = u64_to_user_ptr(params.uaddr);
1403 if (p) {
1404 if (params.len > SEV_FW_BLOB_MAX_SIZE)
1405 return -EINVAL;
1406
1407 blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
1408 if (!blob)
1409 return -ENOMEM;
1410
1411 data.address = __psp_pa(blob);
1412 data.len = params.len;
1413 memcpy(data.mnonce, params.mnonce, sizeof(params.mnonce));
1414 }
1415 cmd:
1416 data.handle = sev->handle;
1417 ret = sev_issue_cmd(kvm, SEV_CMD_ATTESTATION_REPORT, &data, &argp->error);
1418 /*
1419 * If we query the session length, FW responded with expected data.
1420 */
1421 if (!params.len)
1422 goto done;
1423
1424 if (ret)
1425 goto e_free_blob;
1426
1427 if (blob) {
1428 if (copy_to_user(p, blob, params.len))
1429 ret = -EFAULT;
1430 }
1431
1432 done:
1433 params.len = data.len;
1434 if (copy_to_user(report, ¶ms, sizeof(params)))
1435 ret = -EFAULT;
1436 e_free_blob:
1437 kfree(blob);
1438 return ret;
1439 }
1440
1441 /* Userspace wants to query session length. */
1442 static int
1443 __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp,
1444 struct kvm_sev_send_start *params)
1445 {
1446 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1447 struct sev_data_send_start data;
1448 int ret;
1449
1450 memset(&data, 0, sizeof(data));
1451 data.handle = sev->handle;
1452 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
1453
1454 params->session_len = data.session_len;
1455 if (copy_to_user(u64_to_user_ptr(argp->data), params,
1456 sizeof(struct kvm_sev_send_start)))
1457 ret = -EFAULT;
1458
1459 return ret;
1460 }
1461
1462 static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
1463 {
1464 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1465 struct sev_data_send_start data;
1466 struct kvm_sev_send_start params;
1467 void *amd_certs, *session_data;
1468 void *pdh_cert, *plat_certs;
1469 int ret;
1470
1471 if (!sev_guest(kvm))
1472 return -ENOTTY;
1473
1474 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data),
1475 sizeof(struct kvm_sev_send_start)))
1476 return -EFAULT;
1477
1478 /* if session_len is zero, userspace wants to query the session length */
1479 if (!params.session_len)
1480 return __sev_send_start_query_session_length(kvm, argp,
1481 ¶ms);
1482
1483 /* some sanity checks */
1484 if (!params.pdh_cert_uaddr || !params.pdh_cert_len ||
1485 !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE)
1486 return -EINVAL;
1487
1488 /* allocate the memory to hold the session data blob */
1489 session_data = kzalloc(params.session_len, GFP_KERNEL_ACCOUNT);
1490 if (!session_data)
1491 return -ENOMEM;
1492
1493 /* copy the certificate blobs from userspace */
1494 pdh_cert = psp_copy_user_blob(params.pdh_cert_uaddr,
1495 params.pdh_cert_len);
1496 if (IS_ERR(pdh_cert)) {
1497 ret = PTR_ERR(pdh_cert);
1498 goto e_free_session;
1499 }
1500
1501 plat_certs = psp_copy_user_blob(params.plat_certs_uaddr,
1502 params.plat_certs_len);
1503 if (IS_ERR(plat_certs)) {
1504 ret = PTR_ERR(plat_certs);
1505 goto e_free_pdh;
1506 }
1507
1508 amd_certs = psp_copy_user_blob(params.amd_certs_uaddr,
1509 params.amd_certs_len);
1510 if (IS_ERR(amd_certs)) {
1511 ret = PTR_ERR(amd_certs);
1512 goto e_free_plat_cert;
1513 }
1514
1515 /* populate the FW SEND_START field with system physical address */
1516 memset(&data, 0, sizeof(data));
1517 data.pdh_cert_address = __psp_pa(pdh_cert);
1518 data.pdh_cert_len = params.pdh_cert_len;
1519 data.plat_certs_address = __psp_pa(plat_certs);
1520 data.plat_certs_len = params.plat_certs_len;
1521 data.amd_certs_address = __psp_pa(amd_certs);
1522 data.amd_certs_len = params.amd_certs_len;
1523 data.session_address = __psp_pa(session_data);
1524 data.session_len = params.session_len;
1525 data.handle = sev->handle;
1526
1527 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, &data, &argp->error);
1528
1529 if (!ret && copy_to_user(u64_to_user_ptr(params.session_uaddr),
1530 session_data, params.session_len)) {
1531 ret = -EFAULT;
1532 goto e_free_amd_cert;
1533 }
1534
1535 params.policy = data.policy;
1536 params.session_len = data.session_len;
1537 if (copy_to_user(u64_to_user_ptr(argp->data), ¶ms,
1538 sizeof(struct kvm_sev_send_start)))
1539 ret = -EFAULT;
1540
1541 e_free_amd_cert:
1542 kfree(amd_certs);
1543 e_free_plat_cert:
1544 kfree(plat_certs);
1545 e_free_pdh:
1546 kfree(pdh_cert);
1547 e_free_session:
1548 kfree(session_data);
1549 return ret;
1550 }
1551
1552 /* Userspace wants to query either header or trans length. */
1553 static int
1554 __sev_send_update_data_query_lengths(struct kvm *kvm, struct kvm_sev_cmd *argp,
1555 struct kvm_sev_send_update_data *params)
1556 {
1557 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1558 struct sev_data_send_update_data data;
1559 int ret;
1560
1561 memset(&data, 0, sizeof(data));
1562 data.handle = sev->handle;
1563 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
1564
1565 params->hdr_len = data.hdr_len;
1566 params->trans_len = data.trans_len;
1567
1568 if (copy_to_user(u64_to_user_ptr(argp->data), params,
1569 sizeof(struct kvm_sev_send_update_data)))
1570 ret = -EFAULT;
1571
1572 return ret;
1573 }
1574
1575 static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
1576 {
1577 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1578 struct sev_data_send_update_data data;
1579 struct kvm_sev_send_update_data params;
1580 void *hdr, *trans_data;
1581 struct page **guest_page;
1582 unsigned long n;
1583 int ret, offset;
1584
1585 if (!sev_guest(kvm))
1586 return -ENOTTY;
1587
1588 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data),
1589 sizeof(struct kvm_sev_send_update_data)))
1590 return -EFAULT;
1591
1592 /* userspace wants to query either header or trans length */
1593 if (!params.trans_len || !params.hdr_len)
1594 return __sev_send_update_data_query_lengths(kvm, argp, ¶ms);
1595
1596 if (!params.trans_uaddr || !params.guest_uaddr ||
1597 !params.guest_len || !params.hdr_uaddr)
1598 return -EINVAL;
1599
1600 /* Check if we are crossing the page boundary */
1601 offset = params.guest_uaddr & (PAGE_SIZE - 1);
1602 if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
1603 return -EINVAL;
1604
1605 /* Pin guest memory */
1606 guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
1607 PAGE_SIZE, &n, 0);
1608 if (IS_ERR(guest_page))
1609 return PTR_ERR(guest_page);
1610
1611 /* allocate memory for header and transport buffer */
1612 ret = -ENOMEM;
1613 hdr = kzalloc(params.hdr_len, GFP_KERNEL_ACCOUNT);
1614 if (!hdr)
1615 goto e_unpin;
1616
1617 trans_data = kzalloc(params.trans_len, GFP_KERNEL_ACCOUNT);
1618 if (!trans_data)
1619 goto e_free_hdr;
1620
1621 memset(&data, 0, sizeof(data));
1622 data.hdr_address = __psp_pa(hdr);
1623 data.hdr_len = params.hdr_len;
1624 data.trans_address = __psp_pa(trans_data);
1625 data.trans_len = params.trans_len;
1626
1627 /* The SEND_UPDATE_DATA command requires C-bit to be always set. */
1628 data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
1629 data.guest_address |= sev_me_mask;
1630 data.guest_len = params.guest_len;
1631 data.handle = sev->handle;
1632
1633 ret = sev_issue_cmd(kvm, SEV_CMD_SEND_UPDATE_DATA, &data, &argp->error);
1634
1635 if (ret)
1636 goto e_free_trans_data;
1637
1638 /* copy transport buffer to user space */
1639 if (copy_to_user(u64_to_user_ptr(params.trans_uaddr),
1640 trans_data, params.trans_len)) {
1641 ret = -EFAULT;
1642 goto e_free_trans_data;
1643 }
1644
1645 /* Copy packet header to userspace. */
1646 if (copy_to_user(u64_to_user_ptr(params.hdr_uaddr), hdr,
1647 params.hdr_len))
1648 ret = -EFAULT;
1649
1650 e_free_trans_data:
1651 kfree(trans_data);
1652 e_free_hdr:
1653 kfree(hdr);
1654 e_unpin:
1655 sev_unpin_memory(kvm, guest_page, n);
1656
1657 return ret;
1658 }
1659
1660 static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1661 {
1662 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1663 struct sev_data_send_finish data;
1664
1665 if (!sev_guest(kvm))
1666 return -ENOTTY;
1667
1668 data.handle = sev->handle;
1669 return sev_issue_cmd(kvm, SEV_CMD_SEND_FINISH, &data, &argp->error);
1670 }
1671
1672 static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp)
1673 {
1674 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1675 struct sev_data_send_cancel data;
1676
1677 if (!sev_guest(kvm))
1678 return -ENOTTY;
1679
1680 data.handle = sev->handle;
1681 return sev_issue_cmd(kvm, SEV_CMD_SEND_CANCEL, &data, &argp->error);
1682 }
1683
1684 static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
1685 {
1686 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1687 struct sev_data_receive_start start;
1688 struct kvm_sev_receive_start params;
1689 int *error = &argp->error;
1690 void *session_data;
1691 void *pdh_data;
1692 int ret;
1693
1694 if (!sev_guest(kvm))
1695 return -ENOTTY;
1696
1697 /* Get parameter from the userspace */
1698 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data),
1699 sizeof(struct kvm_sev_receive_start)))
1700 return -EFAULT;
1701
1702 /* some sanity checks */
1703 if (!params.pdh_uaddr || !params.pdh_len ||
1704 !params.session_uaddr || !params.session_len)
1705 return -EINVAL;
1706
1707 pdh_data = psp_copy_user_blob(params.pdh_uaddr, params.pdh_len);
1708 if (IS_ERR(pdh_data))
1709 return PTR_ERR(pdh_data);
1710
1711 session_data = psp_copy_user_blob(params.session_uaddr,
1712 params.session_len);
1713 if (IS_ERR(session_data)) {
1714 ret = PTR_ERR(session_data);
1715 goto e_free_pdh;
1716 }
1717
1718 memset(&start, 0, sizeof(start));
1719 start.handle = params.handle;
1720 start.policy = params.policy;
1721 start.pdh_cert_address = __psp_pa(pdh_data);
1722 start.pdh_cert_len = params.pdh_len;
1723 start.session_address = __psp_pa(session_data);
1724 start.session_len = params.session_len;
1725
1726 /* create memory encryption context */
1727 ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_RECEIVE_START, &start,
1728 error);
1729 if (ret)
1730 goto e_free_session;
1731
1732 /* Bind ASID to this guest */
1733 ret = sev_bind_asid(kvm, start.handle, error);
1734 if (ret) {
1735 sev_decommission(start.handle);
1736 goto e_free_session;
1737 }
1738
1739 params.handle = start.handle;
1740 if (copy_to_user(u64_to_user_ptr(argp->data),
1741 ¶ms, sizeof(struct kvm_sev_receive_start))) {
1742 ret = -EFAULT;
1743 sev_unbind_asid(kvm, start.handle);
1744 goto e_free_session;
1745 }
1746
1747 sev->handle = start.handle;
1748 sev->fd = argp->sev_fd;
1749
1750 e_free_session:
1751 kfree(session_data);
1752 e_free_pdh:
1753 kfree(pdh_data);
1754
1755 return ret;
1756 }
1757
1758 static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
1759 {
1760 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1761 struct kvm_sev_receive_update_data params;
1762 struct sev_data_receive_update_data data;
1763 void *hdr = NULL, *trans = NULL;
1764 struct page **guest_page;
1765 unsigned long n;
1766 int ret, offset;
1767
1768 if (!sev_guest(kvm))
1769 return -EINVAL;
1770
1771 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data),
1772 sizeof(struct kvm_sev_receive_update_data)))
1773 return -EFAULT;
1774
1775 if (!params.hdr_uaddr || !params.hdr_len ||
1776 !params.guest_uaddr || !params.guest_len ||
1777 !params.trans_uaddr || !params.trans_len)
1778 return -EINVAL;
1779
1780 /* Check if we are crossing the page boundary */
1781 offset = params.guest_uaddr & (PAGE_SIZE - 1);
1782 if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
1783 return -EINVAL;
1784
1785 hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
1786 if (IS_ERR(hdr))
1787 return PTR_ERR(hdr);
1788
1789 trans = psp_copy_user_blob(params.trans_uaddr, params.trans_len);
1790 if (IS_ERR(trans)) {
1791 ret = PTR_ERR(trans);
1792 goto e_free_hdr;
1793 }
1794
1795 memset(&data, 0, sizeof(data));
1796 data.hdr_address = __psp_pa(hdr);
1797 data.hdr_len = params.hdr_len;
1798 data.trans_address = __psp_pa(trans);
1799 data.trans_len = params.trans_len;
1800
1801 /* Pin guest memory */
1802 guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
1803 PAGE_SIZE, &n, 1);
1804 if (IS_ERR(guest_page)) {
1805 ret = PTR_ERR(guest_page);
1806 goto e_free_trans;
1807 }
1808
1809 /*
1810 * Flush (on non-coherent CPUs) before RECEIVE_UPDATE_DATA, the PSP
1811 * encrypts the written data with the guest's key, and the cache may
1812 * contain dirty, unencrypted data.
1813 */
1814 sev_clflush_pages(guest_page, n);
1815
1816 /* The RECEIVE_UPDATE_DATA command requires C-bit to be always set. */
1817 data.guest_address = (page_to_pfn(guest_page[0]) << PAGE_SHIFT) + offset;
1818 data.guest_address |= sev_me_mask;
1819 data.guest_len = params.guest_len;
1820 data.handle = sev->handle;
1821
1822 ret = sev_issue_cmd(kvm, SEV_CMD_RECEIVE_UPDATE_DATA, &data,
1823 &argp->error);
1824
1825 sev_unpin_memory(kvm, guest_page, n);
1826
1827 e_free_trans:
1828 kfree(trans);
1829 e_free_hdr:
1830 kfree(hdr);
1831
1832 return ret;
1833 }
1834
1835 static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
1836 {
1837 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
1838 struct sev_data_receive_finish data;
1839
1840 if (!sev_guest(kvm))
1841 return -ENOTTY;
1842
1843 data.handle = sev->handle;
1844 return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error);
1845 }
1846
1847 static bool is_cmd_allowed_from_mirror(u32 cmd_id)
1848 {
1849 /*
1850 * Allow mirrors VM to call KVM_SEV_LAUNCH_UPDATE_VMSA to enable SEV-ES
1851 * active mirror VMs. Also allow the debugging and status commands.
1852 */
1853 if (cmd_id == KVM_SEV_LAUNCH_UPDATE_VMSA ||
1854 cmd_id == KVM_SEV_GUEST_STATUS || cmd_id == KVM_SEV_DBG_DECRYPT ||
1855 cmd_id == KVM_SEV_DBG_ENCRYPT)
1856 return true;
1857
1858 return false;
1859 }
1860
1861 static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
1862 {
1863 struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
1864 struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
1865 int r = -EBUSY;
1866
1867 if (dst_kvm == src_kvm)
1868 return -EINVAL;
1869
1870 /*
1871 * Bail if these VMs are already involved in a migration to avoid
1872 * deadlock between two VMs trying to migrate to/from each other.
1873 */
1874 if (atomic_cmpxchg_acquire(&dst_sev->migration_in_progress, 0, 1))
1875 return -EBUSY;
1876
1877 if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
1878 goto release_dst;
1879
1880 r = -EINTR;
1881 if (mutex_lock_killable(&dst_kvm->lock))
1882 goto release_src;
1883 if (mutex_lock_killable_nested(&src_kvm->lock, SINGLE_DEPTH_NESTING))
1884 goto unlock_dst;
1885 return 0;
1886
1887 unlock_dst:
1888 mutex_unlock(&dst_kvm->lock);
1889 release_src:
1890 atomic_set_release(&src_sev->migration_in_progress, 0);
1891 release_dst:
1892 atomic_set_release(&dst_sev->migration_in_progress, 0);
1893 return r;
1894 }
1895
1896 static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
1897 {
1898 struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
1899 struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
1900
1901 mutex_unlock(&dst_kvm->lock);
1902 mutex_unlock(&src_kvm->lock);
1903 atomic_set_release(&dst_sev->migration_in_progress, 0);
1904 atomic_set_release(&src_sev->migration_in_progress, 0);
1905 }
1906
1907 /* vCPU mutex subclasses. */
1908 enum sev_migration_role {
1909 SEV_MIGRATION_SOURCE = 0,
1910 SEV_MIGRATION_TARGET,
1911 SEV_NR_MIGRATION_ROLES,
1912 };
1913
1914 static int sev_lock_vcpus_for_migration(struct kvm *kvm,
1915 enum sev_migration_role role)
1916 {
1917 struct kvm_vcpu *vcpu;
1918 unsigned long i, j;
1919
1920 kvm_for_each_vcpu(i, vcpu, kvm) {
1921 if (mutex_lock_killable_nested(&vcpu->mutex, role))
1922 goto out_unlock;
1923
1924 #ifdef CONFIG_PROVE_LOCKING
1925 if (!i)
1926 /*
1927 * Reset the role to one that avoids colliding with
1928 * the role used for the first vcpu mutex.
