| Message ID | 20170825095339.GC14035@fergus.ozlabs.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@ozlabs.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > --- > 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]; > }; >
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@ozlabs.org> Patch applied to my kvm-ppc-next branch. Paul.
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]; };
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@ozlabs.org> --- 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(-)