| Message ID | 1538976679-1363-34-git-send-email-paulus@ozlabs.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | KVM: PPC: Book3S HV: Nested HV virtualization | expand |
On Mon, Oct 08, 2018 at 04:31:19PM +1100, Paul Mackerras wrote: > This adds a KVM_PPC_NO_HASH flag to the flags field of the > kvm_ppc_smmu_info struct, and arranges for it to be set when > running as a nested hypervisor, as an unambiguous indication > to userspace that HPT guests are not supported. Reporting the > KVM_CAP_PPC_MMU_HASH_V3 capability as false could be taken as > indicating only that the new HPT features in ISA V3.0 are not > supported, leaving it ambiguous whether pre-V3.0 HPT features > are supported. > > Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > --- > Documentation/virtual/kvm/api.txt | 4 ++++ > arch/powerpc/kvm/book3s_hv.c | 4 ++++ > include/uapi/linux/kvm.h | 1 + > 3 files changed, 9 insertions(+) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index fde48b6..df98b63 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -2270,6 +2270,10 @@ The supported flags are: > The emulated MMU supports 1T segments in addition to the > standard 256M ones. > > + - KVM_PPC_NO_HASH > + This flag indicates that HPT guests are not supported by KVM, > + thus all guests must use radix MMU mode. > + > The "slb_size" field indicates how many SLB entries are supported > > The "sps" array contains 8 entries indicating the supported base > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index fa61647..f565403 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -4245,6 +4245,10 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm, > kvmppc_add_seg_page_size(&sps, 16, SLB_VSID_L | SLB_VSID_LP_01); > kvmppc_add_seg_page_size(&sps, 24, SLB_VSID_L); > > + /* If running as a nested hypervisor, we don't support HPT guests */ > + if (kvmhv_on_pseries()) > + info->flags |= KVM_PPC_NO_HASH; > + > return 0; > } > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index d9cec6b..7f2ff3a 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -719,6 +719,7 @@ struct kvm_ppc_one_seg_page_size { > > #define KVM_PPC_PAGE_SIZES_REAL 0x00000001 > #define KVM_PPC_1T_SEGMENTS 0x00000002 > +#define KVM_PPC_NO_HASH 0x00000004 > > struct kvm_ppc_smmu_info { > __u64 flags;
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index fde48b6..df98b63 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2270,6 +2270,10 @@ The supported flags are: The emulated MMU supports 1T segments in addition to the standard 256M ones. + - KVM_PPC_NO_HASH + This flag indicates that HPT guests are not supported by KVM, + thus all guests must use radix MMU mode. + The "slb_size" field indicates how many SLB entries are supported The "sps" array contains 8 entries indicating the supported base diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index fa61647..f565403 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4245,6 +4245,10 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm, kvmppc_add_seg_page_size(&sps, 16, SLB_VSID_L | SLB_VSID_LP_01); kvmppc_add_seg_page_size(&sps, 24, SLB_VSID_L); + /* If running as a nested hypervisor, we don't support HPT guests */ + if (kvmhv_on_pseries()) + info->flags |= KVM_PPC_NO_HASH; + return 0; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index d9cec6b..7f2ff3a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -719,6 +719,7 @@ struct kvm_ppc_one_seg_page_size { #define KVM_PPC_PAGE_SIZES_REAL 0x00000001 #define KVM_PPC_1T_SEGMENTS 0x00000002 +#define KVM_PPC_NO_HASH 0x00000004 struct kvm_ppc_smmu_info { __u64 flags;
This adds a KVM_PPC_NO_HASH flag to the flags field of the kvm_ppc_smmu_info struct, and arranges for it to be set when running as a nested hypervisor, as an unambiguous indication to userspace that HPT guests are not supported. Reporting the KVM_CAP_PPC_MMU_HASH_V3 capability as false could be taken as indicating only that the new HPT features in ISA V3.0 are not supported, leaving it ambiguous whether pre-V3.0 HPT features are supported. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> --- Documentation/virtual/kvm/api.txt | 4 ++++ arch/powerpc/kvm/book3s_hv.c | 4 ++++ include/uapi/linux/kvm.h | 1 + 3 files changed, 9 insertions(+)