[PATCH 3/4] KVM: x86: pending exception must be be injected even with an injected event

[Maxim Levitsky]

Injected events should not block a pending exception, but rather,
should either be lost or be delivered to the nested hypervisor as part of
exitintinfo/IDT_VECTORING_INFO
(if nested hypervisor intercepts the pending exception)

Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
---
 arch/x86/kvm/svm/nested.c | 7 ++++++-
 arch/x86/kvm/vmx/nested.c | 9 +++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 881e3954d753b..4c82abce0ea0c 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1024,7 +1024,12 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
        }
 
        if (vcpu->arch.exception.pending) {
-               if (block_nested_events)
+               /*
+                * Only pending nested run can block an pending exception
+                * Otherwise an injected NMI/interrupt should either be
+                * lost or delivered to the nested hypervisor in EXITINTINFO
+                * */
+               if (svm->nested.nested_run_pending)
                         return -EBUSY;
                if (!nested_exit_on_exception(svm))
                        return 0;
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index b34e284bfa62a..20ed1a351b2d9 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3810,9 +3810,14 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu)
 
        /*
         * Process any exceptions that are not debug traps before MTF.
+        *
+        * Note that only pending nested run can block an pending exception
+        * Otherwise an injected NMI/interrupt should either be
+        * lost or delivered to the nested hypervisor in EXITINTINFO
         */
+
        if (vcpu->arch.exception.pending && !vmx_pending_dbg_trap(vcpu)) {
-               if (block_nested_events)
+               if (vmx->nested.nested_run_pending)
                        return -EBUSY;
                if (!nested_vmx_check_exception(vcpu, &exit_qual))
                        goto no_vmexit;
@@ -3829,7 +3834,7 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu)
        }
 
        if (vcpu->arch.exception.pending) {
-               if (block_nested_events)
+               if (vmx->nested.nested_run_pending)
                        return -EBUSY;
                if (!nested_vmx_check_exception(vcpu, &exit_qual))
                        goto no_vmexit;
-- 
2.26.2