1929 */
1930 role = SEV_NR_MIGRATION_ROLES;
1931 else
1932 mutex_release(&vcpu->mutex.dep_map, _THIS_IP_);
1933 #endif
1934 }
1935
1936 return 0;
1937
1938 out_unlock:
1939
1940 kvm_for_each_vcpu(j, vcpu, kvm) {
1941 if (i == j)
1942 break;
1943
1944 #ifdef CONFIG_PROVE_LOCKING
1945 if (j)
1946 mutex_acquire(&vcpu->mutex.dep_map, role, 0, _THIS_IP_);
1947 #endif
1948
1949 mutex_unlock(&vcpu->mutex);
1950 }
1951 return -EINTR;
1952 }
1953
1954 static void sev_unlock_vcpus_for_migration(struct kvm *kvm)
1955 {
1956 struct kvm_vcpu *vcpu;
1957 unsigned long i;
1958 bool first = true;
1959
1960 kvm_for_each_vcpu(i, vcpu, kvm) {
1961 if (first)
1962 first = false;
1963 else
1964 mutex_acquire(&vcpu->mutex.dep_map,
1965 SEV_NR_MIGRATION_ROLES, 0, _THIS_IP_);
1966
1967 mutex_unlock(&vcpu->mutex);
1968 }
1969 }
1970
1971 static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm)
1972 {
1973 struct kvm_sev_info *dst = &to_kvm_svm(dst_kvm)->sev_info;
1974 struct kvm_sev_info *src = &to_kvm_svm(src_kvm)->sev_info;
1975 struct kvm_vcpu *dst_vcpu, *src_vcpu;
1976 struct vcpu_svm *dst_svm, *src_svm;
1977 struct kvm_sev_info *mirror;
1978 unsigned long i;
1979
1980 dst->active = true;
1981 dst->asid = src->asid;
1982 dst->handle = src->handle;
1983 dst->pages_locked = src->pages_locked;
1984 dst->enc_context_owner = src->enc_context_owner;
1985 dst->es_active = src->es_active;
1986 dst->vmsa_features = src->vmsa_features;
1987
1988 src->asid = 0;
1989 src->active = false;
1990 src->handle = 0;
1991 src->pages_locked = 0;
1992 src->enc_context_owner = NULL;
1993 src->es_active = false;
1994
1995 list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list);
1996
1997 /*
1998 * If this VM has mirrors, "transfer" each mirror's refcount of the
1999 * source to the destination (this KVM). The caller holds a reference
2000 * to the source, so there's no danger of use-after-free.
2001 */
2002 list_cut_before(&dst->mirror_vms, &src->mirror_vms, &src->mirror_vms);
2003 list_for_each_entry(mirror, &dst->mirror_vms, mirror_entry) {
2004 kvm_get_kvm(dst_kvm);
2005 kvm_put_kvm(src_kvm);
2006 mirror->enc_context_owner = dst_kvm;
2007 }
2008
2009 /*
2010 * If this VM is a mirror, remove the old mirror from the owners list
2011 * and add the new mirror to the list.
2012 */
2013 if (is_mirroring_enc_context(dst_kvm)) {
2014 struct kvm_sev_info *owner_sev_info =
2015 &to_kvm_svm(dst->enc_context_owner)->sev_info;
2016
2017 list_del(&src->mirror_entry);
2018 list_add_tail(&dst->mirror_entry, &owner_sev_info->mirror_vms);
2019 }
2020
2021 kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) {
2022 dst_svm = to_svm(dst_vcpu);
2023
2024 sev_init_vmcb(dst_svm);
2025
2026 if (!dst->es_active)
2027 continue;
2028
2029 /*
2030 * Note, the source is not required to have the same number of
2031 * vCPUs as the destination when migrating a vanilla SEV VM.
2032 */
2033 src_vcpu = kvm_get_vcpu(src_kvm, i);
2034 src_svm = to_svm(src_vcpu);
2035
2036 /*
2037 * Transfer VMSA and GHCB state to the destination. Nullify and
2038 * clear source fields as appropriate, the state now belongs to
2039 * the destination.
2040 */
2041 memcpy(&dst_svm->sev_es, &src_svm->sev_es, sizeof(src_svm->sev_es));
2042 dst_svm->vmcb->control.ghcb_gpa = src_svm->vmcb->control.ghcb_gpa;
2043 dst_svm->vmcb->control.vmsa_pa = src_svm->vmcb->control.vmsa_pa;
2044 dst_vcpu->arch.guest_state_protected = true;
2045
2046 memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));
2047 src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;
2048 src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;
2049 src_vcpu->arch.guest_state_protected = false;
2050 }
2051 }
2052
2053 static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src)
2054 {
2055 struct kvm_vcpu *src_vcpu;
2056 unsigned long i;
2057
2058 if (!sev_es_guest(src))
2059 return 0;
2060
2061 if (atomic_read(&src->online_vcpus) != atomic_read(&dst->online_vcpus))
2062 return -EINVAL;
2063
2064 kvm_for_each_vcpu(i, src_vcpu, src) {
2065 if (!src_vcpu->arch.guest_state_protected)
2066 return -EINVAL;
2067 }
2068
2069 return 0;
2070 }
2071
2072 int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
2073 {
2074 struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info;
2075 struct kvm_sev_info *src_sev, *cg_cleanup_sev;
2076 struct fd f = fdget(source_fd);
2077 struct kvm *source_kvm;
2078 bool charged = false;
2079 int ret;
2080
2081 if (!f.file)
2082 return -EBADF;
2083
2084 if (!file_is_kvm(f.file)) {
2085 ret = -EBADF;
2086 goto out_fput;
2087 }
2088
2089 source_kvm = f.file->private_data;
2090 ret = sev_lock_two_vms(kvm, source_kvm);
2091 if (ret)
2092 goto out_fput;
2093
2094 if (kvm->arch.vm_type != source_kvm->arch.vm_type ||
2095 sev_guest(kvm) || !sev_guest(source_kvm)) {
2096 ret = -EINVAL;
2097 goto out_unlock;
2098 }
2099
2100 src_sev = &to_kvm_svm(source_kvm)->sev_info;
2101
2102 dst_sev->misc_cg = get_current_misc_cg();
2103 cg_cleanup_sev = dst_sev;
2104 if (dst_sev->misc_cg != src_sev->misc_cg) {
2105 ret = sev_misc_cg_try_charge(dst_sev);
2106 if (ret)
2107 goto out_dst_cgroup;
2108 charged = true;
2109 }
2110
2111 ret = sev_lock_vcpus_for_migration(kvm, SEV_MIGRATION_SOURCE);
2112 if (ret)
2113 goto out_dst_cgroup;
2114 ret = sev_lock_vcpus_for_migration(source_kvm, SEV_MIGRATION_TARGET);
2115 if (ret)
2116 goto out_dst_vcpu;
2117
2118 ret = sev_check_source_vcpus(kvm, source_kvm);
2119 if (ret)
2120 goto out_source_vcpu;
2121
2122 sev_migrate_from(kvm, source_kvm);
2123 kvm_vm_dead(source_kvm);
2124 cg_cleanup_sev = src_sev;
2125 ret = 0;
2126
2127 out_source_vcpu:
2128 sev_unlock_vcpus_for_migration(source_kvm);
2129 out_dst_vcpu:
2130 sev_unlock_vcpus_for_migration(kvm);
2131 out_dst_cgroup:
2132 /* Operates on the source on success, on the destination on failure. */
2133 if (charged)
2134 sev_misc_cg_uncharge(cg_cleanup_sev);
2135 put_misc_cg(cg_cleanup_sev->misc_cg);
2136 cg_cleanup_sev->misc_cg = NULL;
2137 out_unlock:
2138 sev_unlock_two_vms(kvm, source_kvm);
2139 out_fput:
2140 fdput(f);
2141 return ret;
2142 }
2143
2144 int sev_dev_get_attr(u32 group, u64 attr, u64 *val)
2145 {
2146 if (group != KVM_X86_GRP_SEV)
2147 return -ENXIO;
2148
2149 switch (attr) {
2150 case KVM_X86_SEV_VMSA_FEATURES:
2151 *val = sev_supported_vmsa_features;
2152 return 0;
2153
2154 default:
2155 return -ENXIO;
2156 }
2157 }
2158
2159 /*
2160 * The guest context contains all the information, keys and metadata
2161 * associated with the guest that the firmware tracks to implement SEV
2162 * and SNP features. The firmware stores the guest context in hypervisor
2163 * provide page via the SNP_GCTX_CREATE command.
2164 */
2165 static void *snp_context_create(struct kvm *kvm, struct kvm_sev_cmd *argp)
2166 {
2167 struct sev_data_snp_addr data = {};
2168 void *context;
2169 int rc;
2170
2171 /* Allocate memory for context page */
2172 context = snp_alloc_firmware_page(GFP_KERNEL_ACCOUNT);
2173 if (!context)
2174 return NULL;
2175
2176 data.address = __psp_pa(context);
2177 rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_GCTX_CREATE, &data, &argp->error);
2178 if (rc) {
2179 pr_warn("Failed to create SEV-SNP context, rc %d fw_error %d",
2180 rc, argp->error);
2181 snp_free_firmware_page(context);
2182 return NULL;
2183 }
2184
2185 return context;
2186 }
2187
2188 static int snp_bind_asid(struct kvm *kvm, int *error)
2189 {
2190 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2191 struct sev_data_snp_activate data = {0};
2192
2193 data.gctx_paddr = __psp_pa(sev->snp_context);
2194 data.asid = sev_get_asid(kvm);
2195 return sev_issue_cmd(kvm, SEV_CMD_SNP_ACTIVATE, &data, error);
2196 }
2197
2198 static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
2199 {
2200 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2201 struct sev_data_snp_launch_start start = {0};
2202 struct kvm_sev_snp_launch_start params;
2203 int rc;
2204
2205 if (!sev_snp_guest(kvm))
2206 return -ENOTTY;
2207
2208 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
2209 return -EFAULT;
2210
2211 /* Don't allow userspace to allocate memory for more than 1 SNP context. */
2212 if (sev->snp_context)
2213 return -EINVAL;
2214
2215 sev->snp_context = snp_context_create(kvm, argp);
2216 if (!sev->snp_context)
2217 return -ENOTTY;
2218
2219 if (params.flags)
2220 return -EINVAL;
2221
2222 if (params.policy & ~SNP_POLICY_MASK_VALID)
2223 return -EINVAL;
2224
2225 /* Check for policy bits that must be set */
2226 if (!(params.policy & SNP_POLICY_MASK_RSVD_MBO) ||
2227 !(params.policy & SNP_POLICY_MASK_SMT))
2228 return -EINVAL;
2229
2230 if (params.policy & SNP_POLICY_MASK_SINGLE_SOCKET)
2231 return -EINVAL;
2232
2233 start.gctx_paddr = __psp_pa(sev->snp_context);
2234 start.policy = params.policy;
2235 memcpy(start.gosvw, params.gosvw, sizeof(params.gosvw));
2236 rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_START, &start, &argp->error);
2237 if (rc) {
2238 pr_debug("%s: SEV_CMD_SNP_LAUNCH_START firmware command failed, rc %d\n",
2239 __func__, rc);
2240 goto e_free_context;
2241 }
2242
2243 sev->fd = argp->sev_fd;
2244 rc = snp_bind_asid(kvm, &argp->error);
2245 if (rc) {
2246 pr_debug("%s: Failed to bind ASID to SEV-SNP context, rc %d\n",
2247 __func__, rc);
2248 goto e_free_context;
2249 }
2250
2251 return 0;
2252
2253 e_free_context:
2254 snp_decommission_context(kvm);
2255
2256 return rc;
2257 }
2258
2259 struct sev_gmem_populate_args {
2260 __u8 type;
2261 int sev_fd;
2262 int fw_error;
2263 };
2264
2265 static int sev_gmem_post_populate(struct kvm *kvm, gfn_t gfn_start, kvm_pfn_t pfn,
2266 void __user *src, int order, void *opaque)
2267 {
2268 struct sev_gmem_populate_args *sev_populate_args = opaque;
2269 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2270 int n_private = 0, ret, i;
2271 int npages = (1 << order);
2272 gfn_t gfn;
2273
2274 if (WARN_ON_ONCE(sev_populate_args->type != KVM_SEV_SNP_PAGE_TYPE_ZERO && !src))
2275 return -EINVAL;
2276
2277 for (gfn = gfn_start, i = 0; gfn < gfn_start + npages; gfn++, i++) {
2278 struct sev_data_snp_launch_update fw_args = {0};
2279 bool assigned = false;
2280 int level;
2281
2282 ret = snp_lookup_rmpentry((u64)pfn + i, &assigned, &level);
2283 if (ret || assigned) {
2284 pr_debug("%s: Failed to ensure GFN 0x%llx RMP entry is initial shared state, ret: %d assigned: %d\n",
2285 __func__, gfn, ret, assigned);
2286 ret = ret ? -EINVAL : -EEXIST;
2287 goto err;
2288 }
2289
2290 if (src) {
2291 void *vaddr = kmap_local_pfn(pfn + i);
2292
2293 if (copy_from_user(vaddr, src + i * PAGE_SIZE, PAGE_SIZE)) {
2294 ret = -EFAULT;
2295 goto err;
2296 }
2297 kunmap_local(vaddr);
2298 }
2299
2300 ret = rmp_make_private(pfn + i, gfn << PAGE_SHIFT, PG_LEVEL_4K,
2301 sev_get_asid(kvm), true);
2302 if (ret)
2303 goto err;
2304
2305 n_private++;
2306
2307 fw_args.gctx_paddr = __psp_pa(sev->snp_context);
2308 fw_args.address = __sme_set(pfn_to_hpa(pfn + i));
2309 fw_args.page_size = PG_LEVEL_TO_RMP(PG_LEVEL_4K);
2310 fw_args.page_type = sev_populate_args->type;
2311
2312 ret = __sev_issue_cmd(sev_populate_args->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE,
2313 &fw_args, &sev_populate_args->fw_error);
2314 if (ret)
2315 goto fw_err;
2316 }
2317
2318 return 0;
2319
2320 fw_err:
2321 /*
2322 * If the firmware command failed handle the reclaim and cleanup of that
2323 * PFN specially vs. prior pages which can be cleaned up below without
2324 * needing to reclaim in advance.
2325 *
2326 * Additionally, when invalid CPUID function entries are detected,
2327 * firmware writes the expected values into the page and leaves it
2328 * unencrypted so it can be used for debugging and error-reporting.
2329 *
2330 * Copy this page back into the source buffer so userspace can use this
2331 * information to provide information on which CPUID leaves/fields
2332 * failed CPUID validation.
2333 */
2334 if (!snp_page_reclaim(kvm, pfn + i) &&
2335 sev_populate_args->type == KVM_SEV_SNP_PAGE_TYPE_CPUID &&
2336 sev_populate_args->fw_error == SEV_RET_INVALID_PARAM) {
2337 void *vaddr = kmap_local_pfn(pfn + i);
2338
2339 if (copy_to_user(src + i * PAGE_SIZE, vaddr, PAGE_SIZE))
2340 pr_debug("Failed to write CPUID page back to userspace\n");
2341
2342 kunmap_local(vaddr);
2343 }
2344
2345 /* pfn + i is hypervisor-owned now, so skip below cleanup for it. */
2346 n_private--;
2347
2348 err:
2349 pr_debug("%s: exiting with error ret %d (fw_error %d), restoring %d gmem PFNs to shared.\n",
2350 __func__, ret, sev_populate_args->fw_error, n_private);
2351 for (i = 0; i < n_private; i++)
2352 kvm_rmp_make_shared(kvm, pfn + i, PG_LEVEL_4K);
2353
2354 return ret;
2355 }
2356
2357 static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp)
2358 {
2359 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2360 struct sev_gmem_populate_args sev_populate_args = {0};
2361 struct kvm_sev_snp_launch_update params;
2362 struct kvm_memory_slot *memslot;
2363 long npages, count;
2364 void __user *src;
2365 int ret = 0;
2366
2367 if (!sev_snp_guest(kvm) || !sev->snp_context)
2368 return -EINVAL;
2369
2370 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
2371 return -EFAULT;
2372
2373 pr_debug("%s: GFN start 0x%llx length 0x%llx type %d flags %d\n", __func__,
2374 params.gfn_start, params.len, params.type, params.flags);
2375
2376 if (!PAGE_ALIGNED(params.len) || params.flags ||
2377 (params.type != KVM_SEV_SNP_PAGE_TYPE_NORMAL &&
2378 params.type != KVM_SEV_SNP_PAGE_TYPE_ZERO &&
2379 params.type != KVM_SEV_SNP_PAGE_TYPE_UNMEASURED &&
2380 params.type != KVM_SEV_SNP_PAGE_TYPE_SECRETS &&
2381 params.type != KVM_SEV_SNP_PAGE_TYPE_CPUID))
2382 return -EINVAL;
2383
2384 npages = params.len / PAGE_SIZE;
2385
2386 /*
2387 * For each GFN that's being prepared as part of the initial guest
2388 * state, the following pre-conditions are verified:
2389 *
2390 * 1) The backing memslot is a valid private memslot.
