diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 49 |
1 files changed, 26 insertions, 23 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 931467881da..76398fe15df 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -199,16 +199,20 @@ void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask) EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask); /* - * spte bits of bit 3 ~ bit 11 are used as low 9 bits of generation number, - * the bits of bits 52 ~ bit 61 are used as high 10 bits of generation - * number. + * the low bit of the generation number is always presumed to be zero. + * This disables mmio caching during memslot updates. The concept is + * similar to a seqcount but instead of retrying the access we just punt + * and ignore the cache. + * + * spte bits 3-11 are used as bits 1-9 of the generation number, + * the bits 52-61 are used as bits 10-19 of the generation number. */ -#define MMIO_SPTE_GEN_LOW_SHIFT 3 +#define MMIO_SPTE_GEN_LOW_SHIFT 2 #define MMIO_SPTE_GEN_HIGH_SHIFT 52 -#define MMIO_GEN_SHIFT 19 -#define MMIO_GEN_LOW_SHIFT 9 -#define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 1) +#define MMIO_GEN_SHIFT 20 +#define MMIO_GEN_LOW_SHIFT 10 +#define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 2) #define MMIO_GEN_MASK ((1 << MMIO_GEN_SHIFT) - 1) #define MMIO_MAX_GEN ((1 << MMIO_GEN_SHIFT) - 1) @@ -236,12 +240,7 @@ static unsigned int get_mmio_spte_generation(u64 spte) static unsigned int kvm_current_mmio_generation(struct kvm *kvm) { - /* - * Init kvm generation close to MMIO_MAX_GEN to easily test the - * code of handling generation number wrap-around. - */ - return (kvm_memslots(kvm)->generation + - MMIO_MAX_GEN - 150) & MMIO_GEN_MASK; + return kvm_memslots(kvm)->generation & MMIO_GEN_MASK; } static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn, @@ -296,11 +295,6 @@ static bool check_mmio_spte(struct kvm *kvm, u64 spte) return likely(kvm_gen == spte_gen); } -static inline u64 rsvd_bits(int s, int e) -{ - return ((1ULL << (e - s + 1)) - 1) << s; -} - void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, u64 dirty_mask, u64 nx_mask, u64 x_mask) { @@ -3163,7 +3157,7 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) return; - vcpu_clear_mmio_info(vcpu, ~0ul); + vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY); kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC); if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) { hpa_t root = vcpu->arch.mmu.root_hpa; @@ -3206,7 +3200,7 @@ static gpa_t nonpaging_gva_to_gpa_nested(struct kvm_vcpu *vcpu, gva_t vaddr, { if (exception) exception->error_code = 0; - return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, access); + return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, access, exception); } static bool quickly_check_mmio_pf(struct kvm_vcpu *vcpu, u64 addr, bool direct) @@ -3518,6 +3512,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int maxphyaddr = cpuid_maxphyaddr(vcpu); u64 exb_bit_rsvd = 0; u64 gbpages_bit_rsvd = 0; + u64 nonleaf_bit8_rsvd = 0; context->bad_mt_xwr = 0; @@ -3525,6 +3520,14 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, exb_bit_rsvd = rsvd_bits(63, 63); if (!guest_cpuid_has_gbpages(vcpu)) gbpages_bit_rsvd = rsvd_bits(7, 7); + + /* + * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for + * leaf entries) on AMD CPUs only. + */ + if (guest_cpuid_is_amd(vcpu)) + nonleaf_bit8_rsvd = rsvd_bits(8, 8); + switch (context->root_level) { case PT32_ROOT_LEVEL: /* no rsvd bits for 2 level 4K page table entries */ @@ -3559,9 +3562,9 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, break; case PT64_ROOT_LEVEL: context->rsvd_bits_mask[0][3] = exb_bit_rsvd | - rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7); + nonleaf_bit8_rsvd | rsvd_bits(7, 7) | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][2] = exb_bit_rsvd | - gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51); + nonleaf_bit8_rsvd | gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][1] = exb_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][0] = exb_bit_rsvd | @@ -4433,7 +4436,7 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm) * The very rare case: if the generation-number is round, * zap all shadow pages. */ - if (unlikely(kvm_current_mmio_generation(kvm) >= MMIO_MAX_GEN)) { + if (unlikely(kvm_current_mmio_generation(kvm) == 0)) { printk_ratelimited(KERN_INFO "kvm: zapping shadow pages for mmio generation wraparound\n"); kvm_mmu_invalidate_zap_all_pages(kvm); } |