[PATCH v2 11/22] KVM: nSVM: Report NMIs as allowed when in L2 and Exit-on-NMI is set

From: Paolo Bonzini
Date: Sat Apr 25 2020 - 03:02:14 EST


Report NMIs as allowed when the vCPU is in L2 and L2 is being run with
Exit-on-NMI enabled, as NMIs are always unblocked from L1's perspective
in this case.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 5 -----
arch/x86/kvm/svm/svm.c | 3 +++
arch/x86/kvm/svm/svm.h | 5 +++++
3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index c3650efd2e89..748b01220aac 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -776,11 +776,6 @@ int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
return vmexit;
}

-static bool nested_exit_on_nmi(struct vcpu_svm *svm)
-{
- return (svm->nested.intercept & (1ULL << INTERCEPT_NMI));
-}
-
static void nested_svm_nmi(struct vcpu_svm *svm)
{
svm->vmcb->control.exit_code = SVM_EXIT_NMI;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 01ee1c3be25b..3f1f80737f9e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3068,6 +3068,9 @@ static bool svm_nmi_allowed(struct kvm_vcpu *vcpu)
struct vmcb *vmcb = svm->vmcb;
bool ret;

+ if (is_guest_mode(vcpu) && nested_exit_on_nmi(svm))
+ return true;
+
ret = !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
!(svm->vcpu.arch.hflags & HF_NMI_MASK);
ret = ret && gif_set(svm);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a2bc33aadb67..d8ae654340d4 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -378,6 +378,11 @@ static inline bool svm_nested_virtualize_tpr(struct kvm_vcpu *vcpu)
return is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK);
}

+static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
+{
+ return (svm->nested.intercept & (1ULL << INTERCEPT_NMI));
+}
+
void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
struct vmcb *nested_vmcb, struct kvm_host_map *map);
int nested_svm_vmrun(struct vcpu_svm *svm);
--
2.18.2