From: "Michael S. Tsirkin" <mst@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>,
Changpeng Liu <changpeng.liu@intel.com>,
qemu-devel@nongnu.org, marcandre.lureau@redhat.com,
felipe@nutanix.com, james.r.harris@intel.com
Subject: Re: [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space
Date: Tue, 21 Nov 2017 05:12:58 +0200 [thread overview]
Message-ID: <20171121051156-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <776f5005-8bb8-773a-1f16-56b5675e7d74@redhat.com>
On Tue, Nov 21, 2017 at 01:16:12AM +0100, Paolo Bonzini wrote:
> On 20/11/2017 21:44, Michael S. Tsirkin wrote:
> > Live migrations is supposed to be migrating guest writeable state too.
> > If you mean migrating RO fields like size, then
> > I don't think it's a good idea to reuse SET_CONFIG for that.
> > SET_CONFIG should obey exactly the virtio semantics.
> >
> > And I agree, it should say that slave must treat it as a write,
> > and get config as a read according to virtio semantics.
> >
> > If someone needs to pass configuration from qemu to
> > slave, let's add specific messages with precisely defined semantics.
>
> Fair enough, but I'd add nevertheless a 32-bit flags field to both
> GET_CONFIG and SET_CONFIG, and document that the slave MUST check that
> it is zero and otherwise fail.
>
> Paolo
We generally just use protocol feature bits for extensions.
But I have no problem with reserved padding if desired
which seems to be what's described here.
--
MST
next prev parent reply other threads:[~2017-11-21 3:13 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-16 20:44 [Qemu-devel] [PATCH v5 0/4] *** Introduce a new vhost-user-blk host device to Qemu *** Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 1/4] vhost-user: add new vhost user messages to support virtio config space Changpeng Liu
2017-11-20 16:26 ` Stefan Hajnoczi
2017-11-20 20:44 ` Michael S. Tsirkin
2017-11-21 0:16 ` Paolo Bonzini
2017-11-21 3:12 ` Michael S. Tsirkin [this message]
2017-11-22 14:36 ` Paolo Bonzini
2017-11-22 2:27 ` Liu, Changpeng
2017-11-22 2:28 ` Liu, Changpeng
2017-11-22 2:25 ` Liu, Changpeng
2017-11-22 14:49 ` Michael S. Tsirkin
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 2/4] vhost-user-blk: introduce a new vhost-user-blk host device Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 3/4] contrib/libvhost-user: enable virtio config space messages Changpeng Liu
2017-11-16 20:44 ` [Qemu-devel] [PATCH v5 4/4] contrib/vhost-user-blk: introduce a vhost-user-blk sample application Changpeng Liu
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=20171121051156-mutt-send-email-mst@kernel.org \
--to=mst@redhat.com \
--cc=changpeng.liu@intel.com \
--cc=felipe@nutanix.com \
--cc=james.r.harris@intel.com \
--cc=marcandre.lureau@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@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 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.