@@ -4255,14 +4255,6 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
nested_vmx_abort(vcpu,
VMX_ABORT_SAVE_GUEST_MSR_FAIL);
}
-
- /*
- * Drop what we picked up for L2 via vmx_complete_interrupts. It is
- * preserved above and would only end up incorrectly in L1.
- */
- vcpu->arch.nmi_injected = false;
- kvm_clear_exception_queue(vcpu);
- kvm_clear_interrupt_queue(vcpu);
}
/*
@@ -4602,6 +4594,17 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
WARN_ON_ONCE(nested_early_check);
}
+ /*
+ * Drop events/exceptions that were queued for re-injection to L2
+ * (picked up via vmx_complete_interrupts()), as well as exceptions
+ * that were pending for L2. Note, this must NOT be hoisted above
+ * prepare_vmcs12(), events/exceptions queued for re-injection need to
+ * be captured in vmcs12 (see vmcs12_save_pending_event()).
+ */
+ vcpu->arch.nmi_injected = false;
+ kvm_clear_exception_queue(vcpu);
+ kvm_clear_interrupt_queue(vcpu);
+
vmx_switch_vmcs(vcpu, &vmx->vmcs01);
/* Update any VMCS fields that might have changed while L2 ran */
Drop pending exceptions and events queued for re-injection when leaving nested guest mode, even if the "exit" is due to VM-Fail, SMI, or forced by host userspace. Failure to purge events could result in an event belonging to L2 being injected into L1. This _should_ never happen for VM-Fail as all events should be blocked by nested_run_pending, but it's possible if KVM, not the L1 hypervisor, is the source of VM-Fail when running vmcs02. SMI is a nop (barring unknown bugs) as recognition of SMI and thus entry to SMM is blocked by pending exceptions and re-injected events. Forced exit is definitely buggy, but has likely gone unnoticed because userspace probably follows the forced exit with KVM_SET_VCPU_EVENTS (or some other ioctl() that purges the queue). Fixes: 4f350c6dbcb9 ("kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> --- arch/x86/kvm/vmx/nested.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)