Subject: [PATCH v2 08/18] KVM: arm64: vgic: Rationalise per-CPU irq accessor

From: Marc Zyngier <[email-masked]>
Date: Wed, 20 May 2026 10:19:39 +0100

Despite adding the necessary infrastructure to identify irq types,
vgic_get_vcpu_irq() treats GICv5 PPIs in a special way, which
impairs the readability of the code.

Use the existing irq classifiers to handle per-CPU irqs for all
vgic types, and let the normal control flow reach global interrupt
handling without any v5-specific path.

Reviewed-by: Joey Gouly <[email-masked]>
Signed-off-by: Marc Zyngier <[email-masked]>
---
 arch/arm64/kvm/vgic/vgic.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 3ac6d49bc4876..b697678d68b01 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -106,24 +106,23 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, u32 intid)
 
 struct vgic_irq *vgic_get_vcpu_irq(struct kvm_vcpu *vcpu, u32 intid)
 {
+	enum kvm_device_type type;
+
 	if (WARN_ON(!vcpu))
 		return NULL;
 
-	if (vgic_is_v5(vcpu->kvm)) {
-		u32 int_num, hwirq_id;
-
-		if (!__irq_is_ppi(KVM_DEV_TYPE_ARM_VGIC_V5, intid))
-			return NULL;
-
-		hwirq_id = FIELD_GET(GICV5_HWIRQ_ID, intid);
-		int_num = array_index_nospec(hwirq_id, VGIC_V5_NR_PRIVATE_IRQS);
+	type = vcpu->kvm->arch.vgic.vgic_model;
 
-		return &vcpu->arch.vgic_cpu.private_irqs[int_num];
-	}
+	if (__irq_is_sgi(type, intid) || __irq_is_ppi(type, intid)) {
+		switch (type) {
+		case KVM_DEV_TYPE_ARM_VGIC_V5:
+			intid = vgic_v5_get_hwirq_id(intid);
+			intid = array_index_nospec(intid, VGIC_V5_NR_PRIVATE_IRQS);
+			break;
+		default:
+			intid = array_index_nospec(intid, VGIC_NR_PRIVATE_IRQS);
+		}
 
-	/* SGIs and PPIs */
-	if (intid < VGIC_NR_PRIVATE_IRQS) {
-		intid = array_index_nospec(intid, VGIC_NR_PRIVATE_IRQS);
 		return &vcpu->arch.vgic_cpu.private_irqs[intid];
 	}
 
-- 
2.47.3