KVM: x86: reset RVI upon system reset

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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 15 insertions, 8 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 5f574b4add90..e7f7fc632a9b 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1714,6 +1714,9 @@ 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 d6e3ddace074..f9d56c1945de 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7419,6 +7419,9 @@ static void vmx_set_rvi(int vector)
         u16 status;
         u8 old;
 
+        if (vector == -1)
+                vector = 0;
+
         status = vmcs_read16(GUEST_INTR_STATUS);
         old = (u8)status & 0xff;
         if ((u8)vector != old) {
@@ -7430,22 +7433,23 @@ static void vmx_set_rvi(int vector)
 
 static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
 {
+        if (!is_guest_mode(vcpu)) {
+                vmx_set_rvi(max_irr);
+                return;
+        }
+
         if (max_irr == -1)
                 return;
 
         /*
-         * If a vmexit is needed, vmx_check_nested_events handles it.
+         * In guest mode.  If a vmexit is needed, vmx_check_nested_events
+         * handles it.
          */
-        if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))
+        if (nested_exit_on_intr(vcpu))
                 return;
 
-        if (!is_guest_mode(vcpu)) {
-                vmx_set_rvi(max_irr);
-                return;
-        }
-
         /*
-         * Fall back to pre-APICv interrupt injection since L2
+         * Else, fall back to pre-APICv interrupt injection since L2
          * is run without virtual interrupt delivery.
          */
         if (!kvm_event_needs_reinjection(vcpu) &&