[Qemu-devel] host doesn't support requested feature: CPUID.01H:EDX.ds [bit 21] Does this warn affect virtual machine performance or use?

[Qemu-devel] host doesn't support requested feature: CPUID.01H:EDX.ds [bit 21] Does this warn affect virtual machine performance or use?

[Paul Schlacter]

this is my stackoverflow question:
https://stackoverflow.com/questions/46219552/host-doesnt-support-requested-feature-cpuid-01hedx-ds-bit-21-does-this-warn


I found a lot of warning from the VM qemu log, Does this warn affect
virtual machine performance or use? , is my libvirt.xml file problem? Or
support hot-plug will have these warnings

This is my libvirt xml configuration:

<domain type='kvm' id='315'>
  <name>instance-000005b2</name>
  <uuid>793fe065-36a6-4840-80cf-840ebed41d3e</uuid>
  <maxMemory slots='32' unit='KiB'>68719476736</maxMemory>
  <memory unit='KiB'>2097152</memory>
  <currentMemory unit='KiB'>2097152</currentMemory>
  <vcpu placement='auto'>8</vcpu>
  <vcpus>
    <vcpu id='0' enabled='yes' hotpluggable='no' order='1'/>
    <vcpu id='1' enabled='yes' hotpluggable='yes' order='2'/>
    <vcpu id='2' enabled='yes' hotpluggable='yes' order='3'/>
    <vcpu id='3' enabled='yes' hotpluggable='yes' order='4'/>
    <vcpu id='4' enabled='yes' hotpluggable='yes' order='5'/>
    <vcpu id='5' enabled='yes' hotpluggable='yes' order='6'/>
    <vcpu id='6' enabled='yes' hotpluggable='yes' order='7'/>
    <vcpu id='7' enabled='yes' hotpluggable='yes' order='8'/>
  </vcpus>
  <cputune>
    <shares>2048</shares>
    <vcpupin vcpu='0' cpuset='0-9,20-29'/>
    <vcpupin vcpu='1' cpuset='0-9,20-29'/>
    <emulatorpin cpuset='0-9,20-29'/>
  </cputune>
  <numatune>
    <memory mode='strict' nodeset='0'/>
    <memnode cellid='0' mode='strict' nodeset='0'/>
  </numatune>
  <resource>
    <partition>/machine</partition>
  </resource>
  <os>
    <type arch='x86_64' machine='pc-i440fx-rhel7.3.0'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
  </features>
  <cpu mode='host-model'>
    <model fallback='allow'/>
    <numa>
      <cell id='0' cpus='0-1' memory='2097152' unit='KiB'/>
    </numa>
  </cpu>
  <devices>
    <emulator>/usr/libexec/qemu-kvm</emulator>
    <controller type='virtio-serial' index='0'>
      <alias name='virtio-serial0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04'
function='0x0'/>
    </controller>
    <memballoon model='virtio'>
      <alias name='balloon0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
    </memballoon>
  </devices>
</domain>




The following warn log：


2017-09-14T12:16:03.441702Z qemu-kvm: warning: CPU(s) not present in
any NUMA nodes: 2 3 4 5 6 7
2017-09-14T12:16:03.441773Z qemu-kvm: warning: All CPU(s) up to
maxcpus should be described in NUMA config
warning: host doesn't support requested feature: CPUID.01H:EDX.ds [bit 21]
warning: host doesn't support requested feature: CPUID.01H:EDX.acpi [bit 22]
warning: host doesn't support requested feature: CPUID.01H:EDX.ht [bit 28]
warning: host doesn't support requested feature: CPUID.01H:EDX.tm [bit 29]
warning: host doesn't support requested feature: CPUID.01H:EDX.pbe [bit 31]
warning: host doesn't support requested feature: CPUID.01H:ECX.dtes64 [bit 2]
warning: host doesn't support requested feature: CPUID.01H:ECX.monitor [bit 3]
warning: host doesn't support requested feature: CPUID.01H:ECX.ds_cpl [bit 4]
warning: host doesn't support requested feature: CPUID.01H:ECX.vmx [bit 5]
warning: host doesn't support requested feature: CPUID.01H:ECX.smx [bit 6]
warning: host doesn't support requested feature: CPUID.01H:ECX.est [bit 7]
warning: host doesn't support requested feature: CPUID.01H:ECX.tm2 [bit 8]
warning: host doesn't support requested feature: CPUID.01H:ECX.xtpr [bit 14]
warning: host doesn't support requested feature: CPUID.01H:ECX.pdcm [bit 15]
warning: host doesn't support requested feature: CPUID.01H:ECX.dca [bit 18]
warning: host doesn't support requested feature: CPUID.01H:ECX.osxsave [bit 27]
warning: host doesn't support requested feature: CPUID.01H:EDX.ds [bit 21]
warning: host doesn't support requested feature: CPUID.01H:EDX.acpi [bit 22]
warning: host doesn't support requested feature: CPUID.01H:EDX.ht [bit 28]
warning: host doesn't support requested feature: CPUID.01H:EDX.tm [bit 29]
warning: host doesn't support requested feature: CPUID.01H:EDX.pbe [bit 31]
warning: host doesn't support requested feature: CPUID.01H:ECX.dtes64 [bit 2]
warning: host doesn't support requested feature: CPUID.01H:ECX.monitor [bit 3]
warning: host doesn't support requested feature: CPUID.01H:ECX.ds_cpl [bit 4]

Re: [Qemu-devel] host doesn't support requested feature: CPUID.01H:EDX.ds [bit 21] Does this warn affect virtual machine performance or use?

[Jiri Denemark]

On Thu, Sep 14, 2017 at 20:48:49 +0800, Paul Schlacter wrote:
> this is my stackoverflow question:
> https://stackoverflow.com/questions/46219552/host-doesnt-support-requested-feature-cpuid-01hedx-ds-bit-21-does-this-warn
> 
> 
> I found a lot of warning from the VM qemu log, Does this warn affect
> virtual machine performance or use? , is my libvirt.xml file problem? Or
> support hot-plug will have these warnings
> 
> This is my libvirt xml configuration:
> 
> <domain type='kvm' id='315'>
...
>   <cpu mode='host-model'>
>     <model fallback='allow'/>
>     <numa>
>       <cell id='0' cpus='0-1' memory='2097152' unit='KiB'/>
>     </numa>
>   </cpu>
...
> 2017-09-14T12:16:03.441702Z qemu-kvm: warning: CPU(s) not present in
> any NUMA nodes: 2 3 4 5 6 7
> 2017-09-14T12:16:03.441773Z qemu-kvm: warning: All CPU(s) up to
> maxcpus should be described in NUMA config
> warning: host doesn't support requested feature: CPUID.01H:EDX.ds [bit 21]
> warning: host doesn't support requested feature: CPUID.01H:EDX.acpi [bit 22]
> warning: host doesn't support requested feature: CPUID.01H:EDX.ht [bit 28]
> warning: host doesn't support requested feature: CPUID.01H:EDX.tm [bit 29]
...

Similar warnings are expected with host-model CPUs on older libvirt
which didn't know how to ask QEMU what CPU features are supported on the
host. Thus libvirt just used CPUID and asked for everything and QEMU
filtered a lot of them. You need a recent QEMU and libvirt to avoid
these warnings.

Jirka