[PATCH v1 2/4] KVM: arm64: Reject the GICv5 CPU interface hypercalls under pKVM

[Fuad Tabba <fuad.tabba@linux.dev>]

__vgic_v5_save_apr() and __vgic_v5_restore_vmcr_apr() remain callable
after pKVM finalises. pKVM never registers a GICv5 vgic, so neither has
a valid caller in protected mode, and on a GICv3 machine the registers
they access are UNDEFINED at EL2 and panic the hypervisor.

Reject both when protected mode is enabled.

Fixes: af325e87af5da ("KVM: arm64: gic-v5: Add vgic-v5 save/restore hyp interface")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 arch/arm64/kvm/hyp/nvhe/hyp-main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index d3df96ed8ba42..a9afd350b1fb3 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -695,6 +695,9 @@ static void handle___vgic_v5_save_apr(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(struct vgic_v5_cpu_if *, cpu_if, host_ctxt, 1);
 
+	if (unlikely(is_protected_kvm_enabled()))
+		return;
+
 	__vgic_v5_save_apr(kern_hyp_va(cpu_if));
 }
 
@@ -702,6 +705,9 @@ static void handle___vgic_v5_restore_vmcr_apr(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(struct vgic_v5_cpu_if *, cpu_if, host_ctxt, 1);
 
+	if (unlikely(is_protected_kvm_enabled()))
+		return;
+
 	__vgic_v5_restore_vmcr_apr(kern_hyp_va(cpu_if));
 }
 
-- 
2.39.5