[libvirt] [PATCH 1/1] cpu_map.xml: add cmt/mbm feature to x86

[Jiri Denemark]

On Fri, Jun 17, 2016 at 09:25:14 +0200, Jiri Denemark wrote:
> On Fri, Jun 17, 2016 at 09:23:56 +0800, Qiaowei Ren wrote:
> > Some Intel processor families (e.g. the Intel Xeon processor E5 v3
> > family) introduced some PQos (Platform Qos) features, including CMT
> > (Cache Monitoring echnology) and MBM (Memory Bandwidth Monitoring),
> > to monitor or control shared resource. This patch add them into x86
> > part of cpu_map.xml to be used for applications (like OpenStack)
> > based on libvirt to get cpu capabilities.
> > 
> > Signed-off-by: Qiaowei Ren <qiaowei.ren at intel.com>
> > ---
> >  src/cpu/cpu_map.xml | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/src/cpu/cpu_map.xml b/src/cpu/cpu_map.xml
> > index 08aded2..2e2cb4f 100644
> > --- a/src/cpu/cpu_map.xml
> > +++ b/src/cpu/cpu_map.xml
> > @@ -320,6 +320,9 @@
> >      <feature name='rtm'>
> >        <cpuid function='0x00000007' ebx='0x00000800'/>
> >      </feature>
> > +    <feature name='cmt'>
> > +      <cpuid function='0x00000007' ebx='0x00001000'/>
> > +    </feature>
> >      <feature name='mpx'>
> >        <cpuid function='0x00000007' ebx='0x00004000'/>
> >      </feature>
> 
> This hunk won't apply since about a week ago. Please, use current git
> when sending patches.
> 
> > @@ -353,6 +356,14 @@
> >        <cpuid function='0x80000007' edx='0x00000100'/>
> >      </feature>
> >  
> > +    <!-- cpuid level 0x0000000f:1 (edx) -->
> > +    <feature name='mbm_total'> <!-- LLC Total MBM monitoring -->
> > +      <cpuid function='0x0000000f' edx='0x00000002'/>
> > +    </feature>
> > +    <feature name='mbm_local'> <!-- LLC Local MBM monitoring -->
> > +      <cpuid function='0x0000000f' edx='0x00000004'/>
> > +    </feature>
> > +
> 
> And keep the list of features sorted by CPUID level, i.e., these
> features should go after 0x0d and before 0x80000000.

Oh and I completely forgot the most important thing: it makes little
sense to add CPUID features that QEMU does not support. It will only
allow users to see the features in host CPU capabilities. So if the
purpose of these patches is to be able to advertise whether the
appropriate perf events are supported on current host, CPU features are
not the right way of doing that. I think domain capabilities XML would
be the right place to advertise what events are supported.

Jirka