KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes

[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / kvm / powerpc.c

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index ccaa7a407c15c42d8dffe7c32ad4603079647062..b14736f3870beff7515fead4729ef2084657bafe 100644 (file)
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -566,6 +566,16 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
                                r = threads_per_subcore;
                }
                break;
+       case KVM_CAP_PPC_SMT_POSSIBLE:
+               r = 1;
+               if (hv_enabled) {
+                       if (!cpu_has_feature(CPU_FTR_ARCH_300))
+                               r = ((threads_per_subcore << 1) - 1);
+                       else
+                               /* P9 can emulate dbells, so allow any mode */
+                               r = 8 | 4 | 2 | 1;
+               }
+               break;
        case KVM_CAP_PPC_RMA:
                r = 0;
                break;