Messages in this thread | | | Subject | Re: [PATCH V2 1/5] ara virt interface of perf to support kvm guest os statistics collection in guest os | From | "Zhang, Yanmin" <> | Date | Tue, 22 Jun 2010 17:29:03 +0800 |
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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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