From: Stefano Brivio <sbrivio@redhat.com>
To: Markus Armbruster <armbru@redhat.com>
Cc: "Laurent Vivier" <lvivier@redhat.com>,
qemu-devel@nongnu.org,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Eric Blake" <eblake@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Laine Stump" <laine@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Daniel P. Berrangé" <berrange@redhat.com>
Subject: Re: [PATCH] net: vhost-user: add QAPI events to report connection state
Date: Fri, 14 Feb 2025 15:13:30 +0100 [thread overview]
Message-ID: <20250214151330.0f0be3dd@elisabeth> (raw)
In-Reply-To: <87a5ao3a3q.fsf@pond.sub.org>
On Fri, 14 Feb 2025 14:54:33 +0100
Markus Armbruster <armbru@redhat.com> wrote:
> Laurent Vivier <lvivier@redhat.com> writes:
>
> > On 14/02/2025 11:06, Markus Armbruster wrote:
> >> Laurent Vivier <lvivier@redhat.com> writes:
> >>
> >>> The netdev reports NETDEV_VHOST_USER_CONNECTED event when
> >>> the chardev is connected, and NETDEV_VHOST_USER_DISCONNECTED
> >>> when it is disconnected.
> >>>
> >>> The NETDEV_VHOST_USER_CONNECTED event includes the ChardevInfo
> >>> (label, filename and frontend_open).
> >>>
> >>> This allows a system manager like libvirt to detect when the server
> >>> fails.
> >>>
> >>> For instance with passt:
> >>>
> >>> { 'execute': 'qmp_capabilities' }
> >>> { "return": { } }
> >>>
> >>> [killing passt here]
> >>>
> >>> { "timestamp": { "seconds": 1739517243, "microseconds": 115081 },
> >>> "event": "NETDEV_VHOST_USER_DISCONNECTED",
> >>> "data": { "netdev-id": "netdev0" } }
> >>>
> >>> [automatic reconnection with reconnect-ms]
> >>>
> >>> { "timestamp": { "seconds": 1739517290, "microseconds": 343777 },
> >>> "event": "NETDEV_VHOST_USER_CONNECTED",
> >>> "data": { "netdev-id": "netdev0",
> >>> "info": { "frontend-open": true,
> >>> "filename": "unix:",
> >>> "label": "chr0" } } }
> >>>
> >>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> >>
> >> Standard question for events: if a management application misses an
> >> event, say because it restarts and reconnects, is there a way to obtain
> >> the missed information with a query command?
> >
> > query-chardev could help but it doesn't provide the netdev id.
> >
> > in HMP, "info network" has the information, but for QMP we had a try with a query-netdev in the past but the series has been reverted.
> >
> > f9bb0c1f9862 ("Revert "qapi: net: Add query-netdev command"")
> > d32ad10a14d4 ("qapi: net: Add query-netdev command")
>
> Hmm. Can management applications use these events without a matching
> query?
Yes, see https://lore.kernel.org/all/20250214095338.344063fa@elisabeth/
and the existing libvirt implementation for NETDEV_STREAM_DISCONNECTED.
--
Stefano
next prev parent reply other threads:[~2025-02-14 14:14 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-14 7:26 [PATCH] net: vhost-user: add QAPI events to report connection state Laurent Vivier
2025-02-14 8:53 ` Stefano Brivio
2025-02-14 10:06 ` Markus Armbruster
2025-02-14 10:18 ` Laurent Vivier
2025-02-14 13:54 ` Markus Armbruster
2025-02-14 14:13 ` Stefano Brivio [this message]
2025-02-14 13:59 ` Daniel P. Berrangé
2025-02-14 14:18 ` Stefano Brivio
2025-02-14 14:19 ` Daniel P. Berrangé
2025-02-14 14:28 ` Stefano Brivio
2025-02-14 14:31 ` Daniel P. Berrangé
2025-02-14 14:38 ` Stefano Brivio
2025-02-17 10:22 ` Laurent Vivier
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=20250214151330.0f0be3dd@elisabeth \
--to=sbrivio@redhat.com \
--cc=armbru@redhat.com \
--cc=berrange@redhat.com \
--cc=eblake@redhat.com \
--cc=jasowang@redhat.com \
--cc=laine@redhat.com \
--cc=lvivier@redhat.com \
--cc=marcandre.lureau@redhat.com \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.