2391 * 2) The GFN has been set to private via KVM_SET_MEMORY_ATTRIBUTES
2392 * beforehand.
2393 * 3) The PFN of the guest_memfd has not already been set to private
2394 * in the RMP table.
2395 *
2396 * The KVM MMU relies on kvm->mmu_invalidate_seq to retry nested page
2397 * faults if there's a race between a fault and an attribute update via
2398 * KVM_SET_MEMORY_ATTRIBUTES, and a similar approach could be utilized
2399 * here. However, kvm->slots_lock guards against both this as well as
2400 * concurrent memslot updates occurring while these checks are being
2401 * performed, so use that here to make it easier to reason about the
2402 * initial expected state and better guard against unexpected
2403 * situations.
2404 */
2405 mutex_lock(&kvm->slots_lock);
2406
2407 memslot = gfn_to_memslot(kvm, params.gfn_start);
2408 if (!kvm_slot_can_be_private(memslot)) {
2409 ret = -EINVAL;
2410 goto out;
2411 }
2412
2413 sev_populate_args.sev_fd = argp->sev_fd;
2414 sev_populate_args.type = params.type;
2415 src = params.type == KVM_SEV_SNP_PAGE_TYPE_ZERO ? NULL : u64_to_user_ptr(params.uaddr);
2416
2417 count = kvm_gmem_populate(kvm, params.gfn_start, src, npages,
2418 sev_gmem_post_populate, &sev_populate_args);
2419 if (count < 0) {
2420 argp->error = sev_populate_args.fw_error;
2421 pr_debug("%s: kvm_gmem_populate failed, ret %ld (fw_error %d)\n",
2422 __func__, count, argp->error);
2423 ret = -EIO;
2424 } else {
2425 params.gfn_start += count;
2426 params.len -= count * PAGE_SIZE;
2427 if (params.type != KVM_SEV_SNP_PAGE_TYPE_ZERO)
2428 params.uaddr += count * PAGE_SIZE;
2429
2430 ret = 0;
2431 if (copy_to_user(u64_to_user_ptr(argp->data), ¶ms, sizeof(params)))
2432 ret = -EFAULT;
2433 }
2434
2435 out:
2436 mutex_unlock(&kvm->slots_lock);
2437
2438 return ret;
2439 }
2440
2441 static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
2442 {
2443 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2444 struct sev_data_snp_launch_update data = {};
2445 struct kvm_vcpu *vcpu;
2446 unsigned long i;
2447 int ret;
2448
2449 data.gctx_paddr = __psp_pa(sev->snp_context);
2450 data.page_type = SNP_PAGE_TYPE_VMSA;
2451
2452 kvm_for_each_vcpu(i, vcpu, kvm) {
2453 struct vcpu_svm *svm = to_svm(vcpu);
2454 u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT;
2455
2456 ret = sev_es_sync_vmsa(svm);
2457 if (ret)
2458 return ret;
2459
2460 /* Transition the VMSA page to a firmware state. */
2461 ret = rmp_make_private(pfn, INITIAL_VMSA_GPA, PG_LEVEL_4K, sev->asid, true);
2462 if (ret)
2463 return ret;
2464
2465 /* Issue the SNP command to encrypt the VMSA */
2466 data.address = __sme_pa(svm->sev_es.vmsa);
2467 ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_UPDATE,
2468 &data, &argp->error);
2469 if (ret) {
2470 snp_page_reclaim(kvm, pfn);
2471
2472 return ret;
2473 }
2474
2475 svm->vcpu.arch.guest_state_protected = true;
2476 /*
2477 * SEV-ES (and thus SNP) guest mandates LBR Virtualization to
2478 * be _always_ ON. Enable it only after setting
2479 * guest_state_protected because KVM_SET_MSRS allows dynamic
2480 * toggling of LBRV (for performance reason) on write access to
2481 * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.
2482 */
2483 svm_enable_lbrv(vcpu);
2484 }
2485
2486 return 0;
2487 }
2488
2489 static int snp_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
2490 {
2491 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2492 struct kvm_sev_snp_launch_finish params;
2493 struct sev_data_snp_launch_finish *data;
2494 void *id_block = NULL, *id_auth = NULL;
2495 int ret;
2496
2497 if (!sev_snp_guest(kvm))
2498 return -ENOTTY;
2499
2500 if (!sev->snp_context)
2501 return -EINVAL;
2502
2503 if (copy_from_user(¶ms, u64_to_user_ptr(argp->data), sizeof(params)))
2504 return -EFAULT;
2505
2506 if (params.flags)
2507 return -EINVAL;
2508
2509 /* Measure all vCPUs using LAUNCH_UPDATE before finalizing the launch flow. */
2510 ret = snp_launch_update_vmsa(kvm, argp);
2511 if (ret)
2512 return ret;
2513
2514 data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
2515 if (!data)
2516 return -ENOMEM;
2517
2518 if (params.id_block_en) {
2519 id_block = psp_copy_user_blob(params.id_block_uaddr, KVM_SEV_SNP_ID_BLOCK_SIZE);
2520 if (IS_ERR(id_block)) {
2521 ret = PTR_ERR(id_block);
2522 goto e_free;
2523 }
2524
2525 data->id_block_en = 1;
2526 data->id_block_paddr = __sme_pa(id_block);
2527
2528 id_auth = psp_copy_user_blob(params.id_auth_uaddr, KVM_SEV_SNP_ID_AUTH_SIZE);
2529 if (IS_ERR(id_auth)) {
2530 ret = PTR_ERR(id_auth);
2531 goto e_free_id_block;
2532 }
2533
2534 data->id_auth_paddr = __sme_pa(id_auth);
2535
2536 if (params.auth_key_en)
2537 data->auth_key_en = 1;
2538 }
2539
2540 data->vcek_disabled = params.vcek_disabled;
2541
2542 memcpy(data->host_data, params.host_data, KVM_SEV_SNP_FINISH_DATA_SIZE);
2543 data->gctx_paddr = __psp_pa(sev->snp_context);
2544 ret = sev_issue_cmd(kvm, SEV_CMD_SNP_LAUNCH_FINISH, data, &argp->error);
2545
2546 /*
2547 * Now that there will be no more SNP_LAUNCH_UPDATE ioctls, private pages
2548 * can be given to the guest simply by marking the RMP entry as private.
2549 * This can happen on first access and also with KVM_PRE_FAULT_MEMORY.
2550 */
2551 if (!ret)
2552 kvm->arch.pre_fault_allowed = true;
2553
2554 kfree(id_auth);
2555
2556 e_free_id_block:
2557 kfree(id_block);
2558
2559 e_free:
2560 kfree(data);
2561
2562 return ret;
2563 }
2564
2565 int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
2566 {
2567 struct kvm_sev_cmd sev_cmd;
2568 int r;
2569
2570 if (!sev_enabled)
2571 return -ENOTTY;
2572
2573 if (!argp)
2574 return 0;
2575
2576 if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
2577 return -EFAULT;
2578
2579 mutex_lock(&kvm->lock);
2580
2581 /* Only the enc_context_owner handles some memory enc operations. */
2582 if (is_mirroring_enc_context(kvm) &&
2583 !is_cmd_allowed_from_mirror(sev_cmd.id)) {
2584 r = -EINVAL;
2585 goto out;
2586 }
2587
2588 /*
2589 * Once KVM_SEV_INIT2 initializes a KVM instance as an SNP guest, only
2590 * allow the use of SNP-specific commands.
2591 */
2592 if (sev_snp_guest(kvm) && sev_cmd.id < KVM_SEV_SNP_LAUNCH_START) {
2593 r = -EPERM;
2594 goto out;
2595 }
2596
2597 switch (sev_cmd.id) {
2598 case KVM_SEV_ES_INIT:
2599 if (!sev_es_enabled) {
2600 r = -ENOTTY;
2601 goto out;
2602 }
2603 fallthrough;
2604 case KVM_SEV_INIT:
2605 r = sev_guest_init(kvm, &sev_cmd);
2606 break;
2607 case KVM_SEV_INIT2:
2608 r = sev_guest_init2(kvm, &sev_cmd);
2609 break;
2610 case KVM_SEV_LAUNCH_START:
2611 r = sev_launch_start(kvm, &sev_cmd);
2612 break;
2613 case KVM_SEV_LAUNCH_UPDATE_DATA:
2614 r = sev_launch_update_data(kvm, &sev_cmd);
2615 break;
2616 case KVM_SEV_LAUNCH_UPDATE_VMSA:
2617 r = sev_launch_update_vmsa(kvm, &sev_cmd);
2618 break;
2619 case KVM_SEV_LAUNCH_MEASURE:
2620 r = sev_launch_measure(kvm, &sev_cmd);
2621 break;
2622 case KVM_SEV_LAUNCH_FINISH:
2623 r = sev_launch_finish(kvm, &sev_cmd);
2624 break;
2625 case KVM_SEV_GUEST_STATUS:
2626 r = sev_guest_status(kvm, &sev_cmd);
2627 break;
2628 case KVM_SEV_DBG_DECRYPT:
2629 r = sev_dbg_crypt(kvm, &sev_cmd, true);
2630 break;
2631 case KVM_SEV_DBG_ENCRYPT:
2632 r = sev_dbg_crypt(kvm, &sev_cmd, false);
2633 break;
2634 case KVM_SEV_LAUNCH_SECRET:
2635 r = sev_launch_secret(kvm, &sev_cmd);
2636 break;
2637 case KVM_SEV_GET_ATTESTATION_REPORT:
2638 r = sev_get_attestation_report(kvm, &sev_cmd);
2639 break;
2640 case KVM_SEV_SEND_START:
2641 r = sev_send_start(kvm, &sev_cmd);
2642 break;
2643 case KVM_SEV_SEND_UPDATE_DATA:
2644 r = sev_send_update_data(kvm, &sev_cmd);
2645 break;
2646 case KVM_SEV_SEND_FINISH:
2647 r = sev_send_finish(kvm, &sev_cmd);
2648 break;
2649 case KVM_SEV_SEND_CANCEL:
2650 r = sev_send_cancel(kvm, &sev_cmd);
2651 break;
2652 case KVM_SEV_RECEIVE_START:
2653 r = sev_receive_start(kvm, &sev_cmd);
2654 break;
2655 case KVM_SEV_RECEIVE_UPDATE_DATA:
2656 r = sev_receive_update_data(kvm, &sev_cmd);
2657 break;
2658 case KVM_SEV_RECEIVE_FINISH:
2659 r = sev_receive_finish(kvm, &sev_cmd);
2660 break;
2661 case KVM_SEV_SNP_LAUNCH_START:
2662 r = snp_launch_start(kvm, &sev_cmd);
2663 break;
2664 case KVM_SEV_SNP_LAUNCH_UPDATE:
2665 r = snp_launch_update(kvm, &sev_cmd);
2666 break;
2667 case KVM_SEV_SNP_LAUNCH_FINISH:
2668 r = snp_launch_finish(kvm, &sev_cmd);
2669 break;
2670 default:
2671 r = -EINVAL;
2672 goto out;
2673 }
2674
2675 if (copy_to_user(argp, &sev_cmd, sizeof(struct kvm_sev_cmd)))
2676 r = -EFAULT;
2677
2678 out:
2679 mutex_unlock(&kvm->lock);
2680 return r;
2681 }
2682
2683 int sev_mem_enc_register_region(struct kvm *kvm,
2684 struct kvm_enc_region *range)
2685 {
2686 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2687 struct enc_region *region;
2688 int ret = 0;
2689
2690 if (!sev_guest(kvm))
2691 return -ENOTTY;
2692
2693 /* If kvm is mirroring encryption context it isn't responsible for it */
2694 if (is_mirroring_enc_context(kvm))
2695 return -EINVAL;
2696
2697 if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
2698 return -EINVAL;
2699
2700 region = kzalloc(sizeof(*region), GFP_KERNEL_ACCOUNT);
2701 if (!region)
2702 return -ENOMEM;
2703
2704 mutex_lock(&kvm->lock);
2705 region->pages = sev_pin_memory(kvm, range->addr, range->size, ®ion->npages, 1);
2706 if (IS_ERR(region->pages)) {
2707 ret = PTR_ERR(region->pages);
2708 mutex_unlock(&kvm->lock);
2709 goto e_free;
2710 }
2711
2712 /*
2713 * The guest may change the memory encryption attribute from C=0 -> C=1
2714 * or vice versa for this memory range. Lets make sure caches are
2715 * flushed to ensure that guest data gets written into memory with
2716 * correct C-bit. Note, this must be done before dropping kvm->lock,
2717 * as region and its array of pages can be freed by a different task
2718 * once kvm->lock is released.
2719 */
2720 sev_clflush_pages(region->pages, region->npages);
2721
2722 region->uaddr = range->addr;
2723 region->size = range->size;
2724
2725 list_add_tail(®ion->list, &sev->regions_list);
2726 mutex_unlock(&kvm->lock);
2727
2728 return ret;
2729
2730 e_free:
2731 kfree(region);
2732 return ret;
2733 }
2734
2735 static struct enc_region *
2736 find_enc_region(struct kvm *kvm, struct kvm_enc_region *range)
2737 {
2738 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2739 struct list_head *head = &sev->regions_list;
2740 struct enc_region *i;
2741
2742 list_for_each_entry(i, head, list) {
2743 if (i->uaddr == range->addr &&
2744 i->size == range->size)
2745 return i;
2746 }
2747
2748 return NULL;
2749 }
2750
2751 static void __unregister_enc_region_locked(struct kvm *kvm,
2752 struct enc_region *region)
2753 {
2754 sev_unpin_memory(kvm, region->pages, region->npages);
2755 list_del(®ion->list);
2756 kfree(region);
2757 }
2758
2759 int sev_mem_enc_unregister_region(struct kvm *kvm,
2760 struct kvm_enc_region *range)
2761 {
2762 struct enc_region *region;
2763 int ret;
2764
2765 /* If kvm is mirroring encryption context it isn't responsible for it */
2766 if (is_mirroring_enc_context(kvm))
2767 return -EINVAL;
2768
2769 mutex_lock(&kvm->lock);
2770
2771 if (!sev_guest(kvm)) {
2772 ret = -ENOTTY;
2773 goto failed;
2774 }
2775
2776 region = find_enc_region(kvm, range);
2777 if (!region) {
2778 ret = -EINVAL;
2779 goto failed;
2780 }
2781
2782 /*
2783 * Ensure that all guest tagged cache entries are flushed before
2784 * releasing the pages back to the system for use. CLFLUSH will
2785 * not do this, so issue a WBINVD.
2786 */
2787 wbinvd_on_all_cpus();
2788
2789 __unregister_enc_region_locked(kvm, region);
2790
2791 mutex_unlock(&kvm->lock);
2792 return 0;
2793
2794 failed:
2795 mutex_unlock(&kvm->lock);
2796 return ret;
2797 }
2798
2799 int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
2800 {
2801 struct fd f = fdget(source_fd);
2802 struct kvm *source_kvm;
2803 struct kvm_sev_info *source_sev, *mirror_sev;
2804 int ret;
2805
2806 if (!f.file)
2807 return -EBADF;
2808
2809 if (!file_is_kvm(f.file)) {
2810 ret = -EBADF;
2811 goto e_source_fput;
2812 }
2813
2814 source_kvm = f.file->private_data;
2815 ret = sev_lock_two_vms(kvm, source_kvm);
2816 if (ret)
2817 goto e_source_fput;
2818
2819 /*
2820 * Mirrors of mirrors should work, but let's not get silly. Also
2821 * disallow out-of-band SEV/SEV-ES init if the target is already an
2822 * SEV guest, or if vCPUs have been created. KVM relies on vCPUs being
2823 * created after SEV/SEV-ES initialization, e.g. to init intercepts.
