diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 61 | ||||
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 25 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 19 |
4 files changed, 95 insertions, 14 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f5df0a84e51c..c0efd16bdfa1 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -286,6 +286,7 @@ struct kvm_mmu { u64 *pae_root; u64 *lm_root; u64 rsvd_bits_mask[2][4]; + u64 bad_mt_xwr; /* * Bitmap: bit set = last pte in walk @@ -512,6 +513,9 @@ struct kvm_vcpu_arch { * instruction. */ bool write_fault_to_shadow_pgtable; + + /* set at EPT violation at this point */ + unsigned long exit_qualification; }; struct kvm_lpage_info { diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 75d843bb4ca3..a215c41b5176 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3519,6 +3519,8 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int maxphyaddr = cpuid_maxphyaddr(vcpu); u64 exb_bit_rsvd = 0; + context->bad_mt_xwr = 0; + if (!context->nx) exb_bit_rsvd = rsvd_bits(63, 63); switch (context->root_level) { @@ -3574,7 +3576,40 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, } } -static void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) +static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, + struct kvm_mmu *context, bool execonly) +{ + int maxphyaddr = cpuid_maxphyaddr(vcpu); + int pte; + + context->rsvd_bits_mask[0][3] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 7); + context->rsvd_bits_mask[0][2] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 6); + context->rsvd_bits_mask[0][1] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 6); + context->rsvd_bits_mask[0][0] = rsvd_bits(maxphyaddr, 51); + + /* large page */ + context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3]; + context->rsvd_bits_mask[1][2] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 29); + context->rsvd_bits_mask[1][1] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 20); + context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[0][0]; + + for (pte = 0; pte < 64; pte++) { + int rwx_bits = pte & 7; + int mt = pte >> 3; + if (mt == 0x2 || mt == 0x3 || mt == 0x7 || + rwx_bits == 0x2 || rwx_bits == 0x6 || + (rwx_bits == 0x4 && !execonly)) + context->bad_mt_xwr |= (1ull << pte); + } +} + +static void update_permission_bitmask(struct kvm_vcpu *vcpu, + struct kvm_mmu *mmu, bool ept) { unsigned bit, byte, pfec; u8 map; @@ -3592,12 +3627,16 @@ static void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu w = bit & ACC_WRITE_MASK; u = bit & ACC_USER_MASK; - /* Not really needed: !nx will cause pte.nx to fault */ - x |= !mmu->nx; - /* Allow supervisor writes if !cr0.wp */ - w |= !is_write_protection(vcpu) && !uf; - /* Disallow supervisor fetches of user code if cr4.smep */ - x &= !(smep && u && !uf); + if (!ept) { + /* Not really needed: !nx will cause pte.nx to fault */ + x |= !mmu->nx; + /* Allow supervisor writes if !cr0.wp */ + w |= !is_write_protection(vcpu) && !uf; + /* Disallow supervisor fetches of user code if cr4.smep */ + x &= !(smep && u && !uf); + } else + /* Not really needed: no U/S accesses on ept */ + u = 1; fault = (ff && !x) || (uf && !u) || (wf && !w); map |= fault << bit; @@ -3632,7 +3671,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, context->root_level = level; reset_rsvds_bits_mask(vcpu, context); - update_permission_bitmask(vcpu, context); + update_permission_bitmask(vcpu, context, false); update_last_pte_bitmap(vcpu, context); ASSERT(is_pae(vcpu)); @@ -3662,7 +3701,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu, context->root_level = PT32_ROOT_LEVEL; reset_rsvds_bits_mask(vcpu, context); - update_permission_bitmask(vcpu, context); + update_permission_bitmask(vcpu, context, false); update_last_pte_bitmap(vcpu, context); context->new_cr3 = paging_new_cr3; @@ -3724,7 +3763,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->gva_to_gpa = paging32_gva_to_gpa; } - update_permission_bitmask(vcpu, context); + update_permission_bitmask(vcpu, context, false); update_last_pte_bitmap(vcpu, context); return 0; @@ -3803,7 +3842,7 @@ static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu) g_context->gva_to_gpa = paging32_gva_to_gpa_nested; } - update_permission_bitmask(vcpu, g_context); + update_permission_bitmask(vcpu, g_context, false); update_last_pte_bitmap(vcpu, g_context); return 0; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 50b8679d4dd8..043330159179 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -129,10 +129,10 @@ static inline void FNAME(protect_clean_gpte)(unsigned *access, unsigned gpte) static bool FNAME(is_rsvd_bits_set)(struct kvm_mmu *mmu, u64 gpte, int level) { - int bit7; + int bit7 = (gpte >> 7) & 1, low6 = gpte & 0x3f; - bit7 = (gpte >> 7) & 1; - return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) != 0; + return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) | + ((mmu->bad_mt_xwr & (1ull << low6)) != 0); } static inline int FNAME(is_present_gpte)(unsigned long pte) @@ -386,6 +386,25 @@ error: walker->fault.vector = PF_VECTOR; walker->fault.error_code_valid = true; walker->fault.error_code = errcode; + +#if PTTYPE == PTTYPE_EPT + /* + * Use PFERR_RSVD_MASK in error_code to to tell if EPT + * misconfiguration requires to be injected. The detection is + * done by is_rsvd_bits_set() above. + * + * We set up the value of exit_qualification to inject: + * [2:0] - Derive from [2:0] of real exit_qualification at EPT violation + * [5:3] - Calculated by the page walk of the guest EPT page tables + * [7:8] - Derived from [7:8] of real exit_qualification + * + * The other bits are set to 0. + */ + if (!(errcode & PFERR_RSVD_MASK)) { + vcpu->arch.exit_qualification &= 0x187; + vcpu->arch.exit_qualification |= ((pt_access & pte) & 0x7) << 3; + } +#endif walker->fault.address = addr; walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e3c8e28aeb35..0d18ed31671c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5317,9 +5317,13 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu) /* It is a write fault? */ error_code = exit_qualification & (1U << 1); + /* It is a fetch fault? */ + error_code |= (exit_qualification & (1U << 2)) << 2; /* ept page table is present? */ error_code |= (exit_qualification >> 3) & 0x1; + vcpu->arch.exit_qualification = exit_qualification; + return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0); } @@ -7348,6 +7352,21 @@ static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry) entry->ecx |= bit(X86_FEATURE_VMX); } +static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu, + struct x86_exception *fault) +{ + struct vmcs12 *vmcs12; + nested_vmx_vmexit(vcpu); + vmcs12 = get_vmcs12(vcpu); + + if (fault->error_code & PFERR_RSVD_MASK) + vmcs12->vm_exit_reason = EXIT_REASON_EPT_MISCONFIG; + else + vmcs12->vm_exit_reason = EXIT_REASON_EPT_VIOLATION; + vmcs12->exit_qualification = vcpu->arch.exit_qualification; + vmcs12->guest_physical_address = fault->address; +} + /* * prepare_vmcs02 is called when the L1 guest hypervisor runs its nested * L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it |