On Fri, 27 May 2016 13:16:49 +0200 Greg Kurz <gk...@linux.vnet.ibm.com> wrote:
> On Fri, 27 May 2016 13:58:28 +1000 > David Gibson <da...@gibson.dropbear.id.au> wrote: > > > On Thu, May 26, 2016 at 10:02:23AM +0200, Greg Kurz wrote: > > > As stated in linux/Documentation/virtual/kvm/api.txt: > > > > > > The maximum possible value for max_vcpu_id can be retrieved using the > > > KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time. > > > > > > If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that > > > max_vcpu_id is the same as the value returned from KVM_CAP_MAX_VCPUS. > > > > > > Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com> > > > > Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> > > > > Paolo, > > FYI Patch 1/3 was in David's pull request earlier today. It is now upstream. > > You may now apply 2/3 and 3/3. > > Thanks ! > Hi Paolo, Just a friendly reminder. Without this patch, we cannot create more than 128 single-threaded vCPUs on POWER8 if the host has unsplit cores. Thanks ! -- Greg > -- > Greg > > > > --- > > > kvm-all.c | 8 +++++++- > > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > > > diff --git a/kvm-all.c b/kvm-all.c > > > index e56f38527815..e74e0c6e2352 100644 > > > --- a/kvm-all.c > > > +++ b/kvm-all.c > > > @@ -1459,10 +1459,16 @@ static int kvm_max_vcpus(KVMState *s) > > > return (ret) ? ret : kvm_recommended_vcpus(s); > > > } > > > > > > +static int kvm_max_vcpu_id(KVMState *s) > > > +{ > > > + int ret = kvm_check_extension(s, KVM_CAP_MAX_VCPU_ID); > > > + return (ret) ? ret : kvm_max_vcpus(s); > > > +} > > > + > > > bool kvm_vcpu_id_is_valid(int vcpu_id) > > > { > > > KVMState *s = KVM_STATE(current_machine->accelerator); > > > - return vcpu_id >= 0 && vcpu_id < kvm_max_vcpus(s); > > > + return vcpu_id >= 0 && vcpu_id < kvm_max_vcpu_id(s); > > > } > > > > > > static int kvm_init(MachineState *ms) > > > > > > >