Re: qemu-kvm loops after kernel udpate

[Andrew Morton]

On Tue, 18 Sep 2012 21:40:31 +0200
Jiri Slaby <jslaby@xxxxxxx> wrote:

> On 09/13/2012 11:59 AM, Avi Kivity wrote:
> > On 09/12/2012 09:11 PM, Jiri Slaby wrote:
> >> On 09/12/2012 10:18 AM, Avi Kivity wrote:
> >>> On 09/12/2012 11:13 AM, Jiri Slaby wrote:
> >>>>
> >>>>>   Please provide the output of vmxcap
> >>>>> (http://goo.gl/c5lUO),
> >>>>
> >>>>    Unrestricted guest                       no
> >>>
> >>> The big real mode fixes.
> >>>
> >>>
> >>>>
> >>>>> and a snapshot of kvm_stat while the guest is hung.
> >>>>
> >>>> kvm statistics
> >>>>
> >>>>   exits                                      6778198  615942
> >>>>   host_state_reload                             1988     187
> >>>>   irq_exits                                     1523     138
> >>>>   mmu_cache_miss                                   4       0
> >>>>   fpu_reload                                       1       0
> >>>
> >>> Please run this as root so we get the tracepoint based output; and press
> >>> 'x' when it's running so we get more detailed output.
> >>
> >> kvm statistics
> >>
> >>   kvm_exit                                  13798699  330708
> >>   kvm_entry                                 13799110  330708
> >>   kvm_page_fault                            13793650  330604
> >>   kvm_exit(EXCEPTION_NMI)                    6188458  330604
> >>   kvm_exit(EXTERNAL_INTERRUPT)                  2169     105
> >>   kvm_exit(TPR_BELOW_THRESHOLD)                   82       0
> >>   kvm_exit(IO_INSTRUCTION)                         6       0
> >
> > Strange, it's unable to fault in the very first page.
> 
> I bisected that. Note the bisection log. I have never seen something 
> like that :D:
> git bisect start
> git bisect bad 3de9d1a1500472bc80478bd75e33fa9c1eba1422
> git bisect good fea7a08acb13524b47711625eebea40a0ede69a0
> git bisect good 95a2fe4baa1ad444df5f94bfc9416fc6b4b34cef
> git bisect good f42c0d57a5a60da03c705bdea9fbba381112dd60
> git bisect good 31a2e241a9e37a133278959044960c229acc5714
> git bisect good f15fb01c5593fa1b58cc7a8a9c59913e2625bf2e
> git bisect good 16d21ff46f5d50e311d07406c31f96916e5e8e1a
> git bisect good 0b84592f458b4e8567aa7d803aff382c1d3b64fd
> git bisect bad b955428e7f14cd29fe9d8059efa3ea4be679c83d
> git bisect bad 20c4da4f68fcade05eda9c9b7dbad0a78cc5efe8
> git bisect bad 31b90ed2a90f80fb528ac55ee357a815e1dedc36
> git bisect bad b273fe14ee5b38cecc7bce94f7777f35a0bf9ee4
> git bisect bad de426dbe9a60706b91b40397f69f819a39a06b6b
> git bisect bad 6b998094ec50248e72b9f251d0607b58b18dba38
> git bisect bad cf9b81d47a89f5d404a0cd8013b461617751e520
> 
> === 8< ===
> 
> Reverting cf9b81d47a89 (mm: wrap calls to set_pte_at_notify with 
> invalidate_range_start and invalidate_range_end) on the top of today's 
> -next fixes the issue.

hm, thanks.  This will probably take some time to resolve so I think
I'll drop

mm-move-all-mmu-notifier-invocations-to-be-done-outside-the-pt-lock.patch
mm-move-all-mmu-notifier-invocations-to-be-done-outside-the-pt-lock-fix.patch
mm-move-all-mmu-notifier-invocations-to-be-done-outside-the-pt-lock-fix-fix.patch
mm-wrap-calls-to-set_pte_at_notify-with-invalidate_range_start-and-invalidate_range_end.patch
 
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