[PATCH v4 15/49] KVM: arm64: GICv2: Preserve EOIcount on exit

Marc Zyngier
2025-11-20T17:25:59Z

EOIcount is how the virtual CPU interface signals that the guest
is deactivating interrupts outside of the LRs when EOImode==0.

We therefore need to preserve that information so that we can find
out what actually needs deactivating, just like we already do on
GICv3.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/vgic/vgic-v2.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index 74efacba38d42..5cfbe58983428 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -437,6 +437,12 @@ void vgic_v2_save_state(struct kvm_vcpu *vcpu)
return;

if (used_lrs) {
+ if (vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr & GICH_HCR_LRENPIE) {
+ u32 val = readl_relaxed(base + GICH_HCR);
+
+ vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr &= ~GICH_HCR_EOICOUNT;
+ vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr |= val & GICH_HCR_EOICOUNT;
+ }
save_lrs(vcpu, base);
writel_relaxed(0, base + GICH_HCR);
}
--
2.47.3