Re: Re: Still struggling with HVM: tx timeouts on emulated nics

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Wed, 5 Oct 2011, Stefan Bader wrote:
> On 03.10.2011 19:24, Stefano Stabellini wrote:
> > I am going to send a different patch upstream for Xen 4.2, because I
> > would also like it to cover the very unlikely scenario in which a PV
> > guest (like dom0 or a PV guest with PCI passthrough) is loosing level
> > interrupts because when Xen tries to set the corresponding event channel
> > pending the bit is alreay set. The codebase is different enough that
> > making the same change on 4.1 is non-trivial. I am appending the new
> > patch to this email, it would be great if you could test it. You just
> > need a 4.2 hypervisor, not the entire system. You should be able to
> > perform the test updating only xen.gz.
> > If you have trouble if xen-unstable.hg tip, try changeset 23843.
> 
> Hi Stefano,
> 
> currently I would have the problem that I don't have too much time to move to
> another hypervisor (tests may or may not be useful there with substantial
> changes beside this one) with our next release being close.
> But I think I got a usable backport of your change to 4.1.1 (you think it looks
> ok?) and have given that a quick test which seems to be ok...
> Though one drawback is that I don't have a setup which would use passthrough, so
> that path is not tested. I think I did see (with a debugging version) that the
> lost count was incremented and decremented in dom0, though.
> 

Honestly if you have to commit to a backport for your package right now,
I would go for the previous version, because it is simpler and less
likely to introduce regressions.