[v2,5/5] KVM: nVMX: Fix conditions for NMI injection

Commit Message

Jan Kiszka March 16, 2013, 10:23 a.m. UTC

From: Jan Kiszka <[e-mail]>

The logic for checking if interrupts can be injected has to be applied
also on NMIs. The difference is that if NMI interception is on these
events are consumed and blocked by the VM exit.

Signed-off-by: Jan Kiszka <[e-mail]>
---
 arch/x86/kvm/vmx.c |   35 +++++++++++++++++++++++++++++++++++
 1 files changed, 35 insertions(+), 0 deletions(-)

Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 27e7e59..83a57b7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4189,6 +4189,12 @@  static bool nested_exit_on_intr(struct kvm_vcpu *vcpu)
 		PIN_BASED_EXT_INTR_MASK;
 }
 
+static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu)
+{
+	return get_vmcs12(vcpu)->pin_based_vm_exec_control &
+		PIN_BASED_NMI_EXITING;
+}
+
 static void enable_irq_window(struct kvm_vcpu *vcpu)
 {
 	u32 cpu_based_vm_exec_control;
@@ -4314,6 +4320,35 @@  static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
 
 static int vmx_nmi_allowed(struct kvm_vcpu *vcpu)
 {
+	if (is_guest_mode(vcpu)) {
+		struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+
+		if (to_vmx(vcpu)->nested.nested_run_pending ||
+		    vmcs_read32(GUEST_ACTIVITY_STATE) ==
+			   GUEST_ACTIVITY_WAIT_SIPI)
+			return 0;
+		if (nested_exit_on_nmi(vcpu)) {
+			/*
+			 * Check if the idt_vectoring_info_field is free. We
+			 * cannot raise EXIT_REASON_EXCEPTION_NMI if it isn't.
+			 */
+			if (vmcs12->idt_vectoring_info_field &
+			    VECTORING_INFO_VALID_MASK)
+				return 0;
+			nested_vmx_vmexit(vcpu);
+			vmcs12->vm_exit_reason = EXIT_REASON_EXCEPTION_NMI;
+			vmcs12->vm_exit_intr_info = NMI_VECTOR |
+				INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK;
+			/*
+			 * The NMI-triggered VM exit counts as injection:
+			 * clear this one and block further NMIs.
+			 */
+			vcpu->arch.nmi_pending = 0;
+			vmx_set_nmi_mask(vcpu, true);
+			return 0;
+		}
+	}
+
 	if (!cpu_has_virtual_nmis() && to_vmx(vcpu)->soft_vnmi_blocked)
 		return 0;