[PATCH v2] arm/arm64: KVM: vgic: kick the specific vcpu instead of iterating through all

[Shannon Zhao <zhaoshenglong@xxxxxxxxxx>]

When call kvm_vgic_inject_irq to inject irq, we can known which vcpu
the IRQ for by the irq_num and the cpuid. So we should just kick
this vcpu to avoid iterating through all.

Signed-off-by: Shannon Zhao <zhaoshenglong@xxxxxxxxxx>
---
 virt/kvm/arm/vgic.c |   32 ++++++++++++++++++++++++--------
 1 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 82db9d6..9dad67a 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -95,6 +95,7 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu);
 static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu);
 static void vgic_update_state(struct kvm *kvm);
 static void vgic_kick_vcpus(struct kvm *kvm);
+static void vgic_kick_vcpu(struct kvm *kvm, int cpuid);
 static u8 *vgic_get_sgi_sources(struct vgic_dist *dist, int vcpu_id, int sgi);
 static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
 static struct vgic_lr vgic_get_lr(const struct kvm_vcpu *vcpu, int lr);
@@ -1589,6 +1590,21 @@ static void vgic_kick_vcpus(struct kvm *kvm)
 	}
 }
 
+static void vgic_kick_vcpu(struct kvm *kvm, int cpuid)
+{
+	struct kvm_vcpu *vcpu;
+
+	/*
+	 * We've injected an interrupt, kick the specified vcpu
+	 */
+	if (cpuid < atomic_read(&kvm->online_vcpus)) {
+		vcpu = kvm_get_vcpu(kvm, cpuid);
+		if (vcpu != NULL) {
+			kvm_vcpu_kick(vcpu);
+		}
+	}
+}
+
 static int vgic_validate_injection(struct kvm_vcpu *vcpu, int irq, int level)
 {
 	int edge_triggered = vgic_irq_is_edge(vcpu, irq);
@@ -1607,7 +1623,7 @@ static int vgic_validate_injection(struct kvm_vcpu *vcpu, int irq, int level)
 	}
 }
 
-static bool vgic_update_irq_pending(struct kvm *kvm, int cpuid,
+static bool vgic_update_irq_pending(struct kvm *kvm, int *cpuid,
 				  unsigned int irq_num, bool level)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
@@ -1618,7 +1634,7 @@ static bool vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 
 	spin_lock(&dist->lock);
 
-	vcpu = kvm_get_vcpu(kvm, cpuid);
+	vcpu = kvm_get_vcpu(kvm, *cpuid);
 	edge_triggered = vgic_irq_is_edge(vcpu, irq_num);
 	level_triggered = !edge_triggered;
 
@@ -1628,11 +1644,11 @@ static bool vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 	}
 
 	if (irq_num >= VGIC_NR_PRIVATE_IRQS) {
-		cpuid = dist->irq_spi_cpu[irq_num - VGIC_NR_PRIVATE_IRQS];
-		vcpu = kvm_get_vcpu(kvm, cpuid);
+		*cpuid = dist->irq_spi_cpu[irq_num - VGIC_NR_PRIVATE_IRQS];
+		vcpu = kvm_get_vcpu(kvm, *cpuid);
 	}
 
-	kvm_debug("Inject IRQ%d level %d CPU%d\n", irq_num, level, cpuid);
+	kvm_debug("Inject IRQ%d level %d CPU%d\n", irq_num, level, *cpuid);
 
 	if (level) {
 		if (level_triggered)
@@ -1666,7 +1682,7 @@ static bool vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 
 	if (level) {
 		vgic_cpu_irq_set(vcpu, irq_num);
-		set_bit(cpuid, dist->irq_pending_on_cpu);
+		set_bit(*cpuid, dist->irq_pending_on_cpu);
 	}
 
 out:
@@ -1693,8 +1709,8 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
 			bool level)
 {
 	if (likely(vgic_initialized(kvm)) &&
-	    vgic_update_irq_pending(kvm, cpuid, irq_num, level))
-		vgic_kick_vcpus(kvm);
+	    vgic_update_irq_pending(kvm, &cpuid, irq_num, level))
+		vgic_kick_vcpu(kvm, cpuid);
 
 	return 0;
 }
-- 
1.7.1


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