2824 */
2825 if (sev_guest(kvm) || !sev_guest(source_kvm) ||
2826 is_mirroring_enc_context(source_kvm) || kvm->created_vcpus) {
2827 ret = -EINVAL;
2828 goto e_unlock;
2829 }
2830
2831 /*
2832 * The mirror kvm holds an enc_context_owner ref so its asid can't
2833 * disappear until we're done with it
2834 */
2835 source_sev = &to_kvm_svm(source_kvm)->sev_info;
2836 kvm_get_kvm(source_kvm);
2837 mirror_sev = &to_kvm_svm(kvm)->sev_info;
2838 list_add_tail(&mirror_sev->mirror_entry, &source_sev->mirror_vms);
2839
2840 /* Set enc_context_owner and copy its encryption context over */
2841 mirror_sev->enc_context_owner = source_kvm;
2842 mirror_sev->active = true;
2843 mirror_sev->asid = source_sev->asid;
2844 mirror_sev->fd = source_sev->fd;
2845 mirror_sev->es_active = source_sev->es_active;
2846 mirror_sev->need_init = false;
2847 mirror_sev->handle = source_sev->handle;
2848 INIT_LIST_HEAD(&mirror_sev->regions_list);
2849 INIT_LIST_HEAD(&mirror_sev->mirror_vms);
2850 ret = 0;
2851
2852 /*
2853 * Do not copy ap_jump_table. Since the mirror does not share the same
2854 * KVM contexts as the original, and they may have different
2855 * memory-views.
2856 */
2857
2858 e_unlock:
2859 sev_unlock_two_vms(kvm, source_kvm);
2860 e_source_fput:
2861 fdput(f);
2862 return ret;
2863 }
2864
2865 static int snp_decommission_context(struct kvm *kvm)
2866 {
2867 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2868 struct sev_data_snp_addr data = {};
2869 int ret;
2870
2871 /* If context is not created then do nothing */
2872 if (!sev->snp_context)
2873 return 0;
2874
2875 /* Do the decommision, which will unbind the ASID from the SNP context */
2876 data.address = __sme_pa(sev->snp_context);
2877 down_write(&sev_deactivate_lock);
2878 ret = sev_do_cmd(SEV_CMD_SNP_DECOMMISSION, &data, NULL);
2879 up_write(&sev_deactivate_lock);
2880
2881 if (WARN_ONCE(ret, "Failed to release guest context, ret %d", ret))
2882 return ret;
2883
2884 snp_free_firmware_page(sev->snp_context);
2885 sev->snp_context = NULL;
2886
2887 return 0;
2888 }
2889
2890 void sev_vm_destroy(struct kvm *kvm)
2891 {
2892 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
2893 struct list_head *head = &sev->regions_list;
2894 struct list_head *pos, *q;
2895
2896 if (!sev_guest(kvm))
2897 return;
2898
2899 WARN_ON(!list_empty(&sev->mirror_vms));
2900
2901 /* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */
2902 if (is_mirroring_enc_context(kvm)) {
2903 struct kvm *owner_kvm = sev->enc_context_owner;
2904
2905 mutex_lock(&owner_kvm->lock);
2906 list_del(&sev->mirror_entry);
2907 mutex_unlock(&owner_kvm->lock);
2908 kvm_put_kvm(owner_kvm);
2909 return;
2910 }
2911
2912 /*
2913 * Ensure that all guest tagged cache entries are flushed before
2914 * releasing the pages back to the system for use. CLFLUSH will
2915 * not do this, so issue a WBINVD.
2916 */
2917 wbinvd_on_all_cpus();
2918
2919 /*
2920 * if userspace was terminated before unregistering the memory regions
2921 * then lets unpin all the registered memory.
2922 */
2923 if (!list_empty(head)) {
2924 list_for_each_safe(pos, q, head) {
2925 __unregister_enc_region_locked(kvm,
2926 list_entry(pos, struct enc_region, list));
2927 cond_resched();
2928 }
2929 }
2930
2931 if (sev_snp_guest(kvm)) {
2932 snp_guest_req_cleanup(kvm);
2933
2934 /*
2935 * Decomission handles unbinding of the ASID. If it fails for
2936 * some unexpected reason, just leak the ASID.
2937 */
2938 if (snp_decommission_context(kvm))
2939 return;
2940 } else {
2941 sev_unbind_asid(kvm, sev->handle);
2942 }
2943
2944 sev_asid_free(sev);
2945 }
2946
2947 void __init sev_set_cpu_caps(void)
2948 {
2949 if (sev_enabled) {
2950 kvm_cpu_cap_set(X86_FEATURE_SEV);
2951 kvm_caps.supported_vm_types |= BIT(KVM_X86_SEV_VM);
2952 }
2953 if (sev_es_enabled) {
2954 kvm_cpu_cap_set(X86_FEATURE_SEV_ES);
2955 kvm_caps.supported_vm_types |= BIT(KVM_X86_SEV_ES_VM);
2956 }
2957 if (sev_snp_enabled) {
2958 kvm_cpu_cap_set(X86_FEATURE_SEV_SNP);
2959 kvm_caps.supported_vm_types |= BIT(KVM_X86_SNP_VM);
2960 }
2961 }
2962
2963 void __init sev_hardware_setup(void)
2964 {
2965 unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
2966 bool sev_snp_supported = false;
2967 bool sev_es_supported = false;
2968 bool sev_supported = false;
2969
2970 if (!sev_enabled || !npt_enabled || !nrips)
2971 goto out;
2972
2973 /*
2974 * SEV must obviously be supported in hardware. Sanity check that the
2975 * CPU supports decode assists, which is mandatory for SEV guests to
2976 * support instruction emulation. Ditto for flushing by ASID, as SEV
2977 * guests are bound to a single ASID, i.e. KVM can't rotate to a new
2978 * ASID to effect a TLB flush.
2979 */
2980 if (!boot_cpu_has(X86_FEATURE_SEV) ||
2981 WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)) ||
2982 WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_FLUSHBYASID)))
2983 goto out;
2984
2985 /* Retrieve SEV CPUID information */
2986 cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);
2987
2988 /* Set encryption bit location for SEV-ES guests */
2989 sev_enc_bit = ebx & 0x3f;
2990
2991 /* Maximum number of encrypted guests supported simultaneously */
2992 max_sev_asid = ecx;
2993 if (!max_sev_asid)
2994 goto out;
2995
2996 /* Minimum ASID value that should be used for SEV guest */
2997 min_sev_asid = edx;
2998 sev_me_mask = 1UL << (ebx & 0x3f);
2999
3000 /*
3001 * Initialize SEV ASID bitmaps. Allocate space for ASID 0 in the bitmap,
3002 * even though it's never used, so that the bitmap is indexed by the
3003 * actual ASID.
3004 */
3005 nr_asids = max_sev_asid + 1;
3006 sev_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
3007 if (!sev_asid_bitmap)
3008 goto out;
3009
3010 sev_reclaim_asid_bitmap = bitmap_zalloc(nr_asids, GFP_KERNEL);
3011 if (!sev_reclaim_asid_bitmap) {
3012 bitmap_free(sev_asid_bitmap);
3013 sev_asid_bitmap = NULL;
3014 goto out;
3015 }
3016
3017 if (min_sev_asid <= max_sev_asid) {
3018 sev_asid_count = max_sev_asid - min_sev_asid + 1;
3019 WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count));
3020 }
3021 sev_supported = true;
3022
3023 /* SEV-ES support requested? */
3024 if (!sev_es_enabled)
3025 goto out;
3026
3027 /*
3028 * SEV-ES requires MMIO caching as KVM doesn't have access to the guest
3029 * instruction stream, i.e. can't emulate in response to a #NPF and
3030 * instead relies on #NPF(RSVD) being reflected into the guest as #VC
3031 * (the guest can then do a #VMGEXIT to request MMIO emulation).
3032 */
3033 if (!enable_mmio_caching)
3034 goto out;
3035
3036 /* Does the CPU support SEV-ES? */
3037 if (!boot_cpu_has(X86_FEATURE_SEV_ES))
3038 goto out;
3039
3040 if (!lbrv) {
3041 WARN_ONCE(!boot_cpu_has(X86_FEATURE_LBRV),
3042 "LBRV must be present for SEV-ES support");
3043 goto out;
3044 }
3045
3046 /* Has the system been allocated ASIDs for SEV-ES? */
3047 if (min_sev_asid == 1)
3048 goto out;
3049
3050 sev_es_asid_count = min_sev_asid - 1;
3051 WARN_ON_ONCE(misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count));
3052 sev_es_supported = true;
3053 sev_snp_supported = sev_snp_enabled && cc_platform_has(CC_ATTR_HOST_SEV_SNP);
3054
3055 out:
3056 if (boot_cpu_has(X86_FEATURE_SEV))
3057 pr_info("SEV %s (ASIDs %u - %u)\n",
3058 sev_supported ? min_sev_asid <= max_sev_asid ? "enabled" :
3059 "unusable" :
3060 "disabled",
3061 min_sev_asid, max_sev_asid);
3062 if (boot_cpu_has(X86_FEATURE_SEV_ES))
3063 pr_info("SEV-ES %s (ASIDs %u - %u)\n",
3064 sev_es_supported ? "enabled" : "disabled",
3065 min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
3066 if (boot_cpu_has(X86_FEATURE_SEV_SNP))
3067 pr_info("SEV-SNP %s (ASIDs %u - %u)\n",
3068 sev_snp_supported ? "enabled" : "disabled",
3069 min_sev_asid > 1 ? 1 : 0, min_sev_asid - 1);
3070
3071 sev_enabled = sev_supported;
3072 sev_es_enabled = sev_es_supported;
3073 sev_snp_enabled = sev_snp_supported;
3074
3075 if (!sev_es_enabled || !cpu_feature_enabled(X86_FEATURE_DEBUG_SWAP) ||
3076 !cpu_feature_enabled(X86_FEATURE_NO_NESTED_DATA_BP))
3077 sev_es_debug_swap_enabled = false;
3078
3079 sev_supported_vmsa_features = 0;
3080 if (sev_es_debug_swap_enabled)
3081 sev_supported_vmsa_features |= SVM_SEV_FEAT_DEBUG_SWAP;
3082 }
3083
3084 void sev_hardware_unsetup(void)
3085 {
3086 if (!sev_enabled)
3087 return;
3088
3089 /* No need to take sev_bitmap_lock, all VMs have been destroyed. */
3090 sev_flush_asids(1, max_sev_asid);
3091
3092 bitmap_free(sev_asid_bitmap);
3093 bitmap_free(sev_reclaim_asid_bitmap);
3094
3095 misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
3096 misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
3097 }
3098
3099 int sev_cpu_init(struct svm_cpu_data *sd)
3100 {
3101 if (!sev_enabled)
3102 return 0;
3103
3104 sd->sev_vmcbs = kcalloc(nr_asids, sizeof(void *), GFP_KERNEL);
3105 if (!sd->sev_vmcbs)
3106 return -ENOMEM;
3107
3108 return 0;
3109 }
3110
3111 /*
3112 * Pages used by hardware to hold guest encrypted state must be flushed before
3113 * returning them to the system.
3114 */
3115 static void sev_flush_encrypted_page(struct kvm_vcpu *vcpu, void *va)
3116 {
3117 unsigned int asid = sev_get_asid(vcpu->kvm);
3118
3119 /*
3120 * Note! The address must be a kernel address, as regular page walk
3121 * checks are performed by VM_PAGE_FLUSH, i.e. operating on a user
3122 * address is non-deterministic and unsafe. This function deliberately
3123 * takes a pointer to deter passing in a user address.
3124 */
3125 unsigned long addr = (unsigned long)va;
3126
3127 /*
3128 * If CPU enforced cache coherency for encrypted mappings of the
3129 * same physical page is supported, use CLFLUSHOPT instead. NOTE: cache
3130 * flush is still needed in order to work properly with DMA devices.
3131 */
3132 if (boot_cpu_has(X86_FEATURE_SME_COHERENT)) {
3133 clflush_cache_range(va, PAGE_SIZE);
3134 return;
3135 }
3136
3137 /*
3138 * VM Page Flush takes a host virtual address and a guest ASID. Fall
3139 * back to WBINVD if this faults so as not to make any problems worse
3140 * by leaving stale encrypted data in the cache.
3141 */
3142 if (WARN_ON_ONCE(wrmsrl_safe(MSR_AMD64_VM_PAGE_FLUSH, addr | asid)))
3143 goto do_wbinvd;
3144
3145 return;
3146
3147 do_wbinvd:
3148 wbinvd_on_all_cpus();
3149 }
3150
3151 void sev_guest_memory_reclaimed(struct kvm *kvm)
3152 {
3153 /*
3154 * With SNP+gmem, private/encrypted memory is unreachable via the
3155 * hva-based mmu notifiers, so these events are only actually
3156 * pertaining to shared pages where there is no need to perform
3157 * the WBINVD to flush associated caches.
3158 */
3159 if (!sev_guest(kvm) || sev_snp_guest(kvm))
3160 return;
3161
3162 wbinvd_on_all_cpus();
3163 }
3164
3165 void sev_free_vcpu(struct kvm_vcpu *vcpu)
3166 {
3167 struct vcpu_svm *svm;
3168
3169 if (!sev_es_guest(vcpu->kvm))
3170 return;
3171
3172 svm = to_svm(vcpu);
3173
3174 /*
3175 * If it's an SNP guest, then the VMSA was marked in the RMP table as
3176 * a guest-owned page. Transition the page to hypervisor state before
3177 * releasing it back to the system.
3178 */
3179 if (sev_snp_guest(vcpu->kvm)) {
3180 u64 pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT;
3181
3182 if (kvm_rmp_make_shared(vcpu->kvm, pfn, PG_LEVEL_4K))
3183 goto skip_vmsa_free;
3184 }
3185
3186 if (vcpu->arch.guest_state_protected)
3187 sev_flush_encrypted_page(vcpu, svm->sev_es.vmsa);
3188
3189 __free_page(virt_to_page(svm->sev_es.vmsa));
3190
3191 skip_vmsa_free:
3192 if (svm->sev_es.ghcb_sa_free)
3193 kvfree(svm->sev_es.ghcb_sa);
3194 }
3195
3196 static void dump_ghcb(struct vcpu_svm *svm)
3197 {
3198 struct ghcb *ghcb = svm->sev_es.ghcb;
3199 unsigned int nbits;
3200
3201 /* Re-use the dump_invalid_vmcb module parameter */
3202 if (!dump_invalid_vmcb) {
3203 pr_warn_ratelimited("set kvm_amd.dump_invalid_vmcb=1 to dump internal KVM state.\n");
3204 return;
3205 }
3206
3207 nbits = sizeof(ghcb->save.valid_bitmap) * 8;
3208
3209 pr_err("GHCB (GPA=%016llx):\n", svm->vmcb->control.ghcb_gpa);
3210 pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_code",
3211 ghcb->save.sw_exit_code, ghcb_sw_exit_code_is_valid(ghcb));
3212 pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_1",
3213 ghcb->save.sw_exit_info_1, ghcb_sw_exit_info_1_is_valid(ghcb));
3214 pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_2",
3215 ghcb->save.sw_exit_info_2, ghcb_sw_exit_info_2_is_valid(ghcb));
3216 pr_err("%-20s%016llx is_valid: %u\n", "sw_scratch",
3217 ghcb->save.sw_scratch, ghcb_sw_scratch_is_valid(ghcb));
3218 pr_err("%-20s%*pb\n", "valid_bitmap", nbits, ghcb->save.valid_bitmap);
3219 }
3220
3221 static void sev_es_sync_to_ghcb(struct vcpu_svm *svm)
3222 {
3223 struct kvm_vcpu *vcpu = &svm->vcpu;
3224 struct ghcb *ghcb = svm->sev_es.ghcb;
3225
3226 /*
3227 * The GHCB protocol so far allows for the following data
3228 * to be returned:
3229 * GPRs RAX, RBX, RCX, RDX
3230 *
3231 * Copy their values, even if they may not have been written during the
3232 * VM-Exit. It's the guest's responsibility to not consume random data.
3233 */
3234 ghcb_set_rax(ghcb, vcpu->arch.regs[VCPU_REGS_RAX]);
3235 ghcb_set_rbx(ghcb, vcpu->arch.regs[VCPU_REGS_RBX]);
3236 ghcb_set_rcx(ghcb, vcpu->arch.regs[VCPU_REGS_RCX]);
3237 ghcb_set_rdx(ghcb, vcpu->arch.regs[VCPU_REGS_RDX]);
3238 }
3239
3240 static void sev_es_sync_from_ghcb(struct vcpu_svm *svm)
3241 {
3242 struct vmcb_control_area *control = &svm->vmcb->control;
3243 struct kvm_vcpu *vcpu = &svm->vcpu;
3244 struct ghcb *ghcb = svm->sev_es.ghcb;
3245 u64 exit_code;
3246
3247 /*
3248 * The GHCB protocol so far allows for the following data
3249 * to be supplied:
3250 * GPRs RAX, RBX, RCX, RDX
3251 * XCR0
3252 * CPL
3253 *
3254 * VMMCALL allows the guest to provide extra registers. KVM also
3255 * expects RSI for hypercalls, so include that, too.
3256 *
3257 * Copy their values to the appropriate location if supplied.
