[PATCH] KVM: arm64: vgic: Don't reset cpuif/redist addresses at finalize time

[PATCH] KVM: arm64: vgic: Don't reset cpuif/redist addresses at finalize time

[Marc Zyngier]

Although we are OK with rewriting idregs at finalize time, resetting
the guest's cpuif (GICv3) or redistributor (GICv3) addresses once
we start running the guest is a pretty bad idea.

Move back this initialisation to vgic creation time.

Fixes: a258a383b9177 ("KVM: arm64: gic-v5: Sanitize ID_AA64PFR2_EL1.GCIE")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 47169604100f2..fd872079f2a24 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -147,6 +147,15 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 
+	switch (type) {
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
+		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
+		break;
+	}
+	
 	/*
 	 * We've now created the GIC. Update the system register state
 	 * to accurately reflect what we've created.
@@ -684,10 +693,8 @@ void kvm_vgic_finalize_idregs(struct kvm *kvm)
 
 	switch (type) {
 	case KVM_DEV_TYPE_ARM_VGIC_V2:
-		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
 		break;
 	case KVM_DEV_TYPE_ARM_VGIC_V3:
-		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
 		aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
 		pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3);
 		break;
-- 
2.47.3

Re: [PATCH] KVM: arm64: vgic: Don't reset cpuif/redist addresses at finalize time

[Marc Zyngier]

On Mon, 23 Mar 2026 17:47:13 +0000, Marc Zyngier wrote:
> Although we are OK with rewriting idregs at finalize time, resetting
> the guest's cpuif (GICv3) or redistributor (GICv3) addresses once
> we start running the guest is a pretty bad idea.
> 
> Move back this initialisation to vgic creation time.
> 
> 
> [...]

Applied to next, thanks!

[1/1] KVM: arm64: vgic: Don't reset cpuif/redist addresses at finalize time
      commit: bb90920c5ae1217449409dc0b5256c6ed4ccab27

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.