On Fri, Aug 25, 2017 at 07:53:39PM +1000, Paul Mackerras wrote:
> This adds information about storage keys to the struct returned by
> the KVM_PPC_GET_SMMU_INFO ioctl. The new fields replace a pad field,
> which was zeroed by previous kernel versions. Thus userspace that
> knows about the new fields will see zeroes when running on an older
> kernel, indicating that storage keys are not supported. The size of
> the structure has not changed.
>
> The number of keys is hard-coded for the CPUs supported by HV KVM,
> which is just POWER7, POWER8 and POWER9.
>
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---
> This is intended to go in after Ram Pai's patch fixing the H_ENTER
> code to not drop the top two bits of the key field.
>
> arch/powerpc/kvm/book3s_hv.c | 8 ++++++++
> include/uapi/linux/kvm.h | 3 ++-
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 359c79c..3d9b661 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -3325,6 +3325,14 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,
> if (radix_enabled())
> return -EINVAL;
>
> + /*
> + * POWER7, POWER8 and POWER9 all support 32 storage keys for data.
> + * POWER7 doesn't support keys for instruction accesses,
> + * POWER8 and POWER9 do.
> + */
> + info->data_keys = 32;
> + info->instr_keys = cpu_has_feature(CPU_FTR_ARCH_207S) ? 32 : 0;
> +
> info->flags = KVM_PPC_PAGE_SIZES_REAL;
> if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
> info->flags |= KVM_PPC_1T_SEGMENTS;
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 6cd63c1..8388875 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -711,7 +711,8 @@ struct kvm_ppc_one_seg_page_size {
> struct kvm_ppc_smmu_info {
> __u64 flags;
> __u32 slb_size;
> - __u32 pad;
> + __u16 data_keys; /* # storage keys supported for data */
> + __u16 instr_keys; /* # storage keys supported for instructions */
> struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
> };
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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