diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8351c4d00ac0faf5661a9b0ebcaf10a9ed1309b0..548b97d284d3814317a620af55f258920b3a7838 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -261,6 +261,7 @@ struct kvm_mmu { union kvm_mmu_page_role base_role; u64 *pae_root; + u64 rsvd_bits_mask[2][4]; }; struct kvm_vcpu_arch { @@ -791,5 +792,6 @@ asmlinkage void kvm_handle_fault_on_reboot(void); #define KVM_ARCH_WANT_MMU_NOTIFIER int kvm_unmap_hva(struct kvm *kvm, unsigned long hva); int kvm_age_hva(struct kvm *kvm, unsigned long hva); +int cpuid_maxphyaddr(struct kvm_vcpu *vcpu); #endif /* _ASM_X86_KVM_HOST_H */ diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 8aac67cbd92f0ee364ffb4dd5534d964c9b69a20..b2c8e28021c953edf87ce6235e293903ef0f5932 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -126,6 +126,7 @@ module_param(oos_shadow, bool, 0644); #define PFERR_PRESENT_MASK (1U << 0) #define PFERR_WRITE_MASK (1U << 1) #define PFERR_USER_MASK (1U << 2) +#define PFERR_RSVD_MASK (1U << 3) #define PFERR_FETCH_MASK (1U << 4) #define PT_DIRECTORY_LEVEL 2 @@ -179,6 +180,11 @@ static u64 __read_mostly shadow_accessed_mask; static u64 __read_mostly shadow_dirty_mask; static u64 __read_mostly shadow_mt_mask; +static inline u64 rsvd_bits(int s, int e) +{ + return ((1ULL << (e - s + 1)) - 1) << s; +} + void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte) { shadow_trap_nonpresent_pte = trap_pte; @@ -2151,6 +2157,14 @@ static void paging_free(struct kvm_vcpu *vcpu) nonpaging_free(vcpu); } +static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level) +{ + int bit7; + + bit7 = (gpte >> 7) & 1; + return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0; +} + #define PTTYPE 64 #include "paging_tmpl.h" #undef PTTYPE @@ -2159,6 +2173,55 @@ static void paging_free(struct kvm_vcpu *vcpu) #include "paging_tmpl.h" #undef PTTYPE +static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level) +{ + struct kvm_mmu *context = &vcpu->arch.mmu; + int maxphyaddr = cpuid_maxphyaddr(vcpu); + u64 exb_bit_rsvd = 0; + + if (!is_nx(vcpu)) + exb_bit_rsvd = rsvd_bits(63, 63); + switch (level) { + case PT32_ROOT_LEVEL: + /* no rsvd bits for 2 level 4K page table entries */ + context->rsvd_bits_mask[0][1] = 0; + context->rsvd_bits_mask[0][0] = 0; + if (is_cpuid_PSE36()) + /* 36bits PSE 4MB page */ + context->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); + else + /* 32 bits PSE 4MB page */ + context->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); + context->rsvd_bits_mask[1][0] = ~0ull; + break; + case PT32E_ROOT_LEVEL: + context->rsvd_bits_mask[0][1] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 62); /* PDE */ + context->rsvd_bits_mask[0][0] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 62); /* PTE */ + context->rsvd_bits_mask[1][1] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 62) | + rsvd_bits(13, 20); /* large page */ + context->rsvd_bits_mask[1][0] = ~0ull; + break; + case PT64_ROOT_LEVEL: + context->rsvd_bits_mask[0][3] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); + context->rsvd_bits_mask[0][2] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); + context->rsvd_bits_mask[0][1] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); + context->rsvd_bits_mask[0][0] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 51); + context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3]; + context->rsvd_bits_mask[1][2] = context->rsvd_bits_mask[0][2]; + context->rsvd_bits_mask[1][1] = exb_bit_rsvd | + rsvd_bits(maxphyaddr, 51) | rsvd_bits(13, 20); + context->rsvd_bits_mask[1][0] = ~0ull; + break; + } +} + static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) { struct kvm_mmu *context = &vcpu->arch.mmu; @@ -2179,6 +2242,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) static int paging64_init_context(struct kvm_vcpu *vcpu) { + reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL); return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL); } @@ -2186,6 +2250,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu) { struct kvm_mmu *context = &vcpu->arch.mmu; + reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL); context->new_cr3 = paging_new_cr3; context->page_fault = paging32_page_fault; context->gva_to_gpa = paging32_gva_to_gpa; @@ -2201,6 +2266,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu) static int paging32E_init_context(struct kvm_vcpu *vcpu) { + reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL); return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL); } @@ -2221,12 +2287,15 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->gva_to_gpa = nonpaging_gva_to_gpa; context->root_level = 0; } else if (is_long_mode(vcpu)) { + reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL); context->gva_to_gpa = paging64_gva_to_gpa; context->root_level = PT64_ROOT_LEVEL; } else if (is_pae(vcpu)) { + reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL); context->gva_to_gpa = paging64_gva_to_gpa; context->root_level = PT32E_ROOT_LEVEL; } else { + reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL); context->gva_to_gpa = paging32_gva_to_gpa; context->root_level = PT32_ROOT_LEVEL; } diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index eae949973d09c193003bfdb725ca57bc7acffcd0..09782a982785d332ab5f697c5bab923d203ffa08 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -123,6 +123,7 @@ static int FNAME(walk_addr)(struct guest_walker *walker, gfn_t table_gfn; unsigned index, pt_access, pte_access; gpa_t pte_gpa; + int rsvd_fault = 0; pgprintk("%s: addr %lx\n", __func__, addr); walk: @@ -157,6 +158,10 @@ static int FNAME(walk_addr)(struct guest_walker *walker, if (!is_present_pte(pte)) goto not_present; + rsvd_fault = is_rsvd_bits_set(vcpu, pte, walker->level); + if (rsvd_fault) + goto access_error; + if (write_fault && !is_writeble_pte(pte)) if (user_fault || is_write_protection(vcpu)) goto access_error; @@ -232,6 +237,8 @@ static int FNAME(walk_addr)(struct guest_walker *walker, walker->error_code |= PFERR_USER_MASK; if (fetch_fault) walker->error_code |= PFERR_FETCH_MASK; + if (rsvd_fault) + walker->error_code |= PFERR_RSVD_MASK; return 0; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5bbcad345376e4b8ed3f170b81575a8bf59805a7..df866684bad1f99eb0f28ecfdca0b0b83402a7a8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3017,6 +3017,16 @@ struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, return best; } +int cpuid_maxphyaddr(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); + if (best) + return best->eax & 0xff; + return 36; +} + void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) { u32 function, index;