[ovs-dev] [PATCH V4 2/2] netdev-dpdk: vHost IOMMU support

[Mooney, Sean K]

> -----Original Message-----
> From: Jan Scheurich [mailto:jan.scheurich at ericsson.com]
> Sent: Thursday, December 7, 2017 3:09 PM
> To: Kevin Traynor <ktraynor at redhat.com>; Kavanagh, Mark B
> <mark.b.kavanagh at intel.com>; Ilya Maximets <i.maximets at samsung.com>;
> Stokes, Ian <ian.stokes at intel.com>; dev at openvswitch.org
> Cc: maxime.coquelin at redhat.com; Mooney, Sean K
> <sean.k.mooney at intel.com>; Fischetti, Antonio
> <antonio.fischetti at intel.com>; Bie, Tiwei <tiwei.bie at intel.com>;
> Mcnamara, John <john.mcnamara at intel.com>; Guoshuai Li
> <ligs at dtdream.com>; Loftus, Ciara <ciara.loftus at intel.com>; Yuanhan Liu
> <yliu at fridaylinux.org>
> Subject: RE: [ovs-dev] [PATCH V4 2/2] netdev-dpdk: vHost IOMMU support
> 
> > > I think the point that both yourself and Sean has made is
> completely valid, which puts option a) back on the table.
> > >
> >
> > a) Sounds ok to me. I think an early DPDK17.11.1 before OVS 2.9 would
> > be good in addition though. It is nicer that an OVS 2.9 user doesn't
> > have to know they can't use the latest DPDK in the guest.
> >
> 
> Would the virtio PMD bug in DPDK 17.11 in the guest actually be
> mitigated by running DPDK 17.05 or a fixed 17.11.1 as vhostuser backend
> inside OVS on the host?
[Mooney, Sean K] from talking to mark about this eairlier I don’t belive so.
I think if you used 17.11 testpmd in the guest with kernel ovs you should
get the same behavior e.g. it does not forward packet. The guest should not
be able to know with certainty what vhost backend is in use on the host.
> 
> If not, I would prefer if we decoupled the DPDK life cycle of OVS and
> DPDK applications in the guest. Guests should update their DPDK version
> if  it contains a critical bug.
> 
> BR, Jan
>