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Re: [Qemu-devel] vhost-user breaks after 96a3d98.
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] vhost-user breaks after 96a3d98. |
Date: |
Wed, 4 Jan 2017 00:13:12 +0200 |
On Tue, Jan 03, 2017 at 03:33:12PM -0200, Flavio Leitner wrote:
> On Tue, 3 Jan 2017 18:28:18 +0800
> Jason Wang <address@hidden> wrote:
>
> > On 2017年01月03日 11:09, Jason Wang wrote:
> > >
> > >
> > > On 2016年12月30日 20:41, Flavio Leitner wrote:
> > >> Hi,
> > >>
> > >> While I was testing vhost-user using OVS 2.5 and DPDK 2.2.0 in the
> > >> host and testpmd dpdk 2.2.0 in the guest, I found that the commit
> > >> below breaks the environment and no packets gets into the guest.
> > >>
> > >> dpdk port --> OVS --> vhost-user --> guest --> testpmd
> > >> ^--- drops here ^--- no packets here.
> > >>
> > >> commit 96a3d98d2cdbd897ff5ab33427aa4cfb94077665
> > >> Author: Jason Wang <address@hidden>
> > >> Date: Mon Aug 1 16:07:58 2016 +0800
> > >>
> > >> vhost: don't set vring call if no vector
> > >> We used to set vring call fd unconditionally even if guest
> > >> driver does
> > >> not use MSIX for this vritqueue at all. This will cause lots of
> > >> unnecessary userspace access and other checks for drivers does
> > >> not use
> > >> interrupt at all (e.g virtio-net pmd). So check and clean vring
> > >> call
> > >> fd if guest does not use any vector for this virtqueue at
> > >> all.
> > >> [...]
> > >>
> > >> Thanks,
> > >
> > > Hi Flavio:
> > >
> > > Thanks for reporting this issue, could this be a bug of vhost-user? (I
> > > believe virito-net pmd does not use interrupt for rx/tx at all)
> > >
> > > Anyway, will try to reproduce it.
> > >
> >
> > Could not reproduce this issue on similar setups (the only difference is
> > I don't create dpdk port) with dpdk 16.11 and ovs.git HEAD. Suspect an
> > issue dpdk. Will try OVS 2.5 + DPDK 2.2.0.
>
> Yeah, that's the combo I am testing and seeing the issue. I found the
> commit after bisecting qemu and then confirmed by testing up to the
> previous commit (works okay) and then the commit above (fails).
>
> I still have my test environment available, so I would be able to test
> any patch you might have.
>
> Thanks,
> --
> Flavio
Could you pls try to test dpdk git head and bisect that to find
what fixes the issue?
--
MST
Re: [Qemu-devel] vhost-user breaks after 96a3d98., Flavio Leitner, 2017/01/03
- Re: [Qemu-devel] vhost-user breaks after 96a3d98.,
Michael S. Tsirkin <=