Re: [Qemu-devel] latest rc: virtio-blk hangs forever after migration

[Marcelo Tosatti <mtosatti@redhat.com>]

On Thu, Sep 04, 2014 at 08:52:00PM +0400, Andrey Korolyov wrote:
> On Thu, Sep 4, 2014 at 8:38 PM, Marcelo Tosatti <mtosatti@redhat.com> wrote:
> > On Sun, Aug 24, 2014 at 10:51:38PM +0400, Andrey Korolyov wrote:
> >> On Sun, Aug 24, 2014 at 8:57 PM, Andrey Korolyov <andrey@xdel.ru> wrote:
> >> > On Sun, Aug 24, 2014 at 8:35 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> >> >> Il 24/08/2014 18:19, Andrey Korolyov ha scritto:
> >> >>> Sorry, I was a bit inaccurate in my thoughts at Fri about necessary
> >> >>> amount of work, patch lays perfectly on 3.10 with bit of monkey
> >> >>> rewrites. The attached one fixed problem for me - it represents
> >> >>> 0b10a1c87a2b0fb459baaefba9cb163dbb8d3344,
> >> >>> 0bc830b05c667218d703f2026ec866c49df974fc,
> >> >>> 44847dea79751e95665a439f8c63a65e51da8e1f and
> >> >>> 673f7b4257a1fe7b181e1a1182ecc2b6b2b795f1.
> >> >>
> >> >> So, with these changes, Marcelo's patch does not hang up your guest anymore?
> >> >>
> >> >> Paolo
> >> >>
> >> >
> >> > If I may reword, Marcelo`s proposed states sync with revert-revert of
> >> > agraf`s patch, does not break anything for Windows (migration works
> >> > well for any variant of emulator with modified kernel modules). Let me
> >> > check if initially reported issue (lost I/O interrupts) is gone for
> >> > the current situation (patched kernel plus Marcelo` patch).
> >>
> >>
> >> patched kernel + any 2.1 variant + Windows = works
> >> patched kernel + patched 2.1 + Linux + disk workload = works fine
> >
> > Andrey,
> >
> > What patch is this again ?
> >
> >
> 
> It is attached to the message which has a highest quoting order above
> 1), basically it is a monkey adaptation of newer ioapic patches for
> 3.10. RH kernel includes them, so Centos7/RH7 users should not observe
> reported problem.
> 
> [1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg252526.html
> 
> Using the opportunity - what are plans, if there are any, to revive
> agraf`s patch which was the reason of an initial issue in this thread?
> The Windows issue is most probably unrelated to it and I`d be happy to
> check patch proposals because there are a lot of suffering with VMs
> with large uptime and live migration when negative time shift appears.

I'll try to confirm via Marcin's testcase (vfio+VM migration on Linux guests), 
that the proposed patch is fixing the issue.

Getting a BSOD on Win2008-R2-x64 while trying to install virtio-win
driver (viostor related BSOD).