Re: [Qemu-devel] Reopen file descriptors on 'cont' command

[Christopher Pereira]

On 06-03-2015 14:19, Stefan Hajnoczi wrote:
> On Wed, Feb 25, 2015 at 09:32:18PM -0300, Christopher Pereira wrote:
> > Does qemu reopen files on a 'cont' command?
> >
> > When working with images on a gluster volume, file descriptors may get into
> > a bad state because of network timeouts, remounting a share, etc...and
> > reinitializing file descriptors may be usefull to get paused VMs up again.
> >
> > Related BZ:
> > https://bugzilla.redhat.com/show_bug.cgi?id=1058300
> No, QEMU doesn't reopen file descriptors.
>
> This can be challenging because QEMU supports file descriptor passing,
> which is used when the QEMU process is isolated using SELinux so it
> cannot open files itself.  Reopening would require new file descriptors
> passed in from the management tool.

Thanks Stefan.

I confirmed that libvirtd is not passing a FD to QEMU, but an image path.
Is QEMU reopening this image file when the VM is resumed?
QEMU must check if the FD (initialized by QEMU) is still valid, 
especially after resuming a paused VM.