Re: [PATCH v7 25/27] KVM: arm64: Add a capability to advertise SVE support

Andrew Jones
2019-04-04T20:39:31Z

On Fri, Mar 29, 2019 at 01:00:50PM +0000, Dave Martin wrote:
> To provide a uniform way to check for KVM SVE support amongst other
> features, this patch adds a suitable capability KVM_CAP_ARM_SVE,
> and reports it as present when SVE is available.
>
> Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> Reviewed-by: Julien Thierry <julien.thierry@arm.com>
> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
>
> ---
>
> Changes since v5:
>
> * [Julien Thierry] Strip out has_vhe() sanity-check, which wasn't in
> the most logical place, and anyway doesn't really belong in this
> patch.
>
> Moved to KVM: arm64/sve: Allow userspace to enable SVE for vcpus
> instead.
> ---
> arch/arm64/kvm/reset.c | 3 +++
> include/uapi/linux/kvm.h | 1 +
> 2 files changed, 4 insertions(+)
>
> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index 32c5ac0..f13378d 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -98,6 +98,9 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> case KVM_CAP_ARM_VM_IPA_SIZE:
> r = kvm_ipa_limit;
> break;
> + case KVM_CAP_ARM_SVE:
> + r = system_supports_sve();
> + break;
> default:
> r = 0;
> }
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index c3b8e7a..1d56444 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -988,6 +988,7 @@ struct kvm_ppc_resize_hpt {
> #define KVM_CAP_ARM_VM_IPA_SIZE 165
> #define KVM_CAP_MANUAL_DIRTY_LOG_PROTECT 166
> #define KVM_CAP_HYPERV_CPUID 167
> +#define KVM_CAP_ARM_SVE 168
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> --
> 2.1.4
>

Reviewed-by: Andrew Jones <drjones@redhat.com>