Subject: [PATCH v4 11/49] KVM: arm64: GICv3: Preserve EOIcount on exit

From: Marc Zyngier <[email-masked]>
Date: Thu, 20 Nov 2025 17:25:01 +0000

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.

Tested-by: Fuad Tabba <[email-masked]>
Signed-off-by: Marc Zyngier <[email-masked]>
---
 arch/arm64/kvm/hyp/vgic-v3-sr.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index e72d436dd6a36..9bfcbfd91118a 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -225,6 +225,12 @@ void __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if)
 
 		elrsr = read_gicreg(ICH_ELRSR_EL2);
 
+		if (cpu_if->vgic_hcr & ICH_HCR_EL2_LRENPIE) {
+			u64 val = read_gicreg(ICH_HCR_EL2);
+			cpu_if->vgic_hcr &= ~ICH_HCR_EL2_EOIcount;
+			cpu_if->vgic_hcr |= val & ICH_HCR_EL2_EOIcount;
+		}
+
 		write_gicreg(0, ICH_HCR_EL2);
 
 		for (i = 0; i < used_lrs; i++) {
-- 
2.47.3