[libvirt] [RFC PATCH 0/2] nodeinfo: PPC64: Fix topology and siblings info on capabilities and nodeinfo

Andrea Bolognani abologna at redhat.com
Mon May 23 15:40:26 UTC 2016

On Thu, 2016-05-05 at 20:48 +0200, Andrea Bolognani wrote:
> On Fri, 2016-01-29 at 01:32 -0500, Shivaprasad G Bhat wrote:
> > The nodeinfo output was fixed earlier to reflect the actual cpus available in
> > KVM mode on PPC64. The earlier fixes covered the aspect of not making a host
> > look overcommitted when its not. The current fixes are aimed at helping the
> > users make better decisions on the kind of guest cpu topology that can be
> > supported on the given sucore_per_core setting of KVM host and also hint the
> > way to pin the guest vcpus efficiently.
> >  
> > I am planning to add some test cases once the approach is accepted.
> >  
> > With respect to Patch 2:
> > The second patch adds a new element to the cpus tag and I need your inputs on
> > if that is okay. Also if there is a
> >  better way. I am not sure if the existing
> > clients have RNG checks that might fail with the approach. Or if the checks
> > are not enoforced on the elements but only on the tags.
> >  
> > With my approach if the rng checks pass, the new element "capacity" even if
> > ignored by many clients would have no impact except for PPC64.
> >  
> > To the extent I looked at code, the siblings changes dont affect existing
> > libvirt functionality. Please do let me know otherwise.
> So, I've been going through this old thread trying to figure out
> a way to improve the status quo. I'd like to collect as much
> feedback as possible, especially from people who have worked in
> this area of libvirt before or have written tools based on it.

I forgot to link this OpenStack Nova spec[1] that
Shivaprasad pointed me to earlier.

[1] https://review.openstack.org/gitweb?p=openstack/nova-specs.git;a=commitdiff;h=4a0c9d1fdba1ec71916e5e1a8fed03502f1a0c
Andrea Bolognani
Software Engineer - Virtualization Team

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