Re: [Qemu-devel] [RFC PATCH v2 00/35] Initial support of multi-process qemu

["Daniel P. Berrangé" <berrange@redhat.com>]

On Mon, Jun 17, 2019 at 11:14:50AM -0700, elena.ufimtseva@oracle.com wrote:
> From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> 
> Initial support of multi-process qemu
> 
> Started with the presentation in October 2017 made by
> Marc-Andre (Red Hat) and Konrad Wilk (Oracle)
> (http://events17.linuxfoundation.org/sites/events/files/slides/KVM%20FORUM%20multi-process.pdf,
> https://www.youtube.com/watch?v=Kq1-coHh7lg) and
> continued in the BoF session at the KVM forum in 2018 with Jag leading
> the discussion, the multi-process project is now in the prototype version
> and presented by this patchset.
> 
> The proof of the concept patches were posted on the qemu-devel mailing
> list before the BoF session at the KVM forum and can be found here:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg566538.html
> 
> This series presents the initial support for QEMU that can
> launch some of the devices in the remote processes.
> 
> Thanks to a v1 review and some of the question Stefan and Daniel asked, we
> were able to incorporate your ideas into our goals.
> 
> We would like to present version 2 of the patchset.
> This version has addressed comments made during the review of v1 and includes:
> 
> - support for libvirt fork/exec of remote processes;
>   QEMU is still capable of fork/execing the remote processes unless its disabled
>   by seccomp.
>   When using libvirt, the daemon will spawn remote processes and pass the communication
>   file descriptors to main QEMU process and the remote processes.
>   The libvirt patches are in the making and will be sent out shortly;
> - using existing -device/-drive command line options to specify remote devices with
>   additional suboptons;
> - refractor message sending code;
> - remove specific HMP/QMP commands and use the one that exist now;
> - extend existing QMP commands;
> - added timeout to communication channel;
> 
> Following people contributed to this patchset:
> 
> John G Johnson <john.g.johnson@oracle.com>
> Jagannathan Raman <jag.raman@oracle.com>
> Elena Ufimtseva <elena.ufimtseva@oracle.com>
> Kanth Ghatraju <kanth.ghatraju@oracle.com>
> 
> For full concept writeup about QEMU disaggregation refer to
> docs/devel/qemu-multiprocess.txt.
> 
> This series has a limited scope and allows QEMU to launch
> LSI SCSI controller emulation in the separate process and
> execute HMP commands to manipulate the devices.
> This series with appropriate libvirt patches allows to
> launch a guest with remote processes using libvirt.
> (libvirt patches will be posted and will be reflected in the reply to
> this patch).
> 
> Please refer to the docs/qemu-multiprocess.txt for usage
> information.
> 
> his series is based on qemu upstream commit
> 3284aa128153750f14a61e8a96fd085e6f2999b6.
> 
> TODO items:
>   - bus support for remote process (non-default);
>   - live migration;
>   - performance improvements;
>   - support for more devices;
>   - support for seccomp for remote processes;
>   - support for CPU disaggregated emulation;
> 
> We would like to welcome all your ideas, concerns and questions
> for this patchset.

For future versions please make sure the mails sent a fully
threaded, so that all the patches are in-reply-to the cover
letter mail, rather than each scattered as a standalone mail.

The best way todo this is to use the excellent "git-publish"
tool. The added benefit of git-publish is that it will CC
all the subsystem maintainers whose code is touched

  https://github.com/stefanha/git-publish

It is packaged in Debian, Ubuntu, Fedora & EPEL

Regards,
Daniel
-- 
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