Am 12.02.2016 um 12:08 schrieb Denis V. Lunev: > On 02/12/2016 02:00 PM, Andreas Färber wrote: >> Am 11.02.2016 um 21:19 schrieb Denis V. Lunev: >>> From: "Alexey V. Kostyushko" <alek...@virtuozzo.com> >>> >>> With Hyper-V enabled CPU hotplug stops working. The CPU appears in >>> device >>> manager on Windows but does not appear in peformance monitor and control >>> panel. >>> >>> The root of the problem is the following. Windows checks >>> HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE bit in CPUID. The presence of >>> this bit is enough to cure the situation. >>> >>> Add option 'hv-cpuhotplug' to control this behavior. >>> >>> Signed-off-by: Alexey V. Kostyushko <alek...@virtuozzo.com> >>> Signed-off-by: Denis V. Lunev <d...@openvz.org> >>> CC: Paolo Bonzini <pbonz...@redhat.com> >>> CC: Richard Henderson <r...@twiddle.net> >>> CC: Eduardo Habkost <ehabk...@redhat.com> >>> CC: "Andreas Färber" <afaer...@suse.de> >>> --- >>> target-i386/cpu-qom.h | 1 + >>> target-i386/cpu.c | 1 + >>> target-i386/kvm.c | 6 +++++- >>> 3 files changed, 7 insertions(+), 1 deletion(-) >>> >>> diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h >>> index 5f9d960..4aec616 100644 >>> --- a/target-i386/cpu-qom.h >>> +++ b/target-i386/cpu-qom.h >>> @@ -96,6 +96,7 @@ typedef struct X86CPU { >>> bool hyperv_runtime; >>> bool hyperv_synic; >>> bool hyperv_stimer; >>> + bool hyperv_cpuhotplug; >>> bool check_cpuid; >>> bool enforce_cpuid; >>> bool expose_kvm; >>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c >>> index b255644..32c38ae 100644 >>> --- a/target-i386/cpu.c >>> +++ b/target-i386/cpu.c >>> @@ -3172,6 +3172,7 @@ static Property x86_cpu_properties[] = { >>> DEFINE_PROP_BOOL("hv-runtime", X86CPU, hyperv_runtime, false), >>> DEFINE_PROP_BOOL("hv-synic", X86CPU, hyperv_synic, false), >>> DEFINE_PROP_BOOL("hv-stimer", X86CPU, hyperv_stimer, false), >>> + DEFINE_PROP_BOOL("hv-cpuhotplug", X86CPU, hyperv_cpuhotplug, >>> false), >> Is "cpuhotplug" some fixed HyperV name? Otherwise we generally use a >> dashes convention for QOM properties, i.e. "hv-cpu-hotplug". >> >> Regards, >> Andreas > This name is for libvirt. We can take one one. This is not a problem. > > Roman Kagan has proposed verbally a bit different approach. > He suggests not to introduce the option but > check here that HyperV is enabled (any single option is enough > to face the problem) and CPU hotplug is enabled and automatically > enable this bit. > > Paolo, Andreas, is there any opinion on this?
That implicit proposal sounds even more appealing to me, yes. You could still additionally do a dynamic property though, in case you want to inspect or toggle it at runtime (no clue when Windows reads it). Andreas > As far as I can see for the time being we lend such decisions to > libvirt. But this bit does not require any processing. > > Den -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton; HRB 21284 (AG Nürnberg)