KVM: PPC: Introduce KVM_CAP_PPC_HTM

Introduce a new KVM capability, KVM_CAP_PPC_HTM, that can be queried to
determine if a PowerPC KVM guest should use HTM (Hardware Transactional
Memory).

This will be used by QEMU to populate the pa-features bits in the
guest's device tree.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 5 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 1ac036e45ed4..6ce40dd6fe51 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -588,6 +588,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
                 r = 1;
                 break;
 #endif
+        case KVM_CAP_PPC_HTM:
+                r = cpu_has_feature(CPU_FTR_TM_COMP) &&
+                    is_kvmppc_hv_enabled(kvm);
+                break;
         default:
                 r = 0;
                 break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 8f2756c263d4..e98bb4cce639 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -869,6 +869,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_X2APIC_API 129
 #define KVM_CAP_S390_USER_INSTR0 130
 #define KVM_CAP_MSI_DEVID 131
+#define KVM_CAP_PPC_HTM 132
 
 #ifdef KVM_CAP_IRQ_ROUTING