From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: "Charles (Chas) Williams" <ciwillia@brocade.com>
Cc: dev@dpdk.org, mtetsuyah@gmail.com
Subject: Re: [dpdk-dev] [PATCH 2/2] vhost: start vhost servers once
Date: Fri, 30 Dec 2016 11:15:01 +0800 [thread overview]
Message-ID: <20161230031501.GE21789@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <bd70f0c1-cb57-728a-2f94-84e688c89648@brocade.com>
On Thu, Dec 29, 2016 at 10:58:11AM -0500, Charles (Chas) Williams wrote:
> On 12/29/2016 03:52 AM, Yuanhan Liu wrote:
> >On Wed, Dec 28, 2016 at 04:10:52PM -0500, Charles (Chas) Williams wrote:
> >>Start a vhost server once during devinit instead of during device start
> >>and stop. Some vhost clients, QEMU, don't re-attaching to sockets when
> >>the vhost server is stopped and later started. Preserve existing behavior
> >>for vhost clients.
> >
> >I didn't quite get the idea what you are going to fix.
>
> The issue I am trying to fix is QEMU interaction when DPDK's vhost is
> acting as a server to QEMU vhost clients. If you create a vhost server
> device, it doesn't create the actual datagram socket until you call
> .dev_start(). If you call .dev_stop() is also deletes those sockets.
> For QEMU, this is a problem since QEMU doesn't know how to re-attach to
> datagram sockets that have gone away.
Thanks! And I'd appreciate it if you could have written the commit log
this way firstly.
> .dev_start()/.dev_stop() seems to roughly means link up and link down
> so I understand why you might want to add/remove the datagram sockets.
> However, in practice, this doesn't seem to make much sense for a DPDK
> vhost server.
Agree.
> This doesn't seem like the right way to indicate link
> status to vhost clients.
>
> It seems like it would just be easier to do this for both clients and
> servers, but I don't know why it was done this way originally so I
> choose to keep the client behavior.
I don't think there are any differences between DPDK acting as client or
server. To me, the right logic seems to be (for both DPDK as server and
client).
For register,
- register the vhost socket at probe stage (either at rte_pmd_vhost_probe
or at eth_dev_vhost_create).
- start the vhost session right after the register when we haven't started
it before.
For unregister,
- invoke rte_vhost_driver_unregister() at rte_pmd_vhost_remove().
For dev_start/stop,
- set allow_queuing to 1/0 for start/stop, respectively.
--yliu
next prev parent reply other threads:[~2016-12-30 3:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-28 21:10 [dpdk-dev] [PATCH 1/2] vhost: reference count fix for nb_started_ports Charles (Chas) Williams
2016-12-28 21:10 ` [dpdk-dev] [PATCH 2/2] vhost: start vhost servers once Charles (Chas) Williams
2016-12-29 8:52 ` Yuanhan Liu
2016-12-29 15:58 ` Charles (Chas) Williams
2016-12-30 3:15 ` Yuanhan Liu [this message]
2016-12-30 21:26 ` Charles (Chas) Williams
2017-01-03 8:16 ` Yuanhan Liu
2016-12-29 8:51 ` [dpdk-dev] [PATCH 1/2] vhost: reference count fix for nb_started_ports Yuanhan Liu
2016-12-29 15:49 ` Charles (Chas) Williams
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161230031501.GE21789@yliu-dev.sh.intel.com \
--to=yuanhan.liu@linux.intel.com \
--cc=ciwillia@brocade.com \
--cc=dev@dpdk.org \
--cc=mtetsuyah@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).