[PATCH] KVM: x86: reset RVI upon system reset

[Wei Wang <wei.w.wang@intel.com>]

A bug was reported as follows: when running Windows 7 32-bit guests on qemu-kvm,
sometimes the guests run into blue screen during reboot. The problem was that a
guest's RVI was not cleared when it rebooted. This patch has fixed the problem.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Tested-by: Rongrong Liu <rongrongx.liu@intel.com>, Da Chun <ngugc@qq.com>
---
 arch/x86/kvm/lapic.c |    3 +++
 arch/x86/kvm/vmx.c   |   12 ++++++------
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 66dd173..6942742 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1712,6 +1712,9 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
 	apic->isr_count = kvm_apic_vid_enabled(vcpu->kvm) ?
 				1 : count_vectors(apic->regs + APIC_ISR);
 	apic->highest_isr_cache = -1;
+	if (kvm_x86_ops->hwapic_irr_update)
+		kvm_x86_ops->hwapic_irr_update(vcpu,
+				apic_find_highest_irr(apic));
 	kvm_x86_ops->hwapic_isr_update(vcpu->kvm, apic_find_highest_isr(apic));
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
 	kvm_rtc_eoi_tracking_restore_one(vcpu);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fe4d2f4..d632548 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7292,19 +7292,19 @@ static void vmx_set_rvi(int vector)
 static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
 {
 	if (max_irr == -1)
+		max_irr = 0;
+
+	if (!is_guest_mode(vcpu)) {
+		vmx_set_rvi(max_irr);
 		return;
+	}
 
 	/*
 	 * If a vmexit is needed, vmx_check_nested_events handles it.
 	 */
-	if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))
+	if ((is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) || max_irr == 0)
 		return;
 
-	if (!is_guest_mode(vcpu)) {
-		vmx_set_rvi(max_irr);
-		return;
-	}
-
 	/*
 	 * Fall back to pre-APICv interrupt injection since L2
 	 * is run without virtual interrupt delivery.
-- 
1.7.1