diff options
Diffstat (limited to 'arch/x86/kvm/mmu.h')
| -rw-r--r-- | arch/x86/kvm/mmu.h | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index bf8dbc4bb12a..e6cae6f22683 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -214,27 +214,27 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, */ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned pte_access, unsigned pte_pkey, - unsigned pfec) + u64 access) { - int cpl = static_call(kvm_x86_get_cpl)(vcpu); + /* strip nested paging fault error codes */ + unsigned int pfec = access; unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu); /* - * If CPL < 3, SMAP prevention are disabled if EFLAGS.AC = 1. + * For explicit supervisor accesses, SMAP is disabled if EFLAGS.AC = 1. + * For implicit supervisor accesses, SMAP cannot be overridden. * - * If CPL = 3, SMAP applies to all supervisor-mode data accesses - * (these are implicit supervisor accesses) regardless of the value - * of EFLAGS.AC. + * SMAP works on supervisor accesses only, and not_smap can + * be set or not set when user access with neither has any bearing + * on the result. * - * This computes (cpl < 3) && (rflags & X86_EFLAGS_AC), leaving - * the result in X86_EFLAGS_AC. We then insert it in place of - * the PFERR_RSVD_MASK bit; this bit will always be zero in pfec, - * but it will be one in index if SMAP checks are being overridden. - * It is important to keep this branchless. + * We put the SMAP checking bit in place of the PFERR_RSVD_MASK bit; + * this bit will always be zero in pfec, but it will be one in index + * if SMAP checks are being disabled. */ - unsigned long smap = (cpl - 3) & (rflags & X86_EFLAGS_AC); - int index = (pfec >> 1) + - (smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1)); + u64 implicit_access = access & PFERR_IMPLICIT_ACCESS; + bool not_smap = ((rflags & X86_EFLAGS_AC) | implicit_access) == X86_EFLAGS_AC; + int index = (pfec + (not_smap << PFERR_RSVD_BIT)) >> 1; bool fault = (mmu->permissions[index] >> pte_access) & 1; u32 errcode = PFERR_PRESENT_MASK; @@ -317,12 +317,12 @@ static inline void kvm_update_page_stats(struct kvm *kvm, int level, int count) atomic64_add(count, &kvm->stat.pages[level - 1]); } -gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access, +gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u64 access, struct x86_exception *exception); static inline gpa_t kvm_translate_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, - gpa_t gpa, u32 access, + gpa_t gpa, u64 access, struct x86_exception *exception) { if (mmu != &vcpu->arch.nested_mmu) |