Re: qemu-kvm loops after kernel udpate

[Jiri Slaby]

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.

thanks,
--
js
suse labs
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