[PATCH v22 09/23] KVM: arm64: Prevent unsupported vcpu features for VM types

[Suzuki K Poulose]

Prevent unsupported VCPU features for the protected VCPUs. Realms and pVMs
not support 32bit EL1 or NV yet. pKVM doesn't rely on the host vcpu
features and it clears the unsupported features while hyp_vcpu is
initialised. Block the features early in the vcpu init if we detect
incompatible features.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
 arch/arm64/kvm/arm.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index f31d31fa27ad9..9c2ef7ca6a961 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1668,11 +1668,12 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 	return -EINVAL;
 }
 
-static unsigned long system_supported_vcpu_features(void)
+static unsigned long system_supported_vcpu_features(struct kvm_vcpu *vcpu)
 {
 	unsigned long features = KVM_VCPU_VALID_FEATURES;
 
-	if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1))
+	if (vcpu_is_protected(vcpu) ||
+	    !cpus_have_final_cap(ARM64_HAS_32BIT_EL1))
 		clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features);
 
 	if (!kvm_supports_guest_pmuv3()) {
@@ -1688,7 +1689,8 @@ static unsigned long system_supported_vcpu_features(void)
 		clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features);
 	}
 
-	if (!cpus_have_final_cap(ARM64_HAS_NESTED_VIRT))
+	if (vcpu_is_protected(vcpu) ||
+	    !cpus_have_final_cap(ARM64_HAS_NESTED_VIRT))
 		clear_bit(KVM_ARM_VCPU_HAS_EL2, &features);
 
 	return features;
@@ -1708,7 +1710,7 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
 			return -ENOENT;
 	}
 
-	if (features & ~system_supported_vcpu_features())
+	if (features & ~system_supported_vcpu_features(vcpu))
 		return -EINVAL;
 
 	/*
-- 
2.43.0