[Libva] [PATCH] drm: remove va_drm_is_authenticated check

[Sean V Kelley]

On Thu, 2016-11-17 at 18:17 +0000, Xiang, Haihao wrote:
> > -----Original Message-----
> > From: Sean V Kelley [mailto:seanvk at posteo.de]
> > Sent: Friday, November 18, 2016 12:47 AM
> > To: Emil Velikov <emil.l.velikov at gmail.com>; Xiang, Haihao
> > <haihao.xiang at intel.com>
> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>; libva at lists.freedesktop
> > .org; David
> > Herrmann <dh.herrmann at gmail.com>
> > Subject: Re: [Libva] [PATCH] drm: remove va_drm_is_authenticated
> > check
> > 
> > On Thu, 2016-11-17 at 16:42 +0000, Emil Velikov wrote:
> > > On 17 November 2016 at 15:38, Xiang, Haihao <haihao.xiang at intel.c
> > > om>
> > > wrote:
> > > > > From: Libva [mailto:libva-bounces at lists.freedesktop.org] On
> > > > > Behalf
> > > > > Of Emil Velikov
> > > > > Sent: Tuesday, November 15, 2016 11:24 PM
> > > > > To: libva at lists.freedesktop.org
> > > > > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>; David Herrmann
> > > > > <dh.herrmann at gmail.com>
> > > > > Subject: [Libva] [PATCH] drm: remove va_drm_is_authenticated
> > > > > check
> > > > > 
> > > > > If we do not use a render node we must authenticate.
> > > > 
> > > > It is not true.  A root or master user can access
> > > > /dev/dri/card0
> > > > without authentication in drm.
> > > > va_drm_is_authenticated() is used to check for this cases.
> > > > 
> > > 
> > > Surely you're not suggesting that running your video player as
> > > root is
> > > a wise idea ;-)
> > 
> > Agreed.
> 
> I also agree we should run video player as a normal user, however
> some customer prefers root.
> 
> > 
> > > 
> > > Regardless, there's something _really_ fishy with libva if it
> > > needs
> > > va_drm_is_authenticated.
> > > Any other software out there does not need to (or do so) - some
> > > examples include Xorg, Wayland and other Weston compositors,
> > > Mesa, IGT
> > > (a ton of GPU tests) ... be that as root, user or otherwise.
> > 
> > 
> > We don't need it, in my opinion.
> 
> We can still run VAAPI application as root to access /dev/dri/card0
> with this patch, but cannot
> run 2+ VAAPI applications at the