[PATCH v7 4/7] KVM: Add reset/restore rtc_status support

[Yang Zhang <yang.z.zhang@intel.com>]

From: Yang Zhang <yang.z.zhang@Intel.com>

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
---
 arch/x86/kvm/lapic.c |    9 +++++++++
 arch/x86/kvm/lapic.h |    2 ++
 virt/kvm/ioapic.c    |   43 +++++++++++++++++++++++++++++++++++++++++++
 virt/kvm/ioapic.h    |    1 +
 4 files changed, 55 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 96ab160..9c041fa 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -94,6 +94,14 @@ static inline int apic_test_vector(int vec, void *bitmap)
 	return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
 }
 
+bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+
+	return apic_test_vector(vector, apic->regs + APIC_ISR) ||
+		apic_test_vector(vector, apic->regs + APIC_IRR);
+}
+
 static inline void apic_set_vector(int vec, void *bitmap)
 {
 	set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
@@ -1665,6 +1673,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
 	apic->highest_isr_cache = -1;
 	kvm_x86_ops->hwapic_isr_update(vcpu->kvm, apic_find_highest_isr(apic));
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
+	kvm_rtc_irq_restore(vcpu);
 }
 
 void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 967519c..004d2ad 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -170,4 +170,6 @@ static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu)
 	return vcpu->arch.apic->pending_events;
 }
 
+bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector);
+
 #endif
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 8664812..0b12b17 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -90,6 +90,47 @@ static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
 	return result;
 }
 
+static void rtc_irq_reset(struct kvm_ioapic *ioapic)
+{
+	ioapic->rtc_status.pending_eoi = 0;
+	bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
+}
+
+static void rtc_irq_restore(struct kvm_ioapic *ioapic)
+{
+	struct kvm_vcpu *vcpu;
+	int vector, i, pending_eoi = 0;
+
+	if (RTC_GSI >= IOAPIC_NUM_PINS)
+		return;
+
+	vector = ioapic->redirtbl[RTC_GSI].fields.vector;
+	kvm_for_each_vcpu(i, vcpu, ioapic->kvm) {
+		if (kvm_apic_pending_eoi(vcpu, vector)) {
+			pending_eoi++;
+			__set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
+		}
+	}
+	ioapic->rtc_status.pending_eoi = pending_eoi;
+}
+
+void kvm_rtc_irq_restore(struct kvm_vcpu *vcpu)
+{
+	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
+	int vector;
+
+	if (!ioapic)
+		return;
+
+	spin_lock(&ioapic->lock);
+	vector = ioapic->redirtbl[RTC_GSI].fields.vector;
+	if (kvm_apic_pending_eoi(vcpu, vector)) {
+		__set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
+		ioapic->rtc_status.pending_eoi++;
+	}
+	spin_unlock(&ioapic->lock);
+}
+
 static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
 {
 	union kvm_ioapic_redirect_entry *pent;
@@ -431,6 +472,7 @@ void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 	ioapic->ioregsel = 0;
 	ioapic->irr = 0;
 	ioapic->id = 0;
+	rtc_irq_reset(ioapic);
 	update_handled_vectors(ioapic);
 }
 
@@ -496,6 +538,7 @@ int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 	spin_lock(&ioapic->lock);
 	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 	update_handled_vectors(ioapic);
+	rtc_irq_restore(ioapic);
 	kvm_ioapic_make_eoibitmap_request(kvm);
 	spin_unlock(&ioapic->lock);
 	return 0;
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 761e5b5..2692873 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -79,6 +79,7 @@ static inline struct kvm_ioapic *ioapic_irqchip(struct kvm *kvm)
 	return kvm->arch.vioapic;
 }
 
+void kvm_rtc_irq_restore(struct kvm_vcpu *vcpu);
 int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
 		int short_hand, int dest, int dest_mode);
 int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2);
-- 
1.7.1