Re: [PATCH V2 1/5] ara virt interface of perf to support kvm guestos statistics collection in guest os

[Zhang, Yanmin]

On Tue, 2010-06-22 at 10:00 +0200, Jes Sorensen wrote:
> On 06/22/10 09:55, Peter Zijlstra wrote:
> > On Tue, 2010-06-22 at 15:47 +0800, Zhang, Yanmin wrote:
> >> Besides the para virt perf interface, I'm also considering the direct exposition
> >> of PMU hardware to guest os. 
> > 
> > NAK NAK NAK NAK, we've been over that, its not going to happen, full
> > stop!
> > 
> > Use MSR read/write traps and host perf to emulate the hardware. In some
> > cases we could allow the reads without trap but that's a later
> > optimization.
> 
> I believe whats meant here is a PMU compatible interface which is
> partially emulated. Not a handover of the PMU.
Right. We need capture all write to PMU MSR and allows guest os to read MSR directly.

Yanmin

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