Since QEMU always picks the default DRI device, libvirt doesn't know which one
to put into the mount namespace and relabel it accordingly, hence hitting
permission issues, unless admin tweaks the default permissions of the DRI
devices.

https://bugzilla.redhat.com/show_bug.cgi?id=1648236

Erik Skultety (3):
  qapi: Add "rendernode" display option for egl-headless
  ui: Allow specifying 'rendernode' display option for egl-headless
  help: Provide help for egl-headless

 qapi/ui.json      | 16 +++++++++++++++-
 qemu-options.hx   |  6 +++++-
 ui/egl-headless.c |  2 +-
 3 files changed, 21 insertions(+), 3 deletions(-)

--
2.19.1

On 11/15/18 9:15 AM, Erik Skultety wrote:
> Since QEMU always picks the default DRI device, libvirt doesn't know which one
> to put into the mount namespace and relabel it accordingly, hence hitting
> permission issues, unless admin tweaks the default permissions of the DRI
> devices.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1648236

This is borderline between fixing a bug that gets in the way of libvirt 
(and thus useful for 3.1) and a feature (thus for 4.0, since we won't 
have a 3.2 release). I'll let Gerd decide.

> 
> Erik Skultety (3):
>    qapi: Add "rendernode" display option for egl-headless
>    ui: Allow specifying 'rendernode' display option for egl-headless
>    help: Provide help for egl-headless
> 
>   qapi/ui.json      | 16 +++++++++++++++-
>   qemu-options.hx   |  6 +++++-
>   ui/egl-headless.c |  2 +-
>   3 files changed, 21 insertions(+), 3 deletions(-)
> 
> --
> 2.19.1
> 
> 
> 

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

On Thu, Nov 15, 2018 at 09:47:44AM -0600, Eric Blake wrote:
> On 11/15/18 9:15 AM, Erik Skultety wrote:
> > Since QEMU always picks the default DRI device, libvirt doesn't know which one
> > to put into the mount namespace and relabel it accordingly, hence hitting
> > permission issues, unless admin tweaks the default permissions of the DRI
> > devices.
> > 
> > https://bugzilla.redhat.com/show_bug.cgi?id=1648236
> 
> This is borderline between fixing a bug that gets in the way of libvirt (and
> thus useful for 3.1) and a feature (thus for 4.0, since we won't have a 3.2
> release). I'll let Gerd decide.

It's simple enough and we are early in the -rc cycle still, I think it
would be okay for 3.1.

cheers,
  Gerd

On Fri, Nov 16, 2018 at 09:43:52AM +0100, Gerd Hoffmann wrote:
> On Thu, Nov 15, 2018 at 09:47:44AM -0600, Eric Blake wrote:
> > On 11/15/18 9:15 AM, Erik Skultety wrote:
> > > Since QEMU always picks the default DRI device, libvirt doesn't know which one
> > > to put into the mount namespace and relabel it accordingly, hence hitting
> > > permission issues, unless admin tweaks the default permissions of the DRI
> > > devices.
> > >
> > > https://bugzilla.redhat.com/show_bug.cgi?id=1648236
> >
> > This is borderline between fixing a bug that gets in the way of libvirt (and
> > thus useful for 3.1) and a feature (thus for 4.0, since we won't have a 3.2
> > release). I'll let Gerd decide.
>
> It's simple enough and we are early in the -rc cycle still, I think it
> would be okay for 3.1.

As far as upstream's concerned, I'm okay with both because libvirt has to add
another version specific capability enum for this anyway. It's been broken
since libvirt 4.6.0 where I added egl-headless graphics type. Luckily, even
though it's far from optimal, a working solution exists, just change the
permissions on the device.

Thanks,
Erik

On Fri, Nov 16, 2018 at 10:24:30AM +0100, Erik Skultety wrote:
> On Fri, Nov 16, 2018 at 09:43:52AM +0100, Gerd Hoffmann wrote:
> > It's simple enough and we are early in the -rc cycle still, I think it
> > would be okay for 3.1.
> 
> As far as upstream's concerned, I'm okay with both because libvirt has to add
> another version specific capability enum for this anyway. It's been broken
> since libvirt 4.6.0 where I added egl-headless graphics type. Luckily, even
> though it's far from optimal, a working solution exists, just change the
> permissions on the device.

I'm fine either way too.  So just pick a version, update the doc
comments and repost.

thanks,
  Gerd