[PATCH v2 28/45] KVM: arm64: GICv3: Add GICv2 SGI handling to deactivation primitive

[Marc Zyngier]

The GICv2 SGIs require additional handling for deactivation, as they
are effectively multiple interrrupts muxed into one. Make sure we
check for the source CPU when deactivating.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/vgic/vgic-v3.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index f2e9b96c6b65c..1026031f22ff9 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -173,11 +173,20 @@ void vgic_v3_deactivate(struct kvm_vcpu *vcpu, u64 val)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_v3_cpu_if *cpuif = &vgic_cpu->vgic_v3;
+	u32 model = vcpu->kvm->arch.vgic.vgic_model;
 	struct kvm_vcpu *target_vcpu = NULL;
+	bool mmio = false, is_v2_sgi;
 	struct vgic_irq *irq;
 	unsigned long flags;
-	bool mmio = false;
 	u64 lr = 0;
+	u8 cpuid;
+
+	/* Snapshot CPUID, and remove it from the INTID */
+	cpuid = FIELD_GET(GENMASK_ULL(12, 10), val);
+	val &= ~GENMASK_ULL(12, 10);
+
+	is_v2_sgi = (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
+		     val < VGIC_NR_SGIS);
 
 	/*
 	 * We only deal with DIR when EOIMode==1, and only for SGI,
@@ -213,6 +222,9 @@ void vgic_v3_deactivate(struct kvm_vcpu *vcpu, u64 val)
 	 * - Or the irq is active, but not in an LR, and we can
 	 *   directly deactivate it by building a pseudo-LR, fold it,
 	 *   and queue a request to prune the resulting ap_list,
+	 *
+	 * Special care must be taken to match the source CPUID when
+	 * deactivating a GICv2 SGI.
 	 */
 	scoped_guard(raw_spinlock, &irq->irq_lock) {
 		target_vcpu = irq->vcpu;
@@ -230,6 +242,12 @@ void vgic_v3_deactivate(struct kvm_vcpu *vcpu, u64 val)
 			goto put;
 		}
 
+		/* GICv2 SGI: check that the cpuid matches */
+		if (is_v2_sgi && irq->active_source != cpuid) {
+			target_vcpu = NULL;
+			goto put;
+		}
+
 		/* (with a Dalek voice) DEACTIVATE!!!! */
 		lr = vgic_v3_compute_lr(vcpu, irq) & ~ICH_LR_ACTIVE_BIT;
 	}
-- 
2.47.3