Re: intel_pstate divide error with v3.13-rc4-256-gb7000ad

From: Gleb Natapov
Date: Fri Dec 27 2013 - 11:53:00 EST


On Fri, Dec 27, 2013 at 03:15:39PM +0100, Kashyap Chamarthy wrote:
> [. . .]
>
> >> KVM does not emulate P-states at all. intel_pstate_init() calls
> >> intel_pstate_msrs_not_valid() before printing "Intel P-state driver
> >> initializing." which suppose to fail since it checks that two reads of
> >> MSR_IA32_APERF return different values, but KVM does not emulate this msr
> >> at all, so both calls should return zero (KVM suppose to inject #GP, all rdmsrl
> >> are patched to be rdmsrl_safe in a guest).
> >>
> >> Anything interesting in host dmesg?
>
> Heya Gleb,
>
> Here's the relevant dmesg snippet (full dmesg, refer the attachment below):
That's guest dmesg. What about host one? Can you ftrace the failure?

--
Gleb.
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