diff options
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9bbcdbfc7f2c..67ebc1959724 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5876,11 +5876,35 @@ static int handle_nmi_window(struct kvm_vcpu *vcpu) return 1; } -static bool vmx_emulation_required_with_pending_exception(struct kvm_vcpu *vcpu) +/* + * Returns true if emulation is required (due to the vCPU having invalid state + * with unsrestricted guest mode disabled) and KVM can't faithfully emulate the + * current vCPU state. + */ +static bool vmx_unhandleable_emulation_required(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); - return vmx->emulation_required && !vmx->rmode.vm86_active && + if (!vmx->emulation_required) + return false; + + /* + * It is architecturally impossible for emulation to be required when a + * nested VM-Enter is pending completion, as VM-Enter will VM-Fail if + * guest state is invalid and unrestricted guest is disabled, i.e. KVM + * should synthesize VM-Fail instead emulation L2 code. This path is + * only reachable if userspace modifies L2 guest state after KVM has + * performed the nested VM-Enter consistency checks. + */ + if (vmx->nested.nested_run_pending) + return true; + + /* + * KVM only supports emulating exceptions if the vCPU is in Real Mode. + * If emulation is required, KVM can't perform a successful VM-Enter to + * inject the exception. + */ + return !vmx->rmode.vm86_active && (kvm_is_exception_pending(vcpu) || vcpu->arch.exception.injected); } @@ -5903,7 +5927,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) if (!kvm_emulate_instruction(vcpu, 0)) return 0; - if (vmx_emulation_required_with_pending_exception(vcpu)) { + if (vmx_unhandleable_emulation_required(vcpu)) { kvm_prepare_emulation_failure_exit(vcpu); return 0; } @@ -5927,7 +5951,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) int vmx_vcpu_pre_run(struct kvm_vcpu *vcpu) { - if (vmx_emulation_required_with_pending_exception(vcpu)) { + if (vmx_unhandleable_emulation_required(vcpu)) { kvm_prepare_emulation_failure_exit(vcpu); return 0; } |