Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH V5 1/2] perf ignore LBR and extra_regs | Date | Mon, 14 Jul 2014 13:44:32 +0000 |
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> -----Original Message----- > From: Paolo Bonzini [mailto:pbonzini@redhat.com] > Sent: Monday, July 14, 2014 9:40 AM > To: Liang, Kan; Peter Zijlstra > Cc: andi@firstfloor.org; linux-kernel@vger.kernel.org; kvm@vger.kernel.org > Subject: Re: [PATCH V5 1/2] perf ignore LBR and extra_regs > > Il 14/07/2014 15:36, Liang, Kan ha scritto: > >> > Kan Liang, what happens if CONFIG_PARAVIRT=y? Do you get garbage > >> > or just no events reported? > >> > > > Guest rdmsr/wrmsr will eventually call rdmsr_safe/wrmsr_safe. They will > handle the #GP. So there is no error report in guest. > > Yeah, but what's the effect on the output of perf?
They can be still counted/sampled, but the results are garbage.
Kan
> > Paolo
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