[PATCH v10 28/43] arm64: RME: Allow checking SVE on VM instance

Steven Price
2025-08-20T14:59:31Z

From: Suzuki K Poulose <suzuki.poulose@arm.com>

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@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
---
arch/arm64/include/asm/kvm_rme.h | 2 ++
arch/arm64/kvm/arm.c | 5 ++++-
arch/arm64/kvm/rme.c | 5 +++++
3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index 7a4c82701e67..1490f57f3e14 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -90,6 +90,8 @@ void kvm_init_rme(void);
u32 kvm_realm_ipa_limit(void);
u32 kvm_realm_vgic_nr_lr(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 4a5d97b4e7d0..0fc76751c034 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -427,7 +427,10 @@ 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_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 71fb1e68f88d..4f52bb20c873 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -38,6 +38,11 @@ static bool rme_has_feature(unsigned long feature)
return !!u64_get_bits(rmm_feat_reg0, feature);
}

+bool kvm_rme_supports_sve(void)
+{
+ return rme_has_feature(RMI_FEATURE_REGISTER_0_SVE_EN);
+}
+
static int rmi_check_version(void)
{
struct arm_smccc_res res;
--
2.43.0