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authorPaul Mackerras <paulus@ozlabs.org>2017-06-21 16:01:27 +1000
committerPaul Mackerras <paulus@ozlabs.org>2017-06-22 11:25:31 +1000
commit2ed4f9dd19c0f76f7fb56c4b201696d29149325c (patch)
treedc386c28edb9885280d62e1fb51fe2dd5b693a94 /arch/powerpc/kvm/powerpc.c
parente20bbd3d8d5c4432db8fd6f091b096963236064f (diff)
KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes
Now that userspace can set the virtual SMT mode by enabling the KVM_CAP_PPC_SMT capability, it is useful for userspace to be able to query the set of possible virtual SMT modes. This provides a new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this information. The return value is a bitmap of possible modes, with bit N set if virtual SMT mode 2^N is available. That is, 1 indicates SMT1 is available, 2 indicates that SMT2 is available, 3 indicates that both SMT1 and SMT2 are available, and so on. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc/kvm/powerpc.c')
-rw-r--r--arch/powerpc/kvm/powerpc.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index ccaa7a407c15..b14736f3870b 100644
--- 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;