From: Ilya Maximets <i.maximets@ovn.org>
To: Ilya Maximets <i.maximets@ovn.org>,
Stefan Hajnoczi <stefanha@redhat.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>,
Chenbo Xia <chenbo.xia@intel.com>,
dev@dpdk.org, Adrian Moreno <amorenoz@redhat.com>,
Julia Suvorova <jusual@redhat.com>
Subject: Re: [dpdk-dev] [RFC 0/4] SocketPair Broker support for vhost and virtio-user.
Date: Fri, 19 Mar 2021 17:45:46 +0100 [thread overview]
Message-ID: <4f26e9a9-8dd1-f619-4337-dcecf35d9f3b@ovn.org> (raw)
In-Reply-To: <ee5e0d95-1684-c283-c48c-c45cc2bec57b@ovn.org>
On 3/19/21 5:11 PM, Ilya Maximets wrote:
> On 3/19/21 3:39 PM, Stefan Hajnoczi wrote:
>> Hi Ilya,
>> By the way, it's not clear to me why dpdkvhostuser is deprecated. If OVS
>> is restarted then existing vhost-user connections drop with an error but
>> QEMU could attempt to reconnect to the UNIX domain socket which the new
>> OVS instance will set up.
>>
>> Why is it impossible to reconnect when OVS owns the listen socket?
>
> Well, AFAIK, qemu reconnects client connections only:
>
> ``reconnect`` sets the timeout for reconnecting on non-server
> sockets when the remote end goes away. qemu will delay this many
> seconds and then attempt to reconnect. Zero disables reconnecting,
> and is the default.
>
> I'm not sure about exact reason. It was historically this way.
> For me it doesn't make much sense. I mean, your right that it's
> just a socket, so it should not matter who listens and who connects.
> If reconnection is possible in one direction, it should be possible
> in the opposite direction too.
Sorry, my thought slipped. :) Yes, QEMU supports re-connection
for client sockets. So, in theory, dpdkvhostuser ports should work
after re-connection. And that would be nice. I don't remember
right now why this doesn't work... Maybe vhost-user parts in QEMU
doesn't handle this case. Need to dig some more into that and refresh
my memory. It was so long ago...
Maxime, do you remember?
>
> dpdkvhostuser was deprecated just to scare users and force them to
> migrate to dpdkvhostuserclient and avoid constant bug reports like:
>
> "OVS service restarted and network is lost now".
>
> BTW, virtio-user ports in DPDK doesn't support re-connection in client
> mode too.
This is still true, though. virtio-user in client mode doesn't reconnect.
>
> BTW2, with SocketPair Broker it might be cheaper to implement server
> reconnection in QEMU because all connections in these case are client
> connections, i.e. both ends will connect() to a broker.
>
> Bets regards, Ilya Maximets.
>
next prev parent reply other threads:[~2021-03-19 16:45 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 20:25 Ilya Maximets
2021-03-17 20:25 ` [dpdk-dev] [PATCH 1/4] net/virtio: fix interrupt unregistering for listening socket Ilya Maximets
2021-03-25 8:32 ` Maxime Coquelin
2021-04-07 7:21 ` Xia, Chenbo
2021-03-17 20:25 ` [dpdk-dev] [RFC 2/4] vhost: add support for SocketPair Broker Ilya Maximets
2021-03-17 20:25 ` [dpdk-dev] [RFC 3/4] net/vhost: " Ilya Maximets
2021-03-17 20:25 ` [dpdk-dev] [RFC 4/4] net/virtio: " Ilya Maximets
2021-03-18 17:52 ` [dpdk-dev] [RFC 0/4] SocketPair Broker support for vhost and virtio-user Stefan Hajnoczi
2021-03-18 19:47 ` Ilya Maximets
2021-03-18 20:14 ` Ilya Maximets
2021-03-19 14:16 ` Stefan Hajnoczi
2021-03-19 15:37 ` Ilya Maximets
2021-03-19 16:01 ` Stefan Hajnoczi
2021-03-19 16:02 ` Marc-André Lureau
2021-03-19 8:51 ` Marc-André Lureau
2021-03-19 11:25 ` Ilya Maximets
2021-03-19 14:05 ` Stefan Hajnoczi
2021-03-19 15:29 ` Ilya Maximets
2021-03-19 17:21 ` Stefan Hajnoczi
2021-03-23 17:57 ` Adrian Moreno
2021-03-23 18:27 ` Ilya Maximets
2021-03-23 20:54 ` Billy McFall
2021-03-24 12:05 ` Stefan Hajnoczi
2021-03-24 13:11 ` Ilya Maximets
2021-03-24 15:07 ` Stefan Hajnoczi
2021-03-25 9:35 ` Stefan Hajnoczi
2021-03-25 11:00 ` Ilya Maximets
2021-03-25 16:43 ` Stefan Hajnoczi
2021-03-25 17:58 ` Ilya Maximets
2021-03-30 15:01 ` Stefan Hajnoczi
2021-03-19 14:39 ` Stefan Hajnoczi
2021-03-19 16:11 ` Ilya Maximets
2021-03-19 16:45 ` Ilya Maximets [this message]
2021-03-24 20:56 ` Maxime Coquelin
2021-03-24 21:39 ` Ilya Maximets
2021-03-24 21:51 ` Maxime Coquelin
2021-03-24 22:17 ` Ilya Maximets
2023-06-30 3:45 ` Stephen Hemminger
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=4f26e9a9-8dd1-f619-4337-dcecf35d9f3b@ovn.org \
--to=i.maximets@ovn.org \
--cc=amorenoz@redhat.com \
--cc=chenbo.xia@intel.com \
--cc=dev@dpdk.org \
--cc=jusual@redhat.com \
--cc=maxime.coquelin@redhat.com \
--cc=stefanha@redhat.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).