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authorPaul Mackerras <paulus@ozlabs.org>2018-10-08 14:24:30 +1100
committerPaul Mackerras <paulus@ozlabs.org>2018-10-09 16:14:54 +1100
commit901f8c3f6feb0225c14b3bc6237850fb921d2f2d (patch)
treed9f4edd5ed3899d8270b329990292ba5b52079d4
parentaa069a996951f3e2e38437ef0316685a5893fc7e (diff)
KVM: PPC: Book3S HV: Add NO_HASH flag to GET_SMMU_INFO ioctl result
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. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
-rw-r--r--Documentation/virtual/kvm/api.txt4
-rw-r--r--arch/powerpc/kvm/book3s_hv.c4
-rw-r--r--include/uapi/linux/kvm.h1
3 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index fde48b6708f1..df98b6304769 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 89bcf923d542..788bc61bd08c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4257,6 +4257,10 @@ 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 d9cec6b5cb37..7f2ff3a76995 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;