Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: intel_pstate divide error with v3.13-rc4-256-gb7000ad | Date | Fri, 27 Dec 2013 22:51:59 +0100 |
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On Friday, December 27, 2013 06:17:47 PM Kashyap Chamarthy wrote: > On 12/27/2013 06:01 PM, Gleb Natapov wrote: > > On Fri, Dec 27, 2013 at 06:52:48PM +0200, Gleb Natapov wrote: > >> 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? > > Here's host dmesg: https://bugzilla.kernel.org/attachment.cgi?id=119751 > > >> Can you ftrace the failure? > > Can try, need some time (rest of the day I'll be away travelling, > will try to do it over the weekend, and update the Kernel > bugzilla with observations). > > >> > > Ugh, it looks like guest dmesg but there are KVM messages there too ("[ > > 281.443662] kvm [2452]: vcpu0 unhandled rdmsr: 0xe8" is unhandled access > > to MSR_IA32_APERF I was talking about above), so I guess this is nested > > guest invocation? > > Yeah -- sorry, I forgot to note it's in a nested environment :( > > > Does it happen in non nested guest? > > I need to that. > > Note to self: Also try with a newer Kernel on the host.
Please try the patch I posted earlier today when you're at it:
https://patchwork.kernel.org/patch/3411991/
Rafael
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