[Devel] [PATCH rh7 v1] KVM: x86: set TMR when the interrupt is accepted

[Pavel Butsykin]

From: Paolo Bonzini <pbonzini at redhat.com>

Do not compute TMR in advance. Instead, set the TMR just before the interrupt
is accepted into the IRR. This limits the coupling between IOAPIC and LAPIC.

Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
---
 arch/x86/kvm/ioapic.c |  6 +-----
 arch/x86/kvm/ioapic.h |  3 +--
 arch/x86/kvm/lapic.c  | 19 ++++++++++---------
 arch/x86/kvm/lapic.h  |  1 -
 arch/x86/kvm/x86.c    |  5 +----
 5 files changed, 13 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index d442d94..dc2ae8d 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -246,8 +246,7 @@ static void update_handled_vectors(struct kvm_ioapic *ioapic)
 	smp_wmb();
 }
 
-void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
-			u32 *tmr)
+void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
 {
 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 	union kvm_ioapic_redirect_entry *e;
@@ -265,9 +264,6 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
 			     kvm_apic_pending_eoi(vcpu, e->fields.vector))) {
 				__set_bit(e->fields.vector,
 					(unsigned long *)eoi_exit_bitmap);
-				if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
-					__set_bit(e->fields.vector,
-						(unsigned long *)tmr);
 			}
 		}
 	}
diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index a5cdfc0..652d5c5 100644
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -114,7 +114,6 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
 		struct kvm_lapic_irq *irq, unsigned long *dest_map);
 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
-void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
-			u32 *tmr);
+void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
 
 #endif
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 07284ef..f42d8e4 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -552,15 +552,6 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu)
 	__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
 }
 
-void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
-{
-	struct kvm_lapic *apic = vcpu->arch.apic;
-	int i;
-
-	for (i = 0; i < 8; i++)
-		apic_set_reg(apic, APIC_TMR + 0x10 * i, tmr[i]);
-}
-
 static void apic_update_ppr(struct kvm_lapic *apic)
 {
 	u32 tpr, isrv, ppr, old_ppr;
@@ -765,6 +756,9 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 	case APIC_DM_LOWEST:
 		vcpu->arch.apic_arb_prio++;
 	case APIC_DM_FIXED:
+		if (unlikely(trig_mode && !level))
+			break;
+
 		/* FIXME add logic for vcpu on reset */
 		if (unlikely(!apic_enabled(apic)))
 			break;
@@ -774,6 +768,13 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 		if (dest_map)
 			__set_bit(vcpu->vcpu_id, dest_map);
 
+		if (apic_test_vector(vector, apic->regs + APIC_TMR) != !!trig_mode) {
+			if (trig_mode)
+				apic_set_vector(vector, apic->regs + APIC_TMR);
+			else
+				apic_clear_vector(vector, apic->regs + APIC_TMR);
+		}
+
 		if (kvm_x86_ops->deliver_posted_interrupt)
 			kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
 		else {
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index b5e88db..20013c9 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -57,7 +57,6 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value);
 u64 kvm_lapic_get_base(struct kvm_vcpu *vcpu);
 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);
 int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 dest);
 int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5a64850..7969de2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6228,18 +6228,15 @@ static void process_smi(struct kvm_vcpu *vcpu)
 static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
 {
 	u64 eoi_exit_bitmap[4];
-	u32 tmr[8];
 
 	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
 		return;
 
 	memset(eoi_exit_bitmap, 0, 32);
-	memset(tmr, 0, 32);
 
 	kvm_x86_ops->sync_pir_to_irr(vcpu);
-	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
+	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap);
 	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
-	kvm_apic_update_tmr(vcpu, tmr);
 }
 
 void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
-- 
1.9.1