Re: [PATCH RFC 0/3] Add guest cpu_entitlement reporting

[Michael Wolf]

On Mon, 2012-08-27 at 13:31 -0700, Avi Kivity wrote:
> On 08/27/2012 01:23 PM, Michael Wolf wrote:
> > > 
> > > How would a guest know what its entitlement is?
> > > 
> > > 
> >
> > Currently the Admin/management tool setting up the guests will put it on
> > the qemu commandline.  From this it is passed via an ioctl to the host.
> > The guest will get the value from the host via a hypercall.
> >
> > In the future the host could try and do some of it automatically in some
> > cases. 
> 
> Seems to me it's a meaningless value for the guest.  Suppose it is
> migrated to a host that is more powerful, and as a result its relative
> entitlement is reduced.  The value needs to be adjusted.

This is why I chose to manage the value from the sysctl interface rather
than just have it stored as a value in /proc.  Whatever tool was used to
migrate the vm could hopefully adjust the sysctl value on the guest.
> 
> This is best taken care of from the host side.

Not sure what you are getting at here.  If you are running in a cloud
environment, you purchase a VM with the understanding that you are
getting certain resources.  As this type of user I don't believe you
have any access to the host to see this type of information.  So the
user still wouldnt have a way to confirm that they are receiving what
they should be in the way of processor resources.

Would you please elaborate a little more on this?
> 



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