[PATCH 5/8] KVM: arm64: Prevent NV feature flag on systems w/o nested virt

[Oliver Upton <oliver.upton@linux.dev>]

It would appear that userspace can select the NV feature flag regardless
of whether the system actually supports the feature. Obviously a nested
guest isn't getting far in this situation; let's reject the flag
instead.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/arm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e40f3bfcb0a1..ef92c2f2de70 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1208,6 +1208,9 @@ static unsigned long system_supported_vcpu_features(void)
 		clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features);
 	}
 
+	if (!cpus_have_const_cap(ARM64_HAS_NESTED_VIRT))
+		clear_bit(KVM_ARM_VCPU_HAS_EL2, &features);
+
 	return features;
 }
 
-- 
2.42.0.515.g380fc7ccd1-goog