From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org, stable@dpdk.org, Ilya Maximets <i.maximets@samsung.com>
Subject: Re: [PATCH 1/8] net/virtio: revert "virtio: fix restart"
Date: Fri, 4 Nov 2016 10:00:05 +0800 [thread overview]
Message-ID: <20161104020005.GV16751@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <915489cd-7e1a-9a0c-ab9d-780f6103501b@redhat.com>
On Thu, Nov 03, 2016 at 09:36:52PM +0100, Maxime Coquelin wrote:
> Hi Yuanhan,
>
> On 11/03/2016 05:09 PM, Yuanhan Liu wrote:
> >This reverts commit 9a0615af7746 ("virtio: fix restart"); conflict is
> >manually addressed.
> >
> >Kyle reported an issue with above commit
> >
> > qemu-kvm: Guest moved used index from 5 to 1
> >
> >with following steps,
> >
> > 1) Start my virtio interfaces
> > 2) Send some traffic into/out of the interfaces
> > 3) Stop the interfaces
> > 4) Start the interfaces
> > 5) Send some more traffic
> >
> >And here are some quotes from Kyle's analysis,
> >
> > Prior to the patch, if an interface were stopped then started, without
> > restarting the application, the queues would be left as-is, because
> > hw->started would be set to 1. Now, calling stop sets hw->started to 0,
> > which means the next call to start will "touch the queues". This is the
> > unintended side-effect that causes the problem.
>
> Maybe a good idea to explain what is the problem the revert aims to fix.
It aims to fix the issue, by "not touching the queues" on restart.
> It does not seem to be clearly stated in the commit message.
I was thinking the quote from Kyle is enough. How about following supplement:
We should not touch the queues once the init is done, otherwise, the
vring state of virtio PMD driver and vhost-user would be inconsistent,
leading some issue like above.
Thus this patch is reverted.
Better now?
--yliu
next prev parent reply other threads:[~2016-11-04 2:00 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-03 16:09 [PATCH 0/8] net/virtio: fix queue reconfigure issue Yuanhan Liu
2016-11-03 16:09 ` [PATCH 1/8] net/virtio: revert "virtio: fix restart" Yuanhan Liu
2016-11-03 20:36 ` Maxime Coquelin
2016-11-04 2:00 ` Yuanhan Liu [this message]
2016-11-04 8:09 ` Maxime Coquelin
2016-11-04 14:28 ` Yuanhan Liu
2016-11-04 8:10 ` Maxime Coquelin
2016-11-03 16:09 ` [PATCH 2/8] net/virtio: simplify queue memzone name Yuanhan Liu
2016-11-03 20:41 ` Maxime Coquelin
2016-11-03 16:09 ` [PATCH 3/8] net/virtio: simplify queue allocation Yuanhan Liu
2016-11-03 20:48 ` Maxime Coquelin
2016-11-04 1:51 ` Yuanhan Liu
2016-11-03 16:09 ` [PATCH 4/8] net/virtio: allocate queue at init stage Yuanhan Liu
2016-11-03 21:11 ` Maxime Coquelin
2016-11-04 1:50 ` Yuanhan Liu
2016-11-04 8:08 ` Maxime Coquelin
2016-11-04 8:25 ` Maxime Coquelin
2016-11-04 15:21 ` Kevin Traynor
2016-11-04 20:30 ` Kevin Traynor
2016-11-05 6:15 ` Yuanhan Liu
2016-11-03 16:09 ` [PATCH 5/8] net/virtio: initiate vring " Yuanhan Liu
2016-11-04 8:34 ` Maxime Coquelin
2016-11-03 16:09 ` [PATCH 6/8] net/virtio: move queue configure code to proper place Yuanhan Liu
2016-11-04 8:39 ` Maxime Coquelin
2016-11-03 16:09 ` [PATCH 7/8] net/virtio: complete init stage at the right place Yuanhan Liu
2016-11-04 8:44 ` Maxime Coquelin
2016-11-03 16:10 ` [PATCH 8/8] net/virtio: remove started field Yuanhan Liu
2016-11-04 8:46 ` Maxime Coquelin
2016-11-05 9:40 ` [PATCH v2 00/10] net/virtio: fix queue reconfigure issue Yuanhan Liu
2016-11-05 9:40 ` [PATCH v2 01/10] net/virtio: revert fix restart Yuanhan Liu
2016-11-05 9:40 ` [PATCH v2 02/10] net/virtio: simplify queue memzone name Yuanhan Liu
2016-11-05 9:40 ` [PATCH v2 03/10] net/virtio: simplify queue allocation Yuanhan Liu
2016-11-05 9:40 ` [PATCH v2 04/10] net/virtio: allocate queue at init stage Yuanhan Liu
2016-11-07 14:23 ` Thomas Monjalon
2016-11-05 9:41 ` [PATCH v2 05/10] net/virtio: initiate vring " Yuanhan Liu
2016-11-05 9:41 ` [PATCH v2 06/10] net/virtio: move queue configure code to proper place Yuanhan Liu
2016-11-05 9:41 ` [PATCH v2 07/10] net/virtio: complete init stage at the right place Yuanhan Liu
2016-11-05 9:41 ` [PATCH v2 08/10] net/virtio: remove started field Yuanhan Liu
2016-11-05 9:41 ` [PATCH v2 09/10] net/virtio: fix less queues being enabled issue Yuanhan Liu
2016-11-05 9:41 ` [PATCH v2 10/10] net/virtio: fix multiple queue enabling Yuanhan Liu
2016-11-07 9:25 ` Yuanhan Liu
2016-11-07 14:44 ` [PATCH v2 00/10] net/virtio: fix queue reconfigure issue Thomas Monjalon
2016-11-07 15:05 ` Yao, Lei A
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