diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 6 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 14 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 9 |
3 files changed, 18 insertions, 11 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1be4608669ea..0e63dcd8ac1c 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -267,7 +267,13 @@ enum x86_intercept_stage; #define PFERR_GUEST_ENC_MASK BIT_ULL(34) #define PFERR_GUEST_SIZEM_MASK BIT_ULL(35) #define PFERR_GUEST_VMPL_MASK BIT_ULL(36) + +/* + * IMPLICIT_ACCESS is a KVM-defined flag used to correctly perform SMAP checks + * when emulating instructions that triggers implicit access. + */ #define PFERR_IMPLICIT_ACCESS BIT_ULL(48) +#define PFERR_SYNTHETIC_MASK (PFERR_IMPLICIT_ACCESS) #define PFERR_NESTED_GUEST_PAGE (PFERR_GUEST_PAGE_MASK | \ PFERR_WRITE_MASK | \ diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 955de52e0c18..1b2ae00a7970 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4501,6 +4501,9 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, return -EFAULT; #endif + /* Ensure the above sanity check also covers KVM-defined flags. */ + BUILD_BUG_ON(lower_32_bits(PFERR_SYNTHETIC_MASK)); + vcpu->arch.l1tf_flush_l1d = true; if (!flags) { trace_kvm_page_fault(vcpu, fault_address, error_code); @@ -5785,17 +5788,6 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err int r, emulation_type = EMULTYPE_PF; bool direct = vcpu->arch.mmu->root_role.direct; - /* - * IMPLICIT_ACCESS is a KVM-defined flag used to correctly perform SMAP - * checks when emulating instructions that triggers implicit access. - * WARN if hardware generates a fault with an error code that collides - * with the KVM-defined value. Clear the flag and continue on, i.e. - * don't terminate the VM, as KVM can't possibly be relying on a flag - * that KVM doesn't know about. - */ - if (WARN_ON_ONCE(error_code & PFERR_IMPLICIT_ACCESS)) - error_code &= ~PFERR_IMPLICIT_ACCESS; - if (WARN_ON_ONCE(!VALID_PAGE(vcpu->arch.mmu->root.hpa))) return RET_PF_RETRY; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 0f3b59da0d4a..535018f152a3 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2047,6 +2047,15 @@ static int npf_interception(struct kvm_vcpu *vcpu) u64 fault_address = svm->vmcb->control.exit_info_2; u64 error_code = svm->vmcb->control.exit_info_1; + /* + * WARN if hardware generates a fault with an error code that collides + * with KVM-defined sythentic flags. Clear the flags and continue on, + * i.e. don't terminate the VM, as KVM can't possibly be relying on a + * flag that KVM doesn't know about. + */ + if (WARN_ON_ONCE(error_code & PFERR_SYNTHETIC_MASK)) + error_code &= ~PFERR_SYNTHETIC_MASK; + trace_kvm_page_fault(vcpu, fault_address, error_code); return kvm_mmu_page_fault(vcpu, fault_address, error_code, static_cpu_has(X86_FEATURE_DECODEASSISTS) ? |