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

Steven Price
2023-01-27T11:33:39Z

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>
---
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