3258 */
3259 memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
3260
3261 BUILD_BUG_ON(sizeof(svm->sev_es.valid_bitmap) != sizeof(ghcb->save.valid_bitmap));
3262 memcpy(&svm->sev_es.valid_bitmap, &ghcb->save.valid_bitmap, sizeof(ghcb->save.valid_bitmap));
3263
3264 vcpu->arch.regs[VCPU_REGS_RAX] = kvm_ghcb_get_rax_if_valid(svm, ghcb);
3265 vcpu->arch.regs[VCPU_REGS_RBX] = kvm_ghcb_get_rbx_if_valid(svm, ghcb);
3266 vcpu->arch.regs[VCPU_REGS_RCX] = kvm_ghcb_get_rcx_if_valid(svm, ghcb);
3267 vcpu->arch.regs[VCPU_REGS_RDX] = kvm_ghcb_get_rdx_if_valid(svm, ghcb);
3268 vcpu->arch.regs[VCPU_REGS_RSI] = kvm_ghcb_get_rsi_if_valid(svm, ghcb);
3269
3270 svm->vmcb->save.cpl = kvm_ghcb_get_cpl_if_valid(svm, ghcb);
3271
3272 if (kvm_ghcb_xcr0_is_valid(svm)) {
3273 vcpu->arch.xcr0 = ghcb_get_xcr0(ghcb);
3274 kvm_update_cpuid_runtime(vcpu);
3275 }
3276
3277 /* Copy the GHCB exit information into the VMCB fields */
3278 exit_code = ghcb_get_sw_exit_code(ghcb);
3279 control->exit_code = lower_32_bits(exit_code);
3280 control->exit_code_hi = upper_32_bits(exit_code);
3281 control->exit_info_1 = ghcb_get_sw_exit_info_1(ghcb);
3282 control->exit_info_2 = ghcb_get_sw_exit_info_2(ghcb);
3283 svm->sev_es.sw_scratch = kvm_ghcb_get_sw_scratch_if_valid(svm, ghcb);
3284
3285 /* Clear the valid entries fields */
3286 memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
3287 }
3288
3289 static u64 kvm_ghcb_get_sw_exit_code(struct vmcb_control_area *control)
3290 {
3291 return (((u64)control->exit_code_hi) << 32) | control->exit_code;
3292 }
3293
3294 static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
3295 {
3296 struct vmcb_control_area *control = &svm->vmcb->control;
3297 struct kvm_vcpu *vcpu = &svm->vcpu;
3298 u64 exit_code;
3299 u64 reason;
3300
3301 /*
3302 * Retrieve the exit code now even though it may not be marked valid
3303 * as it could help with debugging.
3304 */
3305 exit_code = kvm_ghcb_get_sw_exit_code(control);
3306
3307 /* Only GHCB Usage code 0 is supported */
3308 if (svm->sev_es.ghcb->ghcb_usage) {
3309 reason = GHCB_ERR_INVALID_USAGE;
3310 goto vmgexit_err;
3311 }
3312
3313 reason = GHCB_ERR_MISSING_INPUT;
3314
3315 if (!kvm_ghcb_sw_exit_code_is_valid(svm) ||
3316 !kvm_ghcb_sw_exit_info_1_is_valid(svm) ||
3317 !kvm_ghcb_sw_exit_info_2_is_valid(svm))
3318 goto vmgexit_err;
3319
3320 switch (exit_code) {
3321 case SVM_EXIT_READ_DR7:
3322 break;
3323 case SVM_EXIT_WRITE_DR7:
3324 if (!kvm_ghcb_rax_is_valid(svm))
3325 goto vmgexit_err;
3326 break;
3327 case SVM_EXIT_RDTSC:
3328 break;
3329 case SVM_EXIT_RDPMC:
3330 if (!kvm_ghcb_rcx_is_valid(svm))
3331 goto vmgexit_err;
3332 break;
3333 case SVM_EXIT_CPUID:
3334 if (!kvm_ghcb_rax_is_valid(svm) ||
3335 !kvm_ghcb_rcx_is_valid(svm))
3336 goto vmgexit_err;
3337 if (vcpu->arch.regs[VCPU_REGS_RAX] == 0xd)
3338 if (!kvm_ghcb_xcr0_is_valid(svm))
3339 goto vmgexit_err;
3340 break;
3341 case SVM_EXIT_INVD:
3342 break;
3343 case SVM_EXIT_IOIO:
3344 if (control->exit_info_1 & SVM_IOIO_STR_MASK) {
3345 if (!kvm_ghcb_sw_scratch_is_valid(svm))
3346 goto vmgexit_err;
3347 } else {
3348 if (!(control->exit_info_1 & SVM_IOIO_TYPE_MASK))
3349 if (!kvm_ghcb_rax_is_valid(svm))
3350 goto vmgexit_err;
3351 }
3352 break;
3353 case SVM_EXIT_MSR:
3354 if (!kvm_ghcb_rcx_is_valid(svm))
3355 goto vmgexit_err;
3356 if (control->exit_info_1) {
3357 if (!kvm_ghcb_rax_is_valid(svm) ||
3358 !kvm_ghcb_rdx_is_valid(svm))
3359 goto vmgexit_err;
3360 }
3361 break;
3362 case SVM_EXIT_VMMCALL:
3363 if (!kvm_ghcb_rax_is_valid(svm) ||
3364 !kvm_ghcb_cpl_is_valid(svm))
3365 goto vmgexit_err;
3366 break;
3367 case SVM_EXIT_RDTSCP:
3368 break;
3369 case SVM_EXIT_WBINVD:
3370 break;
3371 case SVM_EXIT_MONITOR:
3372 if (!kvm_ghcb_rax_is_valid(svm) ||
3373 !kvm_ghcb_rcx_is_valid(svm) ||
3374 !kvm_ghcb_rdx_is_valid(svm))
3375 goto vmgexit_err;
3376 break;
3377 case SVM_EXIT_MWAIT:
3378 if (!kvm_ghcb_rax_is_valid(svm) ||
3379 !kvm_ghcb_rcx_is_valid(svm))
3380 goto vmgexit_err;
3381 break;
3382 case SVM_VMGEXIT_MMIO_READ:
3383 case SVM_VMGEXIT_MMIO_WRITE:
3384 if (!kvm_ghcb_sw_scratch_is_valid(svm))
3385 goto vmgexit_err;
3386 break;
3387 case SVM_VMGEXIT_AP_CREATION:
3388 if (!sev_snp_guest(vcpu->kvm))
3389 goto vmgexit_err;
3390 if (lower_32_bits(control->exit_info_1) != SVM_VMGEXIT_AP_DESTROY)
3391 if (!kvm_ghcb_rax_is_valid(svm))
3392 goto vmgexit_err;
3393 break;
3394 case SVM_VMGEXIT_NMI_COMPLETE:
3395 case SVM_VMGEXIT_AP_HLT_LOOP:
3396 case SVM_VMGEXIT_AP_JUMP_TABLE:
3397 case SVM_VMGEXIT_UNSUPPORTED_EVENT:
3398 case SVM_VMGEXIT_HV_FEATURES:
3399 case SVM_VMGEXIT_TERM_REQUEST:
3400 break;
3401 case SVM_VMGEXIT_PSC:
3402 if (!sev_snp_guest(vcpu->kvm) || !kvm_ghcb_sw_scratch_is_valid(svm))
3403 goto vmgexit_err;
3404 break;
3405 case SVM_VMGEXIT_GUEST_REQUEST:
3406 case SVM_VMGEXIT_EXT_GUEST_REQUEST:
3407 if (!sev_snp_guest(vcpu->kvm) ||
3408 !PAGE_ALIGNED(control->exit_info_1) ||
3409 !PAGE_ALIGNED(control->exit_info_2) ||
3410 control->exit_info_1 == control->exit_info_2)
3411 goto vmgexit_err;
3412 break;
3413 default:
3414 reason = GHCB_ERR_INVALID_EVENT;
3415 goto vmgexit_err;
3416 }
3417
3418 return 0;
3419
3420 vmgexit_err:
3421 if (reason == GHCB_ERR_INVALID_USAGE) {
3422 vcpu_unimpl(vcpu, "vmgexit: ghcb usage %#x is not valid\n",
3423 svm->sev_es.ghcb->ghcb_usage);
3424 } else if (reason == GHCB_ERR_INVALID_EVENT) {
3425 vcpu_unimpl(vcpu, "vmgexit: exit code %#llx is not valid\n",
3426 exit_code);
3427 } else {
3428 vcpu_unimpl(vcpu, "vmgexit: exit code %#llx input is not valid\n",
3429 exit_code);
3430 dump_ghcb(svm);
3431 }
3432
3433 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
3434 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, reason);
3435
3436 /* Resume the guest to "return" the error code. */
3437 return 1;
3438 }
3439
3440 void sev_es_unmap_ghcb(struct vcpu_svm *svm)
3441 {
3442 /* Clear any indication that the vCPU is in a type of AP Reset Hold */
3443 svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_NONE;
3444
3445 if (!svm->sev_es.ghcb)
3446 return;
3447
3448 if (svm->sev_es.ghcb_sa_free) {
3449 /*
3450 * The scratch area lives outside the GHCB, so there is a
3451 * buffer that, depending on the operation performed, may
3452 * need to be synced, then freed.
3453 */
3454 if (svm->sev_es.ghcb_sa_sync) {
3455 kvm_write_guest(svm->vcpu.kvm,
3456 svm->sev_es.sw_scratch,
3457 svm->sev_es.ghcb_sa,
3458 svm->sev_es.ghcb_sa_len);
3459 svm->sev_es.ghcb_sa_sync = false;
3460 }
3461
3462 kvfree(svm->sev_es.ghcb_sa);
3463 svm->sev_es.ghcb_sa = NULL;
3464 svm->sev_es.ghcb_sa_free = false;
3465 }
3466
3467 trace_kvm_vmgexit_exit(svm->vcpu.vcpu_id, svm->sev_es.ghcb);
3468
3469 sev_es_sync_to_ghcb(svm);
3470
3471 kvm_vcpu_unmap(&svm->vcpu, &svm->sev_es.ghcb_map, true);
3472 svm->sev_es.ghcb = NULL;
3473 }
3474
3475 void pre_sev_run(struct vcpu_svm *svm, int cpu)
3476 {
3477 struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
3478 unsigned int asid = sev_get_asid(svm->vcpu.kvm);
3479
3480 /* Assign the asid allocated with this SEV guest */
3481 svm->asid = asid;
3482
3483 /*
3484 * Flush guest TLB:
3485 *
3486 * 1) when different VMCB for the same ASID is to be run on the same host CPU.
3487 * 2) or this VMCB was executed on different host CPU in previous VMRUNs.
3488 */
3489 if (sd->sev_vmcbs[asid] == svm->vmcb &&
3490 svm->vcpu.arch.last_vmentry_cpu == cpu)
3491 return;
3492
3493 sd->sev_vmcbs[asid] = svm->vmcb;
3494 svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
3495 vmcb_mark_dirty(svm->vmcb, VMCB_ASID);
3496 }
3497
3498 #define GHCB_SCRATCH_AREA_LIMIT (16ULL * PAGE_SIZE)
3499 static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
3500 {
3501 struct vmcb_control_area *control = &svm->vmcb->control;
3502 u64 ghcb_scratch_beg, ghcb_scratch_end;
3503 u64 scratch_gpa_beg, scratch_gpa_end;
3504 void *scratch_va;
3505
3506 scratch_gpa_beg = svm->sev_es.sw_scratch;
3507 if (!scratch_gpa_beg) {
3508 pr_err("vmgexit: scratch gpa not provided\n");
3509 goto e_scratch;
3510 }
3511
3512 scratch_gpa_end = scratch_gpa_beg + len;
3513 if (scratch_gpa_end < scratch_gpa_beg) {
3514 pr_err("vmgexit: scratch length (%#llx) not valid for scratch address (%#llx)\n",
3515 len, scratch_gpa_beg);
3516 goto e_scratch;
3517 }
3518
3519 if ((scratch_gpa_beg & PAGE_MASK) == control->ghcb_gpa) {
3520 /* Scratch area begins within GHCB */
3521 ghcb_scratch_beg = control->ghcb_gpa +
3522 offsetof(struct ghcb, shared_buffer);
3523 ghcb_scratch_end = control->ghcb_gpa +
3524 offsetof(struct ghcb, reserved_0xff0);
3525
3526 /*
3527 * If the scratch area begins within the GHCB, it must be
3528 * completely contained in the GHCB shared buffer area.
3529 */
3530 if (scratch_gpa_beg < ghcb_scratch_beg ||
3531 scratch_gpa_end > ghcb_scratch_end) {
3532 pr_err("vmgexit: scratch area is outside of GHCB shared buffer area (%#llx - %#llx)\n",
3533 scratch_gpa_beg, scratch_gpa_end);
3534 goto e_scratch;
3535 }
3536
3537 scratch_va = (void *)svm->sev_es.ghcb;
3538 scratch_va += (scratch_gpa_beg - control->ghcb_gpa);
3539 } else {
3540 /*
3541 * The guest memory must be read into a kernel buffer, so
3542 * limit the size
3543 */
3544 if (len > GHCB_SCRATCH_AREA_LIMIT) {
3545 pr_err("vmgexit: scratch area exceeds KVM limits (%#llx requested, %#llx limit)\n",
3546 len, GHCB_SCRATCH_AREA_LIMIT);
3547 goto e_scratch;
3548 }
3549 scratch_va = kvzalloc(len, GFP_KERNEL_ACCOUNT);
3550 if (!scratch_va)
3551 return -ENOMEM;
3552
3553 if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) {
3554 /* Unable to copy scratch area from guest */
3555 pr_err("vmgexit: kvm_read_guest for scratch area failed\n");
3556
3557 kvfree(scratch_va);
3558 return -EFAULT;
3559 }
3560
3561 /*
3562 * The scratch area is outside the GHCB. The operation will
3563 * dictate whether the buffer needs to be synced before running
3564 * the vCPU next time (i.e. a read was requested so the data
3565 * must be written back to the guest memory).
3566 */
3567 svm->sev_es.ghcb_sa_sync = sync;
3568 svm->sev_es.ghcb_sa_free = true;
3569 }
3570
3571 svm->sev_es.ghcb_sa = scratch_va;
3572 svm->sev_es.ghcb_sa_len = len;
3573
3574 return 0;
3575
3576 e_scratch:
3577 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
3578 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_SCRATCH_AREA);
3579
3580 return 1;
3581 }
3582
3583 static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask,
3584 unsigned int pos)
3585 {
3586 svm->vmcb->control.ghcb_gpa &= ~(mask << pos);
3587 svm->vmcb->control.ghcb_gpa |= (value & mask) << pos;
3588 }
3589
3590 static u64 get_ghcb_msr_bits(struct vcpu_svm *svm, u64 mask, unsigned int pos)
3591 {
3592 return (svm->vmcb->control.ghcb_gpa >> pos) & mask;
3593 }
3594
3595 static void set_ghcb_msr(struct vcpu_svm *svm, u64 value)
3596 {
3597 svm->vmcb->control.ghcb_gpa = value;
3598 }
3599
3600 static int snp_rmptable_psmash(kvm_pfn_t pfn)
3601 {
3602 int ret;
3603
3604 pfn = pfn & ~(KVM_PAGES_PER_HPAGE(PG_LEVEL_2M) - 1);
3605
3606 /*
3607 * PSMASH_FAIL_INUSE indicates another processor is modifying the
3608 * entry, so retry until that's no longer the case.
3609 */
3610 do {
3611 ret = psmash(pfn);
3612 } while (ret == PSMASH_FAIL_INUSE);
3613
3614 return ret;
3615 }
3616
3617 static int snp_complete_psc_msr(struct kvm_vcpu *vcpu)
3618 {
3619 struct vcpu_svm *svm = to_svm(vcpu);
3620
3621 if (vcpu->run->hypercall.ret)
3622 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
3623 else
3624 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP);
3625
3626 return 1; /* resume guest */
3627 }
3628
3629 static int snp_begin_psc_msr(struct vcpu_svm *svm, u64 ghcb_msr)
3630 {
3631 u64 gpa = gfn_to_gpa(GHCB_MSR_PSC_REQ_TO_GFN(ghcb_msr));
3632 u8 op = GHCB_MSR_PSC_REQ_TO_OP(ghcb_msr);
3633 struct kvm_vcpu *vcpu = &svm->vcpu;
3634
3635 if (op != SNP_PAGE_STATE_PRIVATE && op != SNP_PAGE_STATE_SHARED) {
3636 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
3637 return 1; /* resume guest */
3638 }
3639
3640 if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) {
3641 set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
3642 return 1; /* resume guest */
3643 }
3644
3645 vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
3646 vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE;
3647 vcpu->run->hypercall.args[0] = gpa;
3648 vcpu->run->hypercall.args[1] = 1;
3649 vcpu->run->hypercall.args[2] = (op == SNP_PAGE_STATE_PRIVATE)
3650 ? KVM_MAP_GPA_RANGE_ENCRYPTED
3651 : KVM_MAP_GPA_RANGE_DECRYPTED;
3652 vcpu->run->hypercall.args[2] |= KVM_MAP_GPA_RANGE_PAGE_SZ_4K;
3653
3654 vcpu->arch.complete_userspace_io = snp_complete_psc_msr;
3655
3656 return 0; /* forward request to userspace */
3657 }
3658
3659 struct psc_buffer {
3660 struct psc_hdr hdr;
3661 struct psc_entry entries[];
3662 } __packed;
3663
3664 static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc);
3665
3666 static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret)
3667 {
3668 svm->sev_es.psc_inflight = 0;
3669 svm->sev_es.psc_idx = 0;
3670 svm->sev_es.psc_2m = false;
3671 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, psc_ret);
3672 }
3673
3674 static void __snp_complete_one_psc(struct vcpu_svm *svm)
3675 {
3676 struct psc_buffer *psc = svm->sev_es.ghcb_sa;
3677 struct psc_entry *entries = psc->entries;
3678 struct psc_hdr *hdr = &psc->hdr;
3679 __u16 idx;
3680
3681 /*
3682 * Everything in-flight has been processed successfully. Update the
3683 * corresponding entries in the guest's PSC buffer and zero out the
3684 * count of in-flight PSC entries.
