[PATCH 30/33] KVM: arm64: GICv2: Handle LR overflow when EOImode==0

[Marc Zyngier <maz@kernel.org>]

Similarly to the GICv3 version, handle the EOIcount-driven deactivation
by walking the overflow list.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-v2.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index 9d4702aec454b..0159da5a94412 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -100,6 +100,8 @@ static void vgic_v2_fold_lr(struct kvm_vcpu *vcpu, u32 val)
 	vgic_put_irq(vcpu->kvm, irq);
 }
 
+static u32 vgic_v2_compute_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq);
+
 /*
  * transfer the content of the LRs back into the corresponding ap_list:
  * - active bit is transferred as is
@@ -111,12 +113,37 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_v2_cpu_if *cpuif = &vgic_cpu->vgic_v2;
+	u32 eoicount = FIELD_GET(GICH_HCR_EOICOUNT, cpuif->vgic_hcr);
+	struct vgic_irq *irq;
 
 	DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
 
 	for (int lr = 0; lr < vgic_cpu->vgic_v2.used_lrs; lr++)
 		vgic_v2_fold_lr(vcpu, cpuif->vgic_lr[lr]);
 
+	/* See the GICv3 equivalent for the EOIcount handling rationale */
+	list_for_each_entry(irq, &vgic_cpu->overflow_ap_list_head, ap_list) {
+		u32 lr;
+
+		if (!eoicount) {
+			break;
+		} else {
+			guard(raw_spinlock)(&irq->irq_lock);
+
+			if (!(likely(vgic_target_oracle(irq) == vcpu) &&
+			      irq->active))
+				continue;
+
+			lr = vgic_v2_compute_lr(vcpu, irq) & ~GICH_LR_ACTIVE_BIT;
+		}
+
+		if (lr & GICH_LR_HW)
+			writel_relaxed(FIELD_GET(GICH_LR_PHYSID_CPUID, lr),
+				       kvm_vgic_global_state.gicc_base + GIC_CPU_DEACTIVATE);
+		vgic_v2_fold_lr(vcpu, lr);
+		eoicount--;
+	}
+
 	cpuif->used_lrs = 0;
 }
 
-- 
2.47.3