[PATCH] KVM: x86: keep EOI exit bitmap accurate before loading it.

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

Guest may mask the IOAPIC entry before issue EOI. In such case,
EOI will not be intercepted by hypervisor, since the corrensponding
bit in eoi exit bitmap is not set after the masking of IOAPIC entry.

The solution here is to OR EOI_exit_bitmap with tmr.

Tested-by: Rongrong Liu <rongrongx.liu@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
---
 arch/x86/kvm/lapic.c |    9 +++++++++
 arch/x86/kvm/lapic.h |    2 ++
 arch/x86/kvm/x86.c   |    1 +
 virt/kvm/ioapic.c    |    6 +++---
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 93c2e93..759d24e 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -533,6 +533,15 @@ void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
 	}
 }
 
+void kvm_apic_update_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
+					u32 *tmr)
+{
+	u32 i;
+
+	for (i = 0; i < 8; i++)
+		*((u32 *)eoi_exit_bitmap + i) |= tmr[i];
+}
+
 static void apic_update_ppr(struct kvm_lapic *apic)
 {
 	u32 tpr, isrv, ppr, old_ppr;
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 6a11845..eda7be7 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -55,6 +55,8 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu);
 
 void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);
 void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
+void kvm_apic_update_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
+					u32 *tmr);
 int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);
 int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);
 int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d401684..4042bc0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5992,6 +5992,7 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
 
 	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
 	kvm_apic_update_tmr(vcpu, tmr);
+	kvm_apic_update_eoi_exitmap(vcpu, eoi_exit_bitmap, tmr);
 	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
 }
 
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index e8ce34c..ea5f697 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -254,9 +254,9 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
 	spin_lock(&ioapic->lock);
 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
 		e = &ioapic->redirtbl[index];
-		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
-		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
-		    index == RTC_GSI) {
+		if (!e->fields.mask && e->fields.trig_mode == IOAPIC_LEVEL_TRIG
+			|| kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
+				index) || index == RTC_GSI) {
 			if (kvm_apic_match_dest(vcpu, NULL, 0,
 				e->fields.dest_id, e->fields.dest_mode)) {
 				__set_bit(e->fields.vector,
-- 
1.7.1