Displaying 4 results from an estimated 4 matches for "vir_cpu_compare_superset".
2018 Dec 07
2
Usable and non-usable CPU models in nested virtualization
...rted from
virConnectGetDomainCapabilities as usable='yes' on a physical machine
while as usable='no' inside a VM running on the same machine. That's
not completely surprising.
But what surprises me is that those models are still reported from
virConnectCompareCPU as supported (VIR_CPU_COMPARE_SUPERSET) in the
nested environment and VMs can be started happily with them.
For instance, virConnectGetDomainCapabilities reports
<model usable='no'>Skylake-Client</model>
but when I try to use that model anyway, the VM starts fine with it:
<cpu mode='custom' match=&...
2018 Dec 11
2
Re: Usable and non-usable CPU models in nested virtualization
...e='yes' on a physical machine
>
>> while as usable='no' inside a VM running on the same machine. That's
>> not completely surprising.
>>
>> But what surprises me is that those models are still reported from
>> virConnectCompareCPU as supported (VIR_CPU_COMPARE_SUPERSET) in the
>
> virConnectCompareCPU uses CPUID data for comparison, which is not the
> same as a list of features QEMU/KVM can provide on the host. You should
> use virConnectCompareHypervisorCPU to check whether a given CPU can be
> used on the host.
>
>> nested environment an...
2018 Dec 11
0
Re: Usable and non-usable CPU models in nested virtualization
...mainCapabilities as usable='yes' on a physical machine
> while as usable='no' inside a VM running on the same machine. That's
> not completely surprising.
>
> But what surprises me is that those models are still reported from
> virConnectCompareCPU as supported (VIR_CPU_COMPARE_SUPERSET) in the
virConnectCompareCPU uses CPUID data for comparison, which is not the
same as a list of features QEMU/KVM can provide on the host. You should
use virConnectCompareHypervisorCPU to check whether a given CPU can be
used on the host.
> nested environment and VMs can be started happily wit...
2018 Dec 12
0
Re: Usable and non-usable CPU models in nested virtualization
...machine
> >
> >> while as usable='no' inside a VM running on the same machine. That's
> >> not completely surprising.
> >>
> >> But what surprises me is that those models are still reported from
> >> virConnectCompareCPU as supported (VIR_CPU_COMPARE_SUPERSET) in the
> >
> > virConnectCompareCPU uses CPUID data for comparison, which is not the
> > same as a list of features QEMU/KVM can provide on the host. You should
> > use virConnectCompareHypervisorCPU to check whether a given CPU can be
> > used on the host.
> >...