3685 */
3686 for (idx = svm->sev_es.psc_idx; svm->sev_es.psc_inflight;
3687 svm->sev_es.psc_inflight--, idx++) {
3688 struct psc_entry *entry = &entries[idx];
3689
3690 entry->cur_page = entry->pagesize ? 512 : 1;
3691 }
3692
3693 hdr->cur_entry = idx;
3694 }
3695
3696 static int snp_complete_one_psc(struct kvm_vcpu *vcpu)
3697 {
3698 struct vcpu_svm *svm = to_svm(vcpu);
3699 struct psc_buffer *psc = svm->sev_es.ghcb_sa;
3700
3701 if (vcpu->run->hypercall.ret) {
3702 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
3703 return 1; /* resume guest */
3704 }
3705
3706 __snp_complete_one_psc(svm);
3707
3708 /* Handle the next range (if any). */
3709 return snp_begin_psc(svm, psc);
3710 }
3711
3712 static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc)
3713 {
3714 struct psc_entry *entries = psc->entries;
3715 struct kvm_vcpu *vcpu = &svm->vcpu;
3716 struct psc_hdr *hdr = &psc->hdr;
3717 struct psc_entry entry_start;
3718 u16 idx, idx_start, idx_end;
3719 int npages;
3720 bool huge;
3721 u64 gfn;
3722
3723 if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) {
3724 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
3725 return 1;
3726 }
3727
3728 next_range:
3729 /* There should be no other PSCs in-flight at this point. */
3730 if (WARN_ON_ONCE(svm->sev_es.psc_inflight)) {
3731 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
3732 return 1;
3733 }
3734
3735 /*
3736 * The PSC descriptor buffer can be modified by a misbehaved guest after
3737 * validation, so take care to only use validated copies of values used
3738 * for things like array indexing.
3739 */
3740 idx_start = hdr->cur_entry;
3741 idx_end = hdr->end_entry;
3742
3743 if (idx_end >= VMGEXIT_PSC_MAX_COUNT) {
3744 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_INVALID_HDR);
3745 return 1;
3746 }
3747
3748 /* Find the start of the next range which needs processing. */
3749 for (idx = idx_start; idx <= idx_end; idx++, hdr->cur_entry++) {
3750 entry_start = entries[idx];
3751
3752 gfn = entry_start.gfn;
3753 huge = entry_start.pagesize;
3754 npages = huge ? 512 : 1;
3755
3756 if (entry_start.cur_page > npages || !IS_ALIGNED(gfn, npages)) {
3757 snp_complete_psc(svm, VMGEXIT_PSC_ERROR_INVALID_ENTRY);
3758 return 1;
3759 }
3760
3761 if (entry_start.cur_page) {
3762 /*
3763 * If this is a partially-completed 2M range, force 4K handling
3764 * for the remaining pages since they're effectively split at
3765 * this point. Subsequent code should ensure this doesn't get
3766 * combined with adjacent PSC entries where 2M handling is still
3767 * possible.
3768 */
3769 npages -= entry_start.cur_page;
3770 gfn += entry_start.cur_page;
3771 huge = false;
3772 }
3773
3774 if (npages)
3775 break;
3776 }
3777
3778 if (idx > idx_end) {
3779 /* Nothing more to process. */
3780 snp_complete_psc(svm, 0);
3781 return 1;
3782 }
3783
3784 svm->sev_es.psc_2m = huge;
3785 svm->sev_es.psc_idx = idx;
3786 svm->sev_es.psc_inflight = 1;
3787
3788 /*
3789 * Find all subsequent PSC entries that contain adjacent GPA
3790 * ranges/operations and can be combined into a single
3791 * KVM_HC_MAP_GPA_RANGE exit.
3792 */
3793 while (++idx <= idx_end) {
3794 struct psc_entry entry = entries[idx];
3795
3796 if (entry.operation != entry_start.operation ||
3797 entry.gfn != entry_start.gfn + npages ||
3798 entry.cur_page || !!entry.pagesize != huge)
3799 break;
3800
3801 svm->sev_es.psc_inflight++;
3802 npages += huge ? 512 : 1;
3803 }
3804
3805 switch (entry_start.operation) {
3806 case VMGEXIT_PSC_OP_PRIVATE:
3807 case VMGEXIT_PSC_OP_SHARED:
3808 vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
3809 vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE;
3810 vcpu->run->hypercall.args[0] = gfn_to_gpa(gfn);
3811 vcpu->run->hypercall.args[1] = npages;
3812 vcpu->run->hypercall.args[2] = entry_start.operation == VMGEXIT_PSC_OP_PRIVATE
3813 ? KVM_MAP_GPA_RANGE_ENCRYPTED
3814 : KVM_MAP_GPA_RANGE_DECRYPTED;
3815 vcpu->run->hypercall.args[2] |= entry_start.pagesize
3816 ? KVM_MAP_GPA_RANGE_PAGE_SZ_2M
3817 : KVM_MAP_GPA_RANGE_PAGE_SZ_4K;
3818 vcpu->arch.complete_userspace_io = snp_complete_one_psc;
3819 return 0; /* forward request to userspace */
3820 default:
3821 /*
3822 * Only shared/private PSC operations are currently supported, so if the
3823 * entire range consists of unsupported operations (e.g. SMASH/UNSMASH),
3824 * then consider the entire range completed and avoid exiting to
3825 * userspace. In theory snp_complete_psc() can always be called directly
3826 * at this point to complete the current range and start the next one,
3827 * but that could lead to unexpected levels of recursion.
3828 */
3829 __snp_complete_one_psc(svm);
3830 goto next_range;
3831 }
3832
3833 unreachable();
3834 }
3835
3836 static int __sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu)
3837 {
3838 struct vcpu_svm *svm = to_svm(vcpu);
3839
3840 WARN_ON(!mutex_is_locked(&svm->sev_es.snp_vmsa_mutex));
3841
3842 /* Mark the vCPU as offline and not runnable */
3843 vcpu->arch.pv.pv_unhalted = false;
3844 vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
3845
3846 /* Clear use of the VMSA */
3847 svm->vmcb->control.vmsa_pa = INVALID_PAGE;
3848
3849 if (VALID_PAGE(svm->sev_es.snp_vmsa_gpa)) {
3850 gfn_t gfn = gpa_to_gfn(svm->sev_es.snp_vmsa_gpa);
3851 struct kvm_memory_slot *slot;
3852 kvm_pfn_t pfn;
3853
3854 slot = gfn_to_memslot(vcpu->kvm, gfn);
3855 if (!slot)
3856 return -EINVAL;
3857
3858 /*
3859 * The new VMSA will be private memory guest memory, so
3860 * retrieve the PFN from the gmem backend.
3861 */
3862 if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, NULL))
3863 return -EINVAL;
3864
3865 /*
3866 * From this point forward, the VMSA will always be a
3867 * guest-mapped page rather than the initial one allocated
3868 * by KVM in svm->sev_es.vmsa. In theory, svm->sev_es.vmsa
3869 * could be free'd and cleaned up here, but that involves
3870 * cleanups like wbinvd_on_all_cpus() which would ideally
3871 * be handled during teardown rather than guest boot.
3872 * Deferring that also allows the existing logic for SEV-ES
3873 * VMSAs to be re-used with minimal SNP-specific changes.
3874 */
3875 svm->sev_es.snp_has_guest_vmsa = true;
3876
3877 /* Use the new VMSA */
3878 svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn);
3879
3880 /* Mark the vCPU as runnable */
3881 vcpu->arch.pv.pv_unhalted = false;
3882 vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
3883
3884 svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
3885
3886 /*
3887 * gmem pages aren't currently migratable, but if this ever
3888 * changes then care should be taken to ensure
3889 * svm->sev_es.vmsa is pinned through some other means.
3890 */
3891 kvm_release_pfn_clean(pfn);
3892 }
3893
3894 /*
3895 * When replacing the VMSA during SEV-SNP AP creation,
3896 * mark the VMCB dirty so that full state is always reloaded.
3897 */
3898 vmcb_mark_all_dirty(svm->vmcb);
3899
3900 return 0;
3901 }
3902
3903 /*
3904 * Invoked as part of svm_vcpu_reset() processing of an init event.
3905 */
3906 void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
3907 {
3908 struct vcpu_svm *svm = to_svm(vcpu);
3909 int ret;
3910
3911 if (!sev_snp_guest(vcpu->kvm))
3912 return;
3913
3914 mutex_lock(&svm->sev_es.snp_vmsa_mutex);
3915
3916 if (!svm->sev_es.snp_ap_waiting_for_reset)
3917 goto unlock;
3918
3919 svm->sev_es.snp_ap_waiting_for_reset = false;
3920
3921 ret = __sev_snp_update_protected_guest_state(vcpu);
3922 if (ret)
3923 vcpu_unimpl(vcpu, "snp: AP state update on init failed\n");
3924
3925 unlock:
3926 mutex_unlock(&svm->sev_es.snp_vmsa_mutex);
3927 }
3928
3929 static int sev_snp_ap_creation(struct vcpu_svm *svm)
3930 {
3931 struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info;
3932 struct kvm_vcpu *vcpu = &svm->vcpu;
3933 struct kvm_vcpu *target_vcpu;
3934 struct vcpu_svm *target_svm;
3935 unsigned int request;
3936 unsigned int apic_id;
3937 bool kick;
3938 int ret;
3939
3940 request = lower_32_bits(svm->vmcb->control.exit_info_1);
3941 apic_id = upper_32_bits(svm->vmcb->control.exit_info_1);
3942
3943 /* Validate the APIC ID */
3944 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, apic_id);
3945 if (!target_vcpu) {
3946 vcpu_unimpl(vcpu, "vmgexit: invalid AP APIC ID [%#x] from guest\n",
3947 apic_id);
3948 return -EINVAL;
3949 }
3950
3951 ret = 0;
3952
3953 target_svm = to_svm(target_vcpu);
3954
3955 /*
3956 * The target vCPU is valid, so the vCPU will be kicked unless the
3957 * request is for CREATE_ON_INIT. For any errors at this stage, the
3958 * kick will place the vCPU in an non-runnable state.
3959 */
3960 kick = true;
3961
3962 mutex_lock(&target_svm->sev_es.snp_vmsa_mutex);
3963
3964 target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE;
3965 target_svm->sev_es.snp_ap_waiting_for_reset = true;
3966
3967 /* Interrupt injection mode shouldn't change for AP creation */
3968 if (request < SVM_VMGEXIT_AP_DESTROY) {
3969 u64 sev_features;
3970
3971 sev_features = vcpu->arch.regs[VCPU_REGS_RAX];
3972 sev_features ^= sev->vmsa_features;
3973
3974 if (sev_features & SVM_SEV_FEAT_INT_INJ_MODES) {
3975 vcpu_unimpl(vcpu, "vmgexit: invalid AP injection mode [%#lx] from guest\n",
3976 vcpu->arch.regs[VCPU_REGS_RAX]);
3977 ret = -EINVAL;
3978 goto out;
3979 }
3980 }
3981
3982 switch (request) {
3983 case SVM_VMGEXIT_AP_CREATE_ON_INIT:
3984 kick = false;
3985 fallthrough;
3986 case SVM_VMGEXIT_AP_CREATE:
3987 if (!page_address_valid(vcpu, svm->vmcb->control.exit_info_2)) {
3988 vcpu_unimpl(vcpu, "vmgexit: invalid AP VMSA address [%#llx] from guest\n",
3989 svm->vmcb->control.exit_info_2);
3990 ret = -EINVAL;
3991 goto out;
3992 }
3993
3994 /*
3995 * Malicious guest can RMPADJUST a large page into VMSA which
3996 * will hit the SNP erratum where the CPU will incorrectly signal
3997 * an RMP violation #PF if a hugepage collides with the RMP entry
3998 * of VMSA page, reject the AP CREATE request if VMSA address from
3999 * guest is 2M aligned.
4000 */
4001 if (IS_ALIGNED(svm->vmcb->control.exit_info_2, PMD_SIZE)) {
4002 vcpu_unimpl(vcpu,
4003 "vmgexit: AP VMSA address [%llx] from guest is unsafe as it is 2M aligned\n",
4004 svm->vmcb->control.exit_info_2);
4005 ret = -EINVAL;
4006 goto out;
4007 }
4008
4009 target_svm->sev_es.snp_vmsa_gpa = svm->vmcb->control.exit_info_2;
4010 break;
4011 case SVM_VMGEXIT_AP_DESTROY:
4012 break;
4013 default:
4014 vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n",
4015 request);
4016 ret = -EINVAL;
4017 break;
4018 }
4019
4020 out:
4021 if (kick) {
4022 kvm_make_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu);
4023 kvm_vcpu_kick(target_vcpu);
4024 }
4025
4026 mutex_unlock(&target_svm->sev_es.snp_vmsa_mutex);
4027
4028 return ret;
4029 }
4030
4031 static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa)
4032 {
4033 struct sev_data_snp_guest_request data = {0};
4034 struct kvm *kvm = svm->vcpu.kvm;
4035 struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
4036 sev_ret_code fw_err = 0;
4037 int ret;
4038
4039 if (!sev_snp_guest(kvm))
4040 return -EINVAL;
4041
4042 mutex_lock(&sev->guest_req_mutex);
4043
4044 if (kvm_read_guest(kvm, req_gpa, sev->guest_req_buf, PAGE_SIZE)) {
4045 ret = -EIO;
4046 goto out_unlock;
4047 }
4048
4049 data.gctx_paddr = __psp_pa(sev->snp_context);
4050 data.req_paddr = __psp_pa(sev->guest_req_buf);
4051 data.res_paddr = __psp_pa(sev->guest_resp_buf);
4052
4053 /*
4054 * Firmware failures are propagated on to guest, but any other failure
4055 * condition along the way should be reported to userspace. E.g. if
4056 * the PSP is dead and commands are timing out.
4057 */
4058 ret = sev_issue_cmd(kvm, SEV_CMD_SNP_GUEST_REQUEST, &data, &fw_err);
4059 if (ret && !fw_err)
4060 goto out_unlock;
4061
4062 if (kvm_write_guest(kvm, resp_gpa, sev->guest_resp_buf, PAGE_SIZE)) {
4063 ret = -EIO;
4064 goto out_unlock;
4065 }
4066
4067 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, SNP_GUEST_ERR(0, fw_err));
4068
4069 ret = 1; /* resume guest */
4070
4071 out_unlock:
4072 mutex_unlock(&sev->guest_req_mutex);
4073 return ret;
4074 }
4075
4076 static int snp_handle_ext_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa)
4077 {
4078 struct kvm *kvm = svm->vcpu.kvm;
4079 u8 msg_type;
4080
4081 if (!sev_snp_guest(kvm))
4082 return -EINVAL;
4083
4084 if (kvm_read_guest(kvm, req_gpa + offsetof(struct snp_guest_msg_hdr, msg_type),
4085 &msg_type, 1))
4086 return -EIO;
4087
4088 /*
4089 * As per GHCB spec, requests of type MSG_REPORT_REQ also allow for
4090 * additional certificate data to be provided alongside the attestation
4091 * report via the guest-provided data pages indicated by RAX/RBX. The
4092 * certificate data is optional and requires additional KVM enablement
4093 * to provide an interface for userspace to provide it, but KVM still
4094 * needs to be able to handle extended guest requests either way. So
4095 * provide a stub implementation that will always return an empty
4096 * certificate table in the guest-provided data pages.
4097 */
4098 if (msg_type == SNP_MSG_REPORT_REQ) {
4099 struct kvm_vcpu *vcpu = &svm->vcpu;
4100 u64 data_npages;
4101 gpa_t data_gpa;
4102
4103 if (!kvm_ghcb_rax_is_valid(svm) || !kvm_ghcb_rbx_is_valid(svm))
4104 goto request_invalid;
4105
4106 data_gpa = vcpu->arch.regs[VCPU_REGS_RAX];
4107 data_npages = vcpu->arch.regs[VCPU_REGS_RBX];
4108
4109 if (!PAGE_ALIGNED(data_gpa))
4110 goto request_invalid;
4111
4112 /*
4113 * As per GHCB spec (see "SNP Extended Guest Request"), the
4114 * certificate table is terminated by 24-bytes of zeroes.
