Subject: [PATCH v4 02/49] irqchip/gic: Expose CPU interface VA to KVM

From: Marc Zyngier <[email-masked]>
Date: Thu, 20 Nov 2025 17:24:52 +0000

Future changes will require KVM to be able to perform deactivations
by writing to the physical CPU interface. Add the corresponding
VA to the kvm_info structure, and let KVM stash it.

Tested-by: Fuad Tabba <[email-masked]>
Signed-off-by: Marc Zyngier <[email-masked]>
---
 arch/arm64/kvm/vgic/vgic-v2.c         | 1 +
 drivers/irqchip/irq-gic.c             | 3 +++
 include/kvm/arm_vgic.h                | 3 +++
 include/linux/irqchip/arm-vgic-info.h | 2 ++
 4 files changed, 9 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index 381673f03c395..441efef80d609 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -385,6 +385,7 @@ int vgic_v2_probe(const struct gic_kvm_info *info)
 
 	kvm_vgic_global_state.can_emulate_gicv2 = true;
 	kvm_vgic_global_state.vcpu_base = info->vcpu.start;
+	kvm_vgic_global_state.gicc_base = info->gicc_base;
 	kvm_vgic_global_state.type = VGIC_V2;
 	kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;
 
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 1269ab8eb726a..ec70c84e9f91d 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1459,6 +1459,8 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
 	if (ret)
 		return;
 
+	gic_v2_kvm_info.gicc_base = gic_data[0].cpu_base.common_base;
+
 	if (static_branch_likely(&supports_deactivate_key))
 		vgic_set_kvm_info(&gic_v2_kvm_info);
 }
@@ -1620,6 +1622,7 @@ static void __init gic_acpi_setup_kvm_info(void)
 		return;
 
 	gic_v2_kvm_info.maint_irq = irq;
+	gic_v2_kvm_info.gicc_base = gic_data[0].cpu_base.common_base;
 
 	vgic_set_kvm_info(&gic_v2_kvm_info);
 }
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 7a0b972eb1b12..577723f5599bd 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -59,6 +59,9 @@ struct vgic_global {
 	/* virtual control interface mapping, HYP VA */
 	void __iomem		*vctrl_hyp;
 
+	/* Physical CPU interface, kernel VA */
+	void __iomem		*gicc_base;
+
 	/* Number of implemented list registers */
 	int			nr_lr;
 
diff --git a/include/linux/irqchip/arm-vgic-info.h b/include/linux/irqchip/arm-vgic-info.h
index a470a73a805aa..67d9d960273b9 100644
--- a/include/linux/irqchip/arm-vgic-info.h
+++ b/include/linux/irqchip/arm-vgic-info.h
@@ -24,6 +24,8 @@ struct gic_kvm_info {
 	enum gic_type	type;
 	/* Virtual CPU interface */
 	struct resource vcpu;
+	/* GICv2 GICC VA */
+	void __iomem	*gicc_base;
 	/* Interrupt number */
 	unsigned int	maint_irq;
 	/* No interrupt mask, no need to use the above field */
-- 
2.47.3