[dpdk-dev] [PATCH] vhost: fix MQ fails to startup

[Yang, Zhiyong]

Hi, Maxime:

> -----Original Message-----
> From: Maxime Coquelin [mailto:maxime.coquelin at redhat.com]
> Sent: Thursday, April 27, 2017 4:05 PM
> To: Yang, Zhiyong <zhiyong.yang at intel.com>; dev at dpdk.org
> Cc: yuanhan.liu at linux.intel.com; Loftus, Ciara <ciara.loftus at intel.com>; Marc-
> André Lureau <mlureau at redhat.com>
> Subject: Re: [PATCH] vhost: fix MQ fails to startup
> 
> 
> 
> On 04/27/2017 09:56 AM, Maxime Coquelin wrote:
> > Hi Zhiyong,
> >
> > +Marc-André
> >
> > On 04/27/2017 08:34 AM, Zhiyong Yang wrote:
> >> vhost since dpdk17.02 + qemu2.7 and above will cause failures of new
> >> connection when negotiating to set MQ. (one queue pair works
> >> well).Because there exist some bugs in qemu code when introducing
> >> VHOST_USER_PROTOCOL_F_REPLY_ACK to qemu. when dealing with the
> vhost
> >> message VHOST_USER_SET_MEM_TABLE for the second time, qemu indeed
> >> doesn't send the messge (The message needs to be sent only once)but
> >> still will be waiting for dpdk's reply ack, then, qemu is always
> >> freezing. DPDK code works in the right way.
> >
> > I'm looking at Qemu's vhost_user_set_mem_table() function, but fail to
> > see how it could wait for the reply-ack if it didn't send the
> > VHOST_USER_SET_MEM_TABLE request before.
> 
> Oh, sorry, I get it now.
> Are you working for a fix in Qemu, or have you already reported the problem?

I will send bug fix patch to Qemu. 
The same wrong code has also been used when Qemu2.9 introduce the MTU negotiation with DPDK.
I will fix them at the same time in qemu.

Thanks
Zhiyong

> 
> Thanks,
> Maxime