4115 */
4116 if (data_npages && kvm_clear_guest(kvm, data_gpa, 24))
4117 return -EIO;
4118 }
4119
4120 return snp_handle_guest_req(svm, req_gpa, resp_gpa);
4121
4122 request_invalid:
4123 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
4124 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
4125 return 1; /* resume guest */
4126 }
4127
4128 static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
4129 {
4130 struct vmcb_control_area *control = &svm->vmcb->control;
4131 struct kvm_vcpu *vcpu = &svm->vcpu;
4132 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
4133 u64 ghcb_info;
4134 int ret = 1;
4135
4136 ghcb_info = control->ghcb_gpa & GHCB_MSR_INFO_MASK;
4137
4138 trace_kvm_vmgexit_msr_protocol_enter(svm->vcpu.vcpu_id,
4139 control->ghcb_gpa);
4140
4141 switch (ghcb_info) {
4142 case GHCB_MSR_SEV_INFO_REQ:
4143 set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
4144 GHCB_VERSION_MIN,
4145 sev_enc_bit));
4146 break;
4147 case GHCB_MSR_CPUID_REQ: {
4148 u64 cpuid_fn, cpuid_reg, cpuid_value;
4149
4150 cpuid_fn = get_ghcb_msr_bits(svm,
4151 GHCB_MSR_CPUID_FUNC_MASK,
4152 GHCB_MSR_CPUID_FUNC_POS);
4153
4154 /* Initialize the registers needed by the CPUID intercept */
4155 vcpu->arch.regs[VCPU_REGS_RAX] = cpuid_fn;
4156 vcpu->arch.regs[VCPU_REGS_RCX] = 0;
4157
4158 ret = svm_invoke_exit_handler(vcpu, SVM_EXIT_CPUID);
4159 if (!ret) {
4160 /* Error, keep GHCB MSR value as-is */
4161 break;
4162 }
4163
4164 cpuid_reg = get_ghcb_msr_bits(svm,
4165 GHCB_MSR_CPUID_REG_MASK,
4166 GHCB_MSR_CPUID_REG_POS);
4167 if (cpuid_reg == 0)
4168 cpuid_value = vcpu->arch.regs[VCPU_REGS_RAX];
4169 else if (cpuid_reg == 1)
4170 cpuid_value = vcpu->arch.regs[VCPU_REGS_RBX];
4171 else if (cpuid_reg == 2)
4172 cpuid_value = vcpu->arch.regs[VCPU_REGS_RCX];
4173 else
4174 cpuid_value = vcpu->arch.regs[VCPU_REGS_RDX];
4175
4176 set_ghcb_msr_bits(svm, cpuid_value,
4177 GHCB_MSR_CPUID_VALUE_MASK,
4178 GHCB_MSR_CPUID_VALUE_POS);
4179
4180 set_ghcb_msr_bits(svm, GHCB_MSR_CPUID_RESP,
4181 GHCB_MSR_INFO_MASK,
4182 GHCB_MSR_INFO_POS);
4183 break;
4184 }
4185 case GHCB_MSR_AP_RESET_HOLD_REQ:
4186 svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_MSR_PROTO;
4187 ret = kvm_emulate_ap_reset_hold(&svm->vcpu);
4188
4189 /*
4190 * Preset the result to a non-SIPI return and then only set
4191 * the result to non-zero when delivering a SIPI.
4192 */
4193 set_ghcb_msr_bits(svm, 0,
4194 GHCB_MSR_AP_RESET_HOLD_RESULT_MASK,
4195 GHCB_MSR_AP_RESET_HOLD_RESULT_POS);
4196
4197 set_ghcb_msr_bits(svm, GHCB_MSR_AP_RESET_HOLD_RESP,
4198 GHCB_MSR_INFO_MASK,
4199 GHCB_MSR_INFO_POS);
4200 break;
4201 case GHCB_MSR_HV_FT_REQ:
4202 set_ghcb_msr_bits(svm, GHCB_HV_FT_SUPPORTED,
4203 GHCB_MSR_HV_FT_MASK, GHCB_MSR_HV_FT_POS);
4204 set_ghcb_msr_bits(svm, GHCB_MSR_HV_FT_RESP,
4205 GHCB_MSR_INFO_MASK, GHCB_MSR_INFO_POS);
4206 break;
4207 case GHCB_MSR_PREF_GPA_REQ:
4208 if (!sev_snp_guest(vcpu->kvm))
4209 goto out_terminate;
4210
4211 set_ghcb_msr_bits(svm, GHCB_MSR_PREF_GPA_NONE, GHCB_MSR_GPA_VALUE_MASK,
4212 GHCB_MSR_GPA_VALUE_POS);
4213 set_ghcb_msr_bits(svm, GHCB_MSR_PREF_GPA_RESP, GHCB_MSR_INFO_MASK,
4214 GHCB_MSR_INFO_POS);
4215 break;
4216 case GHCB_MSR_REG_GPA_REQ: {
4217 u64 gfn;
4218
4219 if (!sev_snp_guest(vcpu->kvm))
4220 goto out_terminate;
4221
4222 gfn = get_ghcb_msr_bits(svm, GHCB_MSR_GPA_VALUE_MASK,
4223 GHCB_MSR_GPA_VALUE_POS);
4224
4225 svm->sev_es.ghcb_registered_gpa = gfn_to_gpa(gfn);
4226
4227 set_ghcb_msr_bits(svm, gfn, GHCB_MSR_GPA_VALUE_MASK,
4228 GHCB_MSR_GPA_VALUE_POS);
4229 set_ghcb_msr_bits(svm, GHCB_MSR_REG_GPA_RESP, GHCB_MSR_INFO_MASK,
4230 GHCB_MSR_INFO_POS);
4231 break;
4232 }
4233 case GHCB_MSR_PSC_REQ:
4234 if (!sev_snp_guest(vcpu->kvm))
4235 goto out_terminate;
4236
4237 ret = snp_begin_psc_msr(svm, control->ghcb_gpa);
4238 break;
4239 case GHCB_MSR_TERM_REQ: {
4240 u64 reason_set, reason_code;
4241
4242 reason_set = get_ghcb_msr_bits(svm,
4243 GHCB_MSR_TERM_REASON_SET_MASK,
4244 GHCB_MSR_TERM_REASON_SET_POS);
4245 reason_code = get_ghcb_msr_bits(svm,
4246 GHCB_MSR_TERM_REASON_MASK,
4247 GHCB_MSR_TERM_REASON_POS);
4248 pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",
4249 reason_set, reason_code);
4250
4251 goto out_terminate;
4252 }
4253 default:
4254 /* Error, keep GHCB MSR value as-is */
4255 break;
4256 }
4257
4258 trace_kvm_vmgexit_msr_protocol_exit(svm->vcpu.vcpu_id,
4259 control->ghcb_gpa, ret);
4260
4261 return ret;
4262
4263 out_terminate:
4264 vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
4265 vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
4266 vcpu->run->system_event.ndata = 1;
4267 vcpu->run->system_event.data[0] = control->ghcb_gpa;
4268
4269 return 0;
4270 }
4271
4272 int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
4273 {
4274 struct vcpu_svm *svm = to_svm(vcpu);
4275 struct vmcb_control_area *control = &svm->vmcb->control;
4276 u64 ghcb_gpa, exit_code;
4277 int ret;
4278
4279 /* Validate the GHCB */
4280 ghcb_gpa = control->ghcb_gpa;
4281 if (ghcb_gpa & GHCB_MSR_INFO_MASK)
4282 return sev_handle_vmgexit_msr_protocol(svm);
4283
4284 if (!ghcb_gpa) {
4285 vcpu_unimpl(vcpu, "vmgexit: GHCB gpa is not set\n");
4286
4287 /* Without a GHCB, just return right back to the guest */
4288 return 1;
4289 }
4290
4291 if (kvm_vcpu_map(vcpu, ghcb_gpa >> PAGE_SHIFT, &svm->sev_es.ghcb_map)) {
4292 /* Unable to map GHCB from guest */
4293 vcpu_unimpl(vcpu, "vmgexit: error mapping GHCB [%#llx] from guest\n",
4294 ghcb_gpa);
4295
4296 /* Without a GHCB, just return right back to the guest */
4297 return 1;
4298 }
4299
4300 svm->sev_es.ghcb = svm->sev_es.ghcb_map.hva;
4301
4302 trace_kvm_vmgexit_enter(vcpu->vcpu_id, svm->sev_es.ghcb);
4303
4304 sev_es_sync_from_ghcb(svm);
4305
4306 /* SEV-SNP guest requires that the GHCB GPA must be registered */
4307 if (sev_snp_guest(svm->vcpu.kvm) && !ghcb_gpa_is_registered(svm, ghcb_gpa)) {
4308 vcpu_unimpl(&svm->vcpu, "vmgexit: GHCB GPA [%#llx] is not registered.\n", ghcb_gpa);
4309 return -EINVAL;
4310 }
4311
4312 ret = sev_es_validate_vmgexit(svm);
4313 if (ret)
4314 return ret;
4315
4316 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 0);
4317 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 0);
4318
4319 exit_code = kvm_ghcb_get_sw_exit_code(control);
4320 switch (exit_code) {
4321 case SVM_VMGEXIT_MMIO_READ:
4322 ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);
4323 if (ret)
4324 break;
4325
4326 ret = kvm_sev_es_mmio_read(vcpu,
4327 control->exit_info_1,
4328 control->exit_info_2,
4329 svm->sev_es.ghcb_sa);
4330 break;
4331 case SVM_VMGEXIT_MMIO_WRITE:
4332 ret = setup_vmgexit_scratch(svm, false, control->exit_info_2);
4333 if (ret)
4334 break;
4335
4336 ret = kvm_sev_es_mmio_write(vcpu,
4337 control->exit_info_1,
4338 control->exit_info_2,
4339 svm->sev_es.ghcb_sa);
4340 break;
4341 case SVM_VMGEXIT_NMI_COMPLETE:
4342 ++vcpu->stat.nmi_window_exits;
4343 svm->nmi_masked = false;
4344 kvm_make_request(KVM_REQ_EVENT, vcpu);
4345 ret = 1;
4346 break;
4347 case SVM_VMGEXIT_AP_HLT_LOOP:
4348 svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_NAE_EVENT;
4349 ret = kvm_emulate_ap_reset_hold(vcpu);
4350 break;
4351 case SVM_VMGEXIT_AP_JUMP_TABLE: {
4352 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
4353
4354 switch (control->exit_info_1) {
4355 case 0:
4356 /* Set AP jump table address */
4357 sev->ap_jump_table = control->exit_info_2;
4358 break;
4359 case 1:
4360 /* Get AP jump table address */
4361 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, sev->ap_jump_table);
4362 break;
4363 default:
4364 pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",
4365 control->exit_info_1);
4366 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
4367 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
4368 }
4369
4370 ret = 1;
4371 break;
4372 }
4373 case SVM_VMGEXIT_HV_FEATURES:
4374 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_HV_FT_SUPPORTED);
4375
4376 ret = 1;
4377 break;
4378 case SVM_VMGEXIT_TERM_REQUEST:
4379 pr_info("SEV-ES guest requested termination: reason %#llx info %#llx\n",
4380 control->exit_info_1, control->exit_info_2);
4381 vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
4382 vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
4383 vcpu->run->system_event.ndata = 1;
4384 vcpu->run->system_event.data[0] = control->ghcb_gpa;
4385 break;
4386 case SVM_VMGEXIT_PSC:
4387 ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);
4388 if (ret)
4389 break;
4390
4391 ret = snp_begin_psc(svm, svm->sev_es.ghcb_sa);
4392 break;
4393 case SVM_VMGEXIT_AP_CREATION:
4394 ret = sev_snp_ap_creation(svm);
4395 if (ret) {
4396 ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2);
4397 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);
4398 }
4399
4400 ret = 1;
4401 break;
4402 case SVM_VMGEXIT_GUEST_REQUEST:
4403 ret = snp_handle_guest_req(svm, control->exit_info_1, control->exit_info_2);
4404 break;
4405 case SVM_VMGEXIT_EXT_GUEST_REQUEST:
4406 ret = snp_handle_ext_guest_req(svm, control->exit_info_1, control->exit_info_2);
4407 break;
4408 case SVM_VMGEXIT_UNSUPPORTED_EVENT:
4409 vcpu_unimpl(vcpu,
4410 "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
4411 control->exit_info_1, control->exit_info_2);
4412 ret = -EINVAL;
4413 break;
4414 default:
4415 ret = svm_invoke_exit_handler(vcpu, exit_code);
4416 }
4417
4418 return ret;
4419 }
4420
4421 int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
4422 {
4423 int count;
4424 int bytes;
4425 int r;
4426
4427 if (svm->vmcb->control.exit_info_2 > INT_MAX)
4428 return -EINVAL;
4429
4430 count = svm->vmcb->control.exit_info_2;
4431 if (unlikely(check_mul_overflow(count, size, &bytes)))
4432 return -EINVAL;
4433
4434 r = setup_vmgexit_scratch(svm, in, bytes);
4435 if (r)
4436 return r;
4437
4438 return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->sev_es.ghcb_sa,
4439 count, in);
4440 }
4441
4442 static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
4443 {
4444 struct kvm_vcpu *vcpu = &svm->vcpu;
4445
4446 if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) {
4447 bool v_tsc_aux = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) ||
4448 guest_cpuid_has(vcpu, X86_FEATURE_RDPID);
4449
4450 set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
4451 }
4452
4453 /*
4454 * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
4455 * the host/guest supports its use.
4456 *
4457 * guest_can_use() checks a number of requirements on the host/guest to
4458 * ensure that MSR_IA32_XSS is available, but it might report true even
4459 * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host
4460 * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better
4461 * to further check that the guest CPUID actually supports
4462 * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved
4463 * guests will still get intercepted and caught in the normal
4464 * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths.
4465 */
4466 if (guest_can_use(vcpu, X86_FEATURE_XSAVES) &&
4467 guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
4468 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1);
4469 else
4470 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0);
4471 }
4472
4473 void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)
4474 {
4475 struct kvm_vcpu *vcpu = &svm->vcpu;
4476 struct kvm_cpuid_entry2 *best;
4477
4478 /* For sev guests, the memory encryption bit is not reserved in CR3. */
4479 best = kvm_find_cpuid_entry(vcpu, 0x8000001F);
4480 if (best)
4481 vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
4482
4483 if (sev_es_guest(svm->vcpu.kvm))
4484 sev_es_vcpu_after_set_cpuid(svm);
4485 }
4486
4487 static void sev_es_init_vmcb(struct vcpu_svm *svm)
4488 {
4489 struct vmcb *vmcb = svm->vmcb01.ptr;
4490 struct kvm_vcpu *vcpu = &svm->vcpu;
4491
4492 svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE;
4493
4494 /*
4495 * An SEV-ES guest requires a VMSA area that is a separate from the
4496 * VMCB page. Do not include the encryption mask on the VMSA physical
4497 * address since hardware will access it using the guest key. Note,
4498 * the VMSA will be NULL if this vCPU is the destination for intrahost
4499 * migration, and will be copied later.
4500 */
4501 if (svm->sev_es.vmsa && !svm->sev_es.snp_has_guest_vmsa)
4502 svm->vmcb->control.vmsa_pa = __pa(svm->sev_es.vmsa);
4503
4504 /* Can't intercept CR register access, HV can't modify CR registers */
4505 svm_clr_intercept(svm, INTERCEPT_CR0_READ);
4506 svm_clr_intercept(svm, INTERCEPT_CR4_READ);
4507 svm_clr_intercept(svm, INTERCEPT_CR8_READ);
4508 svm_clr_intercept(svm, INTERCEPT_CR0_WRITE);
4509 svm_clr_intercept(svm, INTERCEPT_CR4_WRITE);
4510 svm_clr_intercept(svm, INTERCEPT_CR8_WRITE);
4511
4512 svm_clr_intercept(svm, INTERCEPT_SELECTIVE_CR0);
4513
4514 /* Track EFER/CR register changes */
4515 svm_set_intercept(svm, TRAP_EFER_WRITE);
4516 svm_set_intercept(svm, TRAP_CR0_WRITE);
4517 svm_set_intercept(svm, TRAP_CR4_WRITE);
4518 svm_set_intercept(svm, TRAP_CR8_WRITE);
4519
4520 vmcb->control.intercepts[INTERCEPT_DR] = 0;
4521 if (!sev_vcpu_has_debug_swap(svm)) {
4522 vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_READ);
4523 vmcb_set_intercept(&vmcb->control, INTERCEPT_DR7_WRITE);
4524 recalc_intercepts(svm);
4525 } else {
4526 /*
4527 * Disable #DB intercept iff DebugSwap is enabled. KVM doesn't
4528 * allow debugging SEV-ES guests, and enables DebugSwap iff
4529 * NO_NESTED_DATA_BP is supported, so there's no reason to
4530 * intercept #DB when DebugSwap is enabled. For simplicity
4531 * with respect to guest debug, intercept #DB for other VMs
4532 * even if NO_NESTED_DATA_BP is supported, i.e. even if the
4533 * guest can't DoS the CPU with infinite #DB vectoring.
4534 */
4535 clr_exception_intercept(svm, DB_VECTOR);
4536 }
4537
4538 /* Can't intercept XSETBV, HV can't modify XCR0 directly */
4539 svm_clr_intercept(svm, INTERCEPT_XSETBV);
4540
4541 /* Clear intercepts on selected MSRs */
4542 set_msr_interception(vcpu, svm->msrpm, MSR_EFER, 1, 1);
4543 set_msr_interception(vcpu, svm->msrpm, MSR_IA32_CR_PAT, 1, 1);
4544 }
4545
4546 void sev_init_vmcb(struct vcpu_svm *svm)
4547 {
4548 svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;
4549 clr_exception_intercept(svm, UD_VECTOR);
4550
4551 /*
4552 * Don't intercept #GP for SEV guests, e.g. for the VMware backdoor, as
4553 * KVM can't decrypt guest memory to decode the faulting instruction.
4554 */
4555 clr_exception_intercept(svm, GP_VECTOR);
4556
4557 if (sev_es_guest(svm->vcpu.kvm))
4558 sev_es_init_vmcb(svm);
4559 }
4560
4561 void sev_es_vcpu_reset(struct vcpu_svm *svm)
4562 {
4563 struct kvm_vcpu *vcpu = &svm->vcpu;
4564 struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
4565
4566 /*
4567 * Set the GHCB MSR value as per the GHCB specification when emulating
4568 * vCPU RESET for an SEV-ES guest.
4569 */
4570 set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
4571 GHCB_VERSION_MIN,
4572 sev_enc_bit));
4573
4574 mutex_init(&svm->sev_es.snp_vmsa_mutex);
4575 }
4576
4577 void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa)
4578 {
4579 /*
4580 * All host state for SEV-ES guests is categorized into three swap types
4581 * based on how it is handled by hardware during a world switch:
4582 *
4583 * A: VMRUN: Host state saved in host save area
4584 * VMEXIT: Host state loaded from host save area
4585 *
4586 * B: VMRUN: Host state _NOT_ saved in host save area
4587 * VMEXIT: Host state loaded from host save area
4588 *
4589 * C: VMRUN: Host state _NOT_ saved in host save area
4590 * VMEXIT: Host state initialized to default(reset) values
4591 *
4592 * Manually save type-B state, i.e. state that is loaded by VMEXIT but
4593 * isn't saved by VMRUN, that isn't already saved by VMSAVE (performed
4594 * by common SVM code).
4595 */
4596 hostsa->xcr0 = kvm_host.xcr0;
4597 hostsa->pkru = read_pkru();
4598 hostsa->xss = kvm_host.xss;
4599
4600 /*
4601 * If DebugSwap is enabled, debug registers are loaded but NOT saved by
4602 * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU both
4603 * saves and loads debug registers (Type-A).
4604 */
4605 if (sev_vcpu_has_debug_swap(svm)) {
4606 hostsa->dr0 = native_get_debugreg(0);
4607 hostsa->dr1 = native_get_debugreg(1);
4608 hostsa->dr2 = native_get_debugreg(2);
4609 hostsa->dr3 = native_get_debugreg(3);
4610 hostsa->dr0_addr_mask = amd_get_dr_addr_mask(0);
4611 hostsa->dr1_addr_mask = amd_get_dr_addr_mask(1);
4612 hostsa->dr2_addr_mask = amd_get_dr_addr_mask(2);
4613 hostsa->dr3_addr_mask = amd_get_dr_addr_mask(3);
4614 }
4615 }
4616
4617 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
4618 {
4619 struct vcpu_svm *svm = to_svm(vcpu);
4620
4621 /* First SIPI: Use the values as initially set by the VMM */
4622 if (!svm->sev_es.received_first_sipi) {
4623 svm->sev_es.received_first_sipi = true;
4624 return;
4625 }
4626
4627 /* Subsequent SIPI */
4628 switch (svm->sev_es.ap_reset_hold_type) {
4629 case AP_RESET_HOLD_NAE_EVENT:
4630 /*
4631 * Return from an AP Reset Hold VMGEXIT, where the guest will
4632 * set the CS and RIP. Set SW_EXIT_INFO_2 to a non-zero value.
4633 */
4634 ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);
4635 break;
4636 case AP_RESET_HOLD_MSR_PROTO:
4637 /*
4638 * Return from an AP Reset Hold VMGEXIT, where the guest will
4639 * set the CS and RIP. Set GHCB data field to a non-zero value.
4640 */
4641 set_ghcb_msr_bits(svm, 1,
4642 GHCB_MSR_AP_RESET_HOLD_RESULT_MASK,
4643 GHCB_MSR_AP_RESET_HOLD_RESULT_POS);
4644
4645 set_ghcb_msr_bits(svm, GHCB_MSR_AP_RESET_HOLD_RESP,
4646 GHCB_MSR_INFO_MASK,
4647 GHCB_MSR_INFO_POS);
4648 break;
4649 default:
4650 break;
4651 }
4652 }
4653
4654 struct page *snp_safe_alloc_page_node(int node, gfp_t gfp)
4655 {
4656 unsigned long pfn;
4657 struct page *p;
4658
4659 if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
4660 return alloc_pages_node(node, gfp | __GFP_ZERO, 0);
4661
4662 /*
4663 * Allocate an SNP-safe page to workaround the SNP erratum where
4664 * the CPU will incorrectly signal an RMP violation #PF if a
4665 * hugepage (2MB or 1GB) collides with the RMP entry of a
4666 * 2MB-aligned VMCB, VMSA, or AVIC backing page.
4667 *
4668 * Allocate one extra page, choose a page which is not
4669 * 2MB-aligned, and free the other.
4670 */
4671 p = alloc_pages_node(node, gfp | __GFP_ZERO, 1);
4672 if (!p)
4673 return NULL;
4674
4675 split_page(p, 1);
4676
4677 pfn = page_to_pfn(p);
4678 if (IS_ALIGNED(pfn, PTRS_PER_PMD))
4679 __free_page(p++);
4680 else
4681 __free_page(p + 1);
4682
4683 return p;
4684 }
4685
4686 void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
4687 {
4688 struct kvm_memory_slot *slot;
4689 struct kvm *kvm = vcpu->kvm;
4690 int order, rmp_level, ret;
4691 bool assigned;
4692 kvm_pfn_t pfn;
4693 gfn_t gfn;
4694
4695 gfn = gpa >> PAGE_SHIFT;
4696
4697 /*
4698 * The only time RMP faults occur for shared pages is when the guest is
4699 * triggering an RMP fault for an implicit page-state change from
4700 * shared->private. Implicit page-state changes are forwarded to
4701 * userspace via KVM_EXIT_MEMORY_FAULT events, however, so RMP faults
4702 * for shared pages should not end up here.
4703 */
4704 if (!kvm_mem_is_private(kvm, gfn)) {
4705 pr_warn_ratelimited("SEV: Unexpected RMP fault for non-private GPA 0x%llx\n",
4706 gpa);
4707 return;
4708 }
4709
4710 slot = gfn_to_memslot(kvm, gfn);
4711 if (!kvm_slot_can_be_private(slot)) {
4712 pr_warn_ratelimited("SEV: Unexpected RMP fault, non-private slot for GPA 0x%llx\n",
4713 gpa);
4714 return;
4715 }
4716
4717 ret = kvm_gmem_get_pfn(kvm, slot, gfn, &pfn, &order);
4718 if (ret) {
4719 pr_warn_ratelimited("SEV: Unexpected RMP fault, no backing page for private GPA 0x%llx\n",
4720 gpa);
4721 return;
4722 }
4723
4724 ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
4725 if (ret || !assigned) {
4726 pr_warn_ratelimited("SEV: Unexpected RMP fault, no assigned RMP entry found for GPA 0x%llx PFN 0x%llx error %d\n",
4727 gpa, pfn, ret);
4728 goto out_no_trace;
4729 }
4730
4731 /*
4732 * There are 2 cases where a PSMASH may be needed to resolve an #NPF
4733 * with PFERR_GUEST_RMP_BIT set:
4734 *
4735 * 1) RMPADJUST/PVALIDATE can trigger an #NPF with PFERR_GUEST_SIZEM
4736 * bit set if the guest issues them with a smaller granularity than
4737 * what is indicated by the page-size bit in the 2MB RMP entry for
4738 * the PFN that backs the GPA.
4739 *
4740 * 2) Guest access via NPT can trigger an #NPF if the NPT mapping is
4741 * smaller than what is indicated by the 2MB RMP entry for the PFN
4742 * that backs the GPA.
4743 *
4744 * In both these cases, the corresponding 2M RMP entry needs to
4745 * be PSMASH'd to 512 4K RMP entries. If the RMP entry is already
4746 * split into 4K RMP entries, then this is likely a spurious case which
4747 * can occur when there are concurrent accesses by the guest to a 2MB
4748 * GPA range that is backed by a 2MB-aligned PFN who's RMP entry is in
4749 * the process of being PMASH'd into 4K entries. These cases should
4750 * resolve automatically on subsequent accesses, so just ignore them
4751 * here.
4752 */
4753 if (rmp_level == PG_LEVEL_4K)
4754 goto out;
4755
4756 ret = snp_rmptable_psmash(pfn);
4757 if (ret) {
4758 /*
4759 * Look it up again. If it's 4K now then the PSMASH may have
4760 * raced with another process and the issue has already resolved
4761 * itself.
4762 */
4763 if (!snp_lookup_rmpentry(pfn, &assigned, &rmp_level) &&
4764 assigned && rmp_level == PG_LEVEL_4K)
4765 goto out;
4766
4767 pr_warn_ratelimited("SEV: Unable to split RMP entry for GPA 0x%llx PFN 0x%llx ret %d\n",
4768 gpa, pfn, ret);
4769 }
4770
4771 kvm_zap_gfn_range(kvm, gfn, gfn + PTRS_PER_PMD);
4772 out:
4773 trace_kvm_rmp_fault(vcpu, gpa, pfn, error_code, rmp_level, ret);
4774 out_no_trace:
4775 put_page(pfn_to_page(pfn));
4776 }
4777
4778 static bool is_pfn_range_shared(kvm_pfn_t start, kvm_pfn_t end)
4779 {
4780 kvm_pfn_t pfn = start;
4781
4782 while (pfn < end) {
4783 int ret, rmp_level;
4784 bool assigned;
4785
4786 ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
4787 if (ret) {
4788 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",
4789 pfn, start, end, rmp_level, ret);
4790 return false;
4791 }
4792
4793 if (assigned) {
4794 pr_debug("%s: overlap detected, PFN 0x%llx start 0x%llx end 0x%llx RMP level %d\n",
4795 __func__, pfn, start, end, rmp_level);
4796 return false;
4797 }
4798
4799 pfn++;
4800 }
4801
4802 return true;
4803 }
4804
4805 static u8 max_level_for_order(int order)
4806 {
4807 if (order >= KVM_HPAGE_GFN_SHIFT(PG_LEVEL_2M))
4808 return PG_LEVEL_2M;
4809
4810 return PG_LEVEL_4K;
4811 }
4812
4813 static bool is_large_rmp_possible(struct kvm *kvm, kvm_pfn_t pfn, int order)
4814 {
4815 kvm_pfn_t pfn_aligned = ALIGN_DOWN(pfn, PTRS_PER_PMD);
4816
4817 /*
4818 * If this is a large folio, and the entire 2M range containing the
4819 * PFN is currently shared, then the entire 2M-aligned range can be
4820 * set to private via a single 2M RMP entry.
4821 */
4822 if (max_level_for_order(order) > PG_LEVEL_4K &&
4823 is_pfn_range_shared(pfn_aligned, pfn_aligned + PTRS_PER_PMD))
4824 return true;
4825
4826 return false;
4827 }
4828
4829 int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)
4830 {
4831 struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
4832 kvm_pfn_t pfn_aligned;
4833 gfn_t gfn_aligned;
4834 int level, rc;
4835 bool assigned;
4836
4837 if (!sev_snp_guest(kvm))
4838 return 0;
4839
4840 rc = snp_lookup_rmpentry(pfn, &assigned, &level);
4841 if (rc) {
4842 pr_err_ratelimited("SEV: Failed to look up RMP entry: GFN %llx PFN %llx error %d\n",
4843 gfn, pfn, rc);
4844 return -ENOENT;
4845 }
4846
4847 if (assigned) {
4848 pr_debug("%s: already assigned: gfn %llx pfn %llx max_order %d level %d\n",
4849 __func__, gfn, pfn, max_order, level);
4850 return 0;
4851 }
4852
4853 if (is_large_rmp_possible(kvm, pfn, max_order)) {
4854 level = PG_LEVEL_2M;
4855 pfn_aligned = ALIGN_DOWN(pfn, PTRS_PER_PMD);
4856 gfn_aligned = ALIGN_DOWN(gfn, PTRS_PER_PMD);
4857 } else {
4858 level = PG_LEVEL_4K;
4859 pfn_aligned = pfn;
4860 gfn_aligned = gfn;
4861 }
4862
4863 rc = rmp_make_private(pfn_aligned, gfn_to_gpa(gfn_aligned), level, sev->asid, false);
4864 if (rc) {
4865 pr_err_ratelimited("SEV: Failed to update RMP entry: GFN %llx PFN %llx level %d error %d\n",
4866 gfn, pfn, level, rc);
4867 return -EINVAL;
4868 }
4869
4870 pr_debug("%s: updated: gfn %llx pfn %llx pfn_aligned %llx max_order %d level %d\n",
4871 __func__, gfn, pfn, pfn_aligned, max_order, level);
4872
4873 return 0;
4874 }
4875
4876 void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end)
4877 {
4878 kvm_pfn_t pfn;
4879
4880 if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
4881 return;
4882
4883 pr_debug("%s: PFN start 0x%llx PFN end 0x%llx\n", __func__, start, end);
4884
4885 for (pfn = start; pfn < end;) {
4886 bool use_2m_update = false;
4887 int rc, rmp_level;
4888 bool assigned;
4889
4890 rc = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
4891 if (rc || !assigned)
4892 goto next_pfn;
4893
4894 use_2m_update = IS_ALIGNED(pfn, PTRS_PER_PMD) &&
4895 end >= (pfn + PTRS_PER_PMD) &&
4896 rmp_level > PG_LEVEL_4K;
4897
4898 /*
4899 * If an unaligned PFN corresponds to a 2M region assigned as a
4900 * large page in the RMP table, PSMASH the region into individual
4901 * 4K RMP entries before attempting to convert a 4K sub-page.
4902 */
4903 if (!use_2m_update && rmp_level > PG_LEVEL_4K) {
4904 /*
4905 * This shouldn't fail, but if it does, report it, but
4906 * still try to update RMP entry to shared and pray this
4907 * was a spurious error that can be addressed later.
4908 */
4909 rc = snp_rmptable_psmash(pfn);
4910 WARN_ONCE(rc, "SEV: Failed to PSMASH RMP entry for PFN 0x%llx error %d\n",
4911 pfn, rc);
4912 }
4913
4914 rc = rmp_make_shared(pfn, use_2m_update ? PG_LEVEL_2M : PG_LEVEL_4K);
4915 if (WARN_ONCE(rc, "SEV: Failed to update RMP entry for PFN 0x%llx error %d\n",
4916 pfn, rc))
4917 goto next_pfn;
4918
4919 /*
4920 * SEV-ES avoids host/guest cache coherency issues through
4921 * WBINVD hooks issued via MMU notifiers during run-time, and
4922 * KVM's VM destroy path at shutdown. Those MMU notifier events
4923 * don't cover gmem since there is no requirement to map pages
4924 * to a HVA in order to use them for a running guest. While the
4925 * shutdown path would still likely cover things for SNP guests,
4926 * userspace may also free gmem pages during run-time via
4927 * hole-punching operations on the guest_memfd, so flush the
4928 * cache entries for these pages before free'ing them back to
4929 * the host.
4930 */
4931 clflush_cache_range(__va(pfn_to_hpa(pfn)),
4932 use_2m_update ? PMD_SIZE : PAGE_SIZE);
4933 next_pfn:
4934 pfn += use_2m_update ? PTRS_PER_PMD : 1;
4935 cond_resched();
4936 }
4937 }
4938
4939 int sev_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn)
4940 {
4941 int level, rc;
4942 bool assigned;
4943
4944 if (!sev_snp_guest(kvm))
4945 return 0;
4946
4947 rc = snp_lookup_rmpentry(pfn, &assigned, &level);
4948 if (rc || !assigned)
4949 return PG_LEVEL_4K;
4950
4951 return level;
4952 }
4953
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