1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * Copyright (C) 2020-2023 Loongson Technology !! 2 * This file is subject to the terms and conditions of the GNU General Public
>> 3 * License. See the file "COPYING" in the main directory of this archive
>> 4 * for more details.
>> 5 *
>> 6 * KVM/MIPS TLB handling, this file is part of the Linux host kernel so that
>> 7 * TLB handlers run from KSEG0
>> 8 *
>> 9 * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
>> 10 * Authors: Sanjay Lal <sanjayl@kymasys.com>
4 */ 11 */
5 12
>> 13 #include <linux/sched.h>
>> 14 #include <linux/smp.h>
>> 15 #include <linux/mm.h>
>> 16 #include <linux/delay.h>
>> 17 #include <linux/export.h>
6 #include <linux/kvm_host.h> 18 #include <linux/kvm_host.h>
>> 19 #include <linux/srcu.h>
>> 20
>> 21 #include <asm/cpu.h>
>> 22 #include <asm/bootinfo.h>
>> 23 #include <asm/mmu_context.h>
>> 24 #include <asm/pgtable.h>
>> 25 #include <asm/cacheflush.h>
7 #include <asm/tlb.h> 26 #include <asm/tlb.h>
8 #include <asm/kvm_csr.h> !! 27 #include <asm/tlbdebug.h>
9 28
10 /* !! 29 #undef CONFIG_MIPS_MT
11 * kvm_flush_tlb_all() - Flush all root TLB en !! 30 #include <asm/r4kcache.h>
12 * !! 31 #define CONFIG_MIPS_MT
13 * Invalidate all entries including GVA-->GPA !! 32
14 */ !! 33 #define KVM_GUEST_PC_TLB 0
15 void kvm_flush_tlb_all(void) !! 34 #define KVM_GUEST_SP_TLB 1
>> 35
>> 36 static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
>> 37 {
>> 38 struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
>> 39 int cpu = smp_processor_id();
>> 40
>> 41 return cpu_asid(cpu, kern_mm);
>> 42 }
>> 43
>> 44 static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
>> 45 {
>> 46 struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
>> 47 int cpu = smp_processor_id();
>> 48
>> 49 return cpu_asid(cpu, user_mm);
>> 50 }
>> 51
>> 52 /* Structure defining an tlb entry data set. */
>> 53
>> 54 void kvm_mips_dump_host_tlbs(void)
16 { 55 {
17 unsigned long flags; 56 unsigned long flags;
18 57
19 local_irq_save(flags); 58 local_irq_save(flags);
20 invtlb_all(INVTLB_ALLGID, 0, 0); !! 59
>> 60 kvm_info("HOST TLBs:\n");
>> 61 dump_tlb_regs();
>> 62 pr_info("\n");
>> 63 dump_tlb_all();
>> 64
>> 65 local_irq_restore(flags);
>> 66 }
>> 67 EXPORT_SYMBOL_GPL(kvm_mips_dump_host_tlbs);
>> 68
>> 69 void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
>> 70 {
>> 71 struct mips_coproc *cop0 = vcpu->arch.cop0;
>> 72 struct kvm_mips_tlb tlb;
>> 73 int i;
>> 74
>> 75 kvm_info("Guest TLBs:\n");
>> 76 kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
>> 77
>> 78 for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
>> 79 tlb = vcpu->arch.guest_tlb[i];
>> 80 kvm_info("TLB%c%3d Hi 0x%08lx ",
>> 81 (tlb.tlb_lo[0] | tlb.tlb_lo[1]) & ENTRYLO_V
>> 82 ? ' ' : '*',
>> 83 i, tlb.tlb_hi);
>> 84 kvm_info("Lo0=0x%09llx %c%c attr %lx ",
>> 85 (u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[0]),
>> 86 (tlb.tlb_lo[0] & ENTRYLO_D) ? 'D' : ' ',
>> 87 (tlb.tlb_lo[0] & ENTRYLO_G) ? 'G' : ' ',
>> 88 (tlb.tlb_lo[0] & ENTRYLO_C) >> ENTRYLO_C_SHIFT);
>> 89 kvm_info("Lo1=0x%09llx %c%c attr %lx sz=%lx\n",
>> 90 (u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[1]),
>> 91 (tlb.tlb_lo[1] & ENTRYLO_D) ? 'D' : ' ',
>> 92 (tlb.tlb_lo[1] & ENTRYLO_G) ? 'G' : ' ',
>> 93 (tlb.tlb_lo[1] & ENTRYLO_C) >> ENTRYLO_C_SHIFT,
>> 94 tlb.tlb_mask);
>> 95 }
>> 96 }
>> 97 EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
>> 98
>> 99 int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
>> 100 {
>> 101 int i;
>> 102 int index = -1;
>> 103 struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
>> 104
>> 105 for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
>> 106 if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
>> 107 TLB_HI_ASID_HIT(tlb[i], entryhi)) {
>> 108 index = i;
>> 109 break;
>> 110 }
>> 111 }
>> 112
>> 113 kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
>> 114 __func__, entryhi, index, tlb[i].tlb_lo[0], tlb[i].tlb_lo[1]);
>> 115
>> 116 return index;
>> 117 }
>> 118 EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
>> 119
>> 120 static int _kvm_mips_host_tlb_inv(unsigned long entryhi)
>> 121 {
>> 122 int idx;
>> 123
>> 124 write_c0_entryhi(entryhi);
>> 125 mtc0_tlbw_hazard();
>> 126
>> 127 tlb_probe();
>> 128 tlb_probe_hazard();
>> 129 idx = read_c0_index();
>> 130
>> 131 if (idx >= current_cpu_data.tlbsize)
>> 132 BUG();
>> 133
>> 134 if (idx >= 0) {
>> 135 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
>> 136 write_c0_entrylo0(0);
>> 137 write_c0_entrylo1(0);
>> 138 mtc0_tlbw_hazard();
>> 139
>> 140 tlb_write_indexed();
>> 141 tlbw_use_hazard();
>> 142 }
>> 143
>> 144 return idx;
>> 145 }
>> 146
>> 147 int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va,
>> 148 bool user, bool kernel)
>> 149 {
>> 150 /*
>> 151 * Initialize idx_user and idx_kernel to workaround bogus
>> 152 * maybe-initialized warning when using GCC 6.
>> 153 */
>> 154 int idx_user = 0, idx_kernel = 0;
>> 155 unsigned long flags, old_entryhi;
>> 156
>> 157 local_irq_save(flags);
>> 158
>> 159 old_entryhi = read_c0_entryhi();
>> 160
>> 161 if (user)
>> 162 idx_user = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
>> 163 kvm_mips_get_user_asid(vcpu));
>> 164 if (kernel)
>> 165 idx_kernel = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
>> 166 kvm_mips_get_kernel_asid(vcpu));
>> 167
>> 168 write_c0_entryhi(old_entryhi);
>> 169 mtc0_tlbw_hazard();
>> 170
21 local_irq_restore(flags); 171 local_irq_restore(flags);
>> 172
>> 173 if (user && idx_user >= 0)
>> 174 kvm_debug("%s: Invalidated guest user entryhi %#lx @ idx %d\n",
>> 175 __func__, (va & VPN2_MASK) |
>> 176 kvm_mips_get_user_asid(vcpu), idx_user);
>> 177 if (kernel && idx_kernel >= 0)
>> 178 kvm_debug("%s: Invalidated guest kernel entryhi %#lx @ idx %d\n",
>> 179 __func__, (va & VPN2_MASK) |
>> 180 kvm_mips_get_kernel_asid(vcpu), idx_kernel);
>> 181
>> 182 return 0;
22 } 183 }
>> 184 EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
23 185
24 void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, !! 186 /**
>> 187 * kvm_mips_suspend_mm() - Suspend the active mm.
>> 188 * @cpu The CPU we're running on.
>> 189 *
>> 190 * Suspend the active_mm, ready for a switch to a KVM guest virtual address
>> 191 * space. This is left active for the duration of guest context, including time
>> 192 * with interrupts enabled, so we need to be careful not to confuse e.g. cache
>> 193 * management IPIs.
>> 194 *
>> 195 * kvm_mips_resume_mm() should be called before context switching to a different
>> 196 * process so we don't need to worry about reference counting.
>> 197 *
>> 198 * This needs to be in static kernel code to avoid exporting init_mm.
>> 199 */
>> 200 void kvm_mips_suspend_mm(int cpu)
>> 201 {
>> 202 cpumask_clear_cpu(cpu, mm_cpumask(current->active_mm));
>> 203 current->active_mm = &init_mm;
>> 204 }
>> 205 EXPORT_SYMBOL_GPL(kvm_mips_suspend_mm);
>> 206
>> 207 /**
>> 208 * kvm_mips_resume_mm() - Resume the current process mm.
>> 209 * @cpu The CPU we're running on.
>> 210 *
>> 211 * Resume the mm of the current process, after a switch back from a KVM guest
>> 212 * virtual address space (see kvm_mips_suspend_mm()).
>> 213 */
>> 214 void kvm_mips_resume_mm(int cpu)
25 { 215 {
26 lockdep_assert_irqs_disabled(); !! 216 cpumask_set_cpu(cpu, mm_cpumask(current->mm));
27 gpa &= (PAGE_MASK << 1); !! 217 current->active_mm = current->mm;
28 invtlb(INVTLB_GID_ADDR, read_csr_gstat <<
29 } 218 }
>> 219 EXPORT_SYMBOL_GPL(kvm_mips_resume_mm);
30 220
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.