[RFC PATCH 26/28] arm64: rme: Allow checking SVE on VM instance

[Steven Price]

From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>

Given we have different types of VMs supported, check the
support for SVE for the given instance of the VM to accurately
report the status.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
 arch/arm64/include/asm/kvm_rme.h | 2 ++
 arch/arm64/kvm/arm.c             | 5 ++++-
 arch/arm64/kvm/rme.c             | 7 ++++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index 2254e28c855e..68e99e5107bc 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -40,6 +40,8 @@ struct rec {
 int kvm_init_rme(void);
 u32 kvm_realm_ipa_limit(void);
 
+bool kvm_rme_supports_sve(void);
+
 int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap);
 int kvm_init_realm_vm(struct kvm *kvm);
 void kvm_destroy_realm(struct kvm *kvm);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 645df5968e1e..1d0b8ac7314f 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -326,7 +326,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		r = get_kvm_ipa_limit();
 		break;
 	case KVM_CAP_ARM_SVE:
-		r = system_supports_sve();
+		if (kvm && kvm_is_realm(kvm))
+			r = kvm_rme_supports_sve();
+		else
+			r = system_supports_sve();
 		break;
 	case KVM_CAP_ARM_PTRAUTH_ADDRESS:
 	case KVM_CAP_ARM_PTRAUTH_GENERIC:
diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
index 543e8d10f532..6ae7871aa6ed 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -49,6 +49,11 @@ static bool rme_supports(unsigned long feature)
 	return !!u64_get_bits(rmm_feat_reg0, feature);
 }
 
+bool kvm_rme_supports_sve(void)
+{
+	return rme_supports(RMI_FEATURE_REGISTER_0_SVE_EN);
+}
+
 static int rmi_check_version(void)
 {
 	struct arm_smccc_res res;
@@ -1104,7 +1109,7 @@ static int config_realm_sve(struct realm *realm,
 	int max_sve_vq = u64_get_bits(rmm_feat_reg0,
 				      RMI_FEATURE_REGISTER_0_SVE_VL);
 
-	if (!rme_supports(RMI_FEATURE_REGISTER_0_SVE_EN))
+	if (!kvm_rme_supports_sve())
 		return -EINVAL;
 
 	if (cfg->sve_vq > max_sve_vq)
-- 
2.34.1