Re: [Qemu-devel] [PATCH v9 0/6] monitor: enable OOB by default

[Eric Blake]

On 10/10/18 7:05 PM, Peter Xu wrote:

> > other than the command line that is hanging:
> >
> > /home/eblake/qemu/x86_64-softmmu/qemu-system-x86_64 -S -no-user-config
> > -nodefaults -nographic -machine none,accel=kvm:tcg -qmp
> > unix:/var/lib/libvirt/qemu/capabilities.monitor.sock,server,nowait -pidfile
> > /var/lib/libvirt/qemu/capabilities.pidfile -daemonize
> >
> > And I suspect it is the -daemonize that is causing the hang I'm seeing when
> > run by libvirt.

> It's very possible the daemonize thing, actually Wolfgang Bumiller has
> posted patches to fix this up (it's not the problem of this series,
> but it just exposed this to libvirt by the series since it only
> happens when oob and daemonize are both enabled).  The fixes are:
>
>    [PATCH v2 0/2] delay monitor iothread creation
>
> Since it cannot be applied cleanly onto this series, I resolved the
> conflicts and pushed a tree here in case you wanna try with these two
> extra patches applied:
>
>    https://github.com/xzpeter/qemu/tree/test-oob

Technically, we should apply the patches in the opposite order 
(Wolfgang's first, then yours), so that bisection does not land on a 
known-bad hang situation.

> Please feel free to test with libvirt again with that.
>
> Thanks for playing with the tree and further investigation!  I will
> also mention this in the next version of cover letter (if there is one).

Confirmed that libvirt no longer hung with Wolfgang's patches added in.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org