Re: 2.6.16-rc5 perfmon2 new code base + libpfm with Montecito support

[Stephane Eranian <eranian@hpl.hp.com>]

Will,

On Wed, Mar 08, 2006 at 03:40:16PM -0500, William Cohen wrote:
> >
> >I have released another version of the perfmon new base package.
> >This release is relative to 2.6.16-rc5
> 
> Hello Stephane,
> 
> Is there any thoughts on how perfmon2 is going to work with xen enabled 
> kernels or processors that support virtualization?
> 

AFAIK, there is currently no Xen support for PMU on any platforms. By "support"
I mean suport for guests using the PMU. As such, I do not think this works.
I am planning on looking at this next because this is becoming a pressing matter
and not just on IA-64.

My first goal is to ensure that a guest using perfmon2 works once it is virtualized.
That implies that the Xen VMM does save/restore PMU state on guest switch. That's a bare
minimum.

As for HW virutlization support, I think it helps a little bit but there still needs to
be some additional code in the VMM to make this work correctly. This is also something
I want to look at.

-- 
-Stephane