From: Kevin Wolf <kwolf@redhat.com>
To: Coiby Xu <coiby.xu@gmail.com>
Cc: bharatlkmlkvm@gmail.com, qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [PATCH v2 3/5] a standone-alone tool to directly share disk image file via vhost-user protocol
Date: Sun, 2 Feb 2020 10:33:36 +0100 [thread overview]
Message-ID: <20200202093336.GB3456@localhost.localdomain> (raw)
In-Reply-To: <CAJAkqrUYp7uCH80Ui0S4GXnAaKasNGPAYM5oJEjC2LuJ02cfPg@mail.gmail.com>
Am 31.01.2020 um 17:42 hat Coiby Xu geschrieben:
> > Yes, I think at least for the moment it should work fine this way.
> > Eventually, I'd like to integrate it with --export (and associated QMP
> > commands, which are still to be created), too. Maybe at that point we
> > want to make the QOM object not user creatable any more.
>
> Does it mean TYPE_USER_CREATABLE interface in QOM will become
> deprecated in the future? I'm curious what are the reasons for making
> QOM object no user creatable? Because we may still need to start
> vhost-user block device backend through HMP or QMP instead of stating
> it as a standalone-alone daemon.
Not in general, but if we have something like a block-export-add QMP
command, the QOM interface would be redundant. We could still leave it
there and have both a low-level and a high-level interface, but whether
we would want to is something we still have to decide.
> > As for test cases, do you think it would be hard to just modify the
> > tests to send an explicit 'quit' command to the daemon?
>
> Accroding to https://patchew.org/QEMU/20191017130204.16131-1-kwolf@redhat.com/20191017130204.16131-10-kwolf@redhat.com/,
>
> > +static bool exit_requested = false;
> > +
> > +void qemu_system_killed(int signal, pid_t pid)
> > +{
> > + exit_requested = true;
> > +}
>
> if exit_requested = true, qemu-storage-daemon will exit the main loop
> and then quit. So is calling qemu_system_killed by what you means "to
> send an explicit 'quit' command to the daemon"?
qemu_system_killed() is call in the signal handlers for, amongst others,
SIGTERM and SIGINT. This is one way to stop the storage daemon (for
manual use, sending SIGINT with Ctrl-C is probably the easiest way).
What I actually meant is the 'quit' QMP command which will cause
qmp_quit() to be run, which contains the same code. But if sending a
signal is more convenient, that's just as good.
Kevin
> On Fri, Jan 17, 2020 at 6:12 PM Kevin Wolf <kwolf@redhat.com> wrote:
> >
> > Am 17.01.2020 um 09:12 hat Coiby Xu geschrieben:
> > > Excellent! I will add an option (or object property) for
> > > vhost-user-blk server oject which will tell the daemon process to exit
> > > when the client disconnects, thus "make check-qtest" will not get held
> > > by this daemon process. After that since Kevin's qemu-storage-daemon
> > > support "-object" option
> > > (https://patchew.org/QEMU/20191017130204.16131-1-kwolf@redhat.com/20191017130204.16131-3-kwolf@redhat.com/)
> > > and vhost-user-server is a user-creatable QOM object, it will work out
> > > of the box.
> >
> > Yes, I think at least for the moment it should work fine this way.
> > Eventually, I'd like to integrate it with --export (and associated QMP
> > commands, which are still to be created), too. Maybe at that point we
> > want to make the QOM object not user creatable any more.
> >
> > Would it make sense to prefix the object type name with "x-" so we can
> > later retire it from the external user interface without a deprecation
> > period?
> >
> > As for test cases, do you think it would be hard to just modify the
> > tests to send an explicit 'quit' command to the daemon?
> >
> > > I'm curious when will be formal version of qemu-storage-daemon
> > > finished so I can take advantage of it? Or should I apply the RFC
> > > PATCHes to my working branch directly and submit them together with
> > > the patches on vhost-user-blk server feature when posting v3?
> >
> > It's the next thing I'm planning to work on after completing the
> > coroutine-base QMP handlers (which I hope to get finished very soon).
> >
> > For the time being I would suggest that you put any patches that depend
> > on qemu-storage-daemon (if you do need it) at the end of your series so
> > that we could apply the first part even if the storage daemon isn't in
> > yet.
> >
> > The latest version of my patches is at:
> >
> > git://repo.or.cz/qemu/kevin.git storage-daemon
> >
> > But if you just need something for testing your code, I think it would
> > even make sense if you kept your standalone tool around (even though
> > we'll never merge it) and we'll deal with integration in the storage
> > daemon once both parts are ready.
> >
> > Kevin
> >
>
>
> --
> Best regards,
> Coiby
>
next prev parent reply other threads:[~2020-02-02 9:34 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 14:06 [PATCH v2 0/5] vhost-user block device backend implementation Coiby Xu
2020-01-14 14:06 ` [PATCH v2 1/5] vhost-user block device backend Coiby Xu
2020-01-16 13:51 ` Stefan Hajnoczi
2020-01-16 14:20 ` Kevin Wolf
2020-02-14 3:07 ` Coiby Xu
2020-01-16 13:56 ` Kevin Wolf
2020-02-20 7:04 ` Coiby Xu
2020-02-20 9:30 ` Coiby Xu
2020-01-14 14:06 ` [PATCH v2 2/5] extend libvhost to support IOThread Coiby Xu
2020-01-14 14:06 ` [PATCH v2 3/5] a standone-alone tool to directly share disk image file via vhost-user protocol Coiby Xu
2020-01-16 14:04 ` Stefan Hajnoczi
2020-01-17 8:12 ` Coiby Xu
2020-01-17 10:11 ` Kevin Wolf
2020-01-31 16:42 ` Coiby Xu
2020-02-02 9:33 ` Kevin Wolf [this message]
2020-02-13 1:00 ` Coiby Xu
2020-01-14 14:06 ` [PATCH v2 4/5] new qTest case for the vhost-user-blk device backend Coiby Xu
2020-01-14 14:06 ` [PATCH v2 5/5] building configuration files changes Coiby Xu
2020-01-16 11:07 ` Kevin Wolf
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=20200202093336.GB3456@localhost.localdomain \
--to=kwolf@redhat.com \
--cc=bharatlkmlkvm@gmail.com \
--cc=coiby.xu@gmail.com \
--cc=qemu-devel@nongnu.org \
--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).