[PATCH 1/2] KVM: arm64: Disable KVM on systems with a VPIPT i-cache

[Marc Zyngier]

Systems with a VMID-tagged PIPT i-cache have been supported for
a while by Linux and KVM. However, these systems never appeared
on our side of the multiverse.

Refuse to initialise KVM on such a machine, should then ever appear.
Following changes will drop the support from the hypervisor.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/arm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9c5573bc4614..508deed213a2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2195,6 +2195,11 @@ int kvm_arch_init(void *opaque)
 	int err;
 	bool in_hyp_mode;
 
+	if (icache_is_vpipt()) {
+		kvm_info("Incompatible VPIPT I-Cache policy\n");
+		return -ENODEV;
+	}
+
 	if (!is_hyp_mode_available()) {
 		kvm_info("HYP mode not available\n");
 		return -ENODEV;
-- 
2.34.1