[openstack-dev] [nova] Gap between host cpu features and guest cpu's

Sylvain Bauza sbauza at redhat.com
Wed May 11 07:28:26 UTC 2016

Le 11/05/2016 05:12, Jin, Yuntong a écrit :
> Hi everyone,
> Currently nova exposes all the host CPU instruction set extensions 
> available
> on the compute node in the host state, and there is a scheduler filter
> `ComputeCapabilitiesFilter` which looks at these.
> But the limits on this is:
> CPU instruction set in ComputeCapabilitiesFilter should be guest's 
> view instead of host's.
> Admin may use specific set of CPU instruction to deploy instance to make
> it migratable in a heterogeneous cloud.
> This is actually by design in nova as nova is using baselineCPU
> andallowed to pass/config guest CPU instruction feature for instance.
> Shall we add a string “guest_features” in ``ComputeNode`` object as 
> ``ComputeNode:cpu_info:guest_features``
> And let ComputeCapabilitiesFilter use guest_features instead of host 
> features here?
> Is this a real gap ? and the above easy fix is the right way ?

FWIW, we had a discussion during the Design Summit on the scheduler Nova 
design session about host capabilities and what we call "qualitative 
resources" [1]

A first step for helping our users to discover the CPU capabilities is 
to provide a Nova abstraction between all our related hypervisor driver 
features and you can comment on a proposal [2]


[1] https://etherpad.openstack.org/p/newton-nova-scheduler

[2] https://review.openstack.org/#/c/309762/
> Thanks
> -yuntongjin
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20160511/4d5396c0/attachment.html>

More information about the OpenStack-dev mailing list