From: "Daniel P. Berrangé" <berrange@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>,
Juan Quintela <quintela@redhat.com>,
Jason Wang <jasowang@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v2 01/27] migration: Network Failover can't work with a paused guest
Date: Wed, 2 Dec 2020 10:27:18 +0000 [thread overview]
Message-ID: <20201202102718.GA2360260@redhat.com> (raw)
In-Reply-To: <20201202050918-mutt-send-email-mst@kernel.org>
On Wed, Dec 02, 2020 at 05:13:18AM -0500, Michael S. Tsirkin wrote:
> On Wed, Nov 18, 2020 at 09:37:22AM +0100, Juan Quintela wrote:
> > If we have a paused guest, it can't unplug the network VF device, so
> > we wait there forever. Just change the code to give one error on that
> > case.
> >
> > Signed-off-by: Juan Quintela <quintela@redhat.com>
>
> It's certainly possible but it's management that created
> this situation after all - why do we bother to enforce
> a policy? It is possible that management will unpause immediately
> afterwards and everything will proceed smoothly.
>
> Yes migration will not happen until guest is
> unpaused but the same it true of e.g. a guest that is stuck
> because of a bug.
That's pretty different behaviour from how migration normally handles
a paused guest, which is that it is guaranteed to complete the migration
in as short a time as network bandwidth allows.
Just ignoring the situation I think will lead to surprise apps / admins,
because the person/entity invoking the migration is not likely to have
checked wether this particular guest uses net failover or not before
invoking - they'll just be expecting a paused migration to run fast and
be guaranteed to complete.
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
next prev parent reply other threads:[~2020-12-02 10:57 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-18 8:37 [PATCH v2 00/27] Virtio net failover fixes Juan Quintela
2020-11-18 8:37 ` [PATCH v2 01/27] migration: Network Failover can't work with a paused guest Juan Quintela
2020-11-25 12:05 ` Dr. David Alan Gilbert
2020-12-02 10:13 ` Michael S. Tsirkin
2020-12-02 10:27 ` Daniel P. Berrangé [this message]
2020-12-02 10:31 ` Michael S. Tsirkin
2020-12-02 10:33 ` Michael S. Tsirkin
2020-12-02 10:51 ` Juan Quintela
2020-12-02 10:55 ` Daniel P. Berrangé
2020-12-02 11:19 ` Michael S. Tsirkin
2020-12-02 11:26 ` Daniel P. Berrangé
2020-12-02 11:37 ` Michael S. Tsirkin
2020-12-02 12:01 ` Daniel P. Berrangé
2020-12-03 11:21 ` Michael S. Tsirkin
2020-12-03 11:32 ` Daniel P. Berrangé
2020-12-03 11:40 ` Michael S. Tsirkin
2020-12-03 11:43 ` Dr. David Alan Gilbert
2020-12-03 12:02 ` Michael S. Tsirkin
2020-12-03 12:04 ` Dr. David Alan Gilbert
2020-12-03 12:11 ` Michael S. Tsirkin
2020-12-03 12:16 ` Daniel P. Berrangé
2020-12-08 18:48 ` Michael S. Tsirkin
2020-12-03 11:45 ` Daniel P. Berrangé
2020-12-03 12:01 ` Michael S. Tsirkin
2020-12-03 12:06 ` Daniel P. Berrangé
2020-12-03 12:13 ` Michael S. Tsirkin
2020-12-08 18:32 ` Michael S. Tsirkin
2020-12-02 10:34 ` Daniel P. Berrangé
2020-11-18 8:37 ` [PATCH v2 02/27] failover: fix indentantion Juan Quintela
2020-11-18 8:37 ` [PATCH v2 03/27] failover: Use always atomics for primary_should_be_hidden Juan Quintela
2020-11-18 8:37 ` [PATCH v2 04/27] failover: primary bus is only used once, and where it is set Juan Quintela
2020-11-18 8:37 ` [PATCH v2 05/27] failover: Remove unused parameter Juan Quintela
2020-11-18 8:37 ` [PATCH v2 06/27] failover: Remove external partially_hotplugged property Juan Quintela
2020-11-18 8:37 ` [PATCH v2 07/27] failover: qdev_device_add() returns err or dev set Juan Quintela
2020-11-18 8:37 ` [PATCH v2 08/27] failover: Rename bool to failover_primary_hidden Juan Quintela
2020-11-18 8:37 ` [PATCH v2 09/27] failover: g_strcmp0() knows how to handle NULL Juan Quintela
2020-11-18 8:37 ` [PATCH v2 10/27] failover: Remove primary_device_opts Juan Quintela
2020-11-18 8:37 ` [PATCH v2 11/27] failover: remove standby_id variable Juan Quintela
2020-11-18 8:37 ` [PATCH v2 12/27] failover: Remove primary_device_dict Juan Quintela
2020-11-18 8:37 ` [PATCH v2 13/27] failover: Remove memory leak Juan Quintela
2020-11-18 8:37 ` [PATCH v2 14/27] failover: simplify virtio_net_find_primary() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 15/27] failover: should_be_hidden() should take a bool Juan Quintela
2020-11-18 8:37 ` [PATCH v2 16/27] failover: Rename function to hide_device() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 17/27] failover: virtio_net_connect_failover_devices() does nothing Juan Quintela
2020-11-18 8:37 ` [PATCH v2 18/27] failover: Rename to failover_find_primary_device() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 19/27] failover: simplify qdev_device_add() failover case Juan Quintela
2020-11-18 8:37 ` [PATCH v2 20/27] failover: simplify qdev_device_add() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 21/27] failover: make sure that id always exist Juan Quintela
2020-11-18 8:37 ` [PATCH v2 22/27] failover: remove failover_find_primary_device() error parameter Juan Quintela
2020-11-18 8:37 ` [PATCH v2 23/27] failover: split failover_find_primary_device_id() Juan Quintela
2020-11-18 8:37 ` [PATCH v2 24/27] failover: We don't need to cache primary_device_id anymore Juan Quintela
2020-11-18 8:37 ` [PATCH v2 25/27] failover: Caller of this two functions already have primary_dev Juan Quintela
2020-11-18 8:37 ` [PATCH v2 26/27] failover: simplify failover_unplug_primary Juan Quintela
2020-11-18 8:37 ` [PATCH v2 27/27] failover: Remove primary_dev member Juan Quintela
2020-11-18 8:53 ` [PATCH v2 00/27] Virtio net failover fixes Michael S. Tsirkin
2020-12-02 10:16 ` Juan Quintela
2020-12-02 10:30 ` Michael S. Tsirkin
2020-12-02 9:55 ` Michael S. Tsirkin
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=20201202102718.GA2360260@redhat.com \
--to=berrange@redhat.com \
--cc=dgilbert@redhat.com \
--cc=ehabkost@redhat.com \
--cc=jasowang@redhat.com \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=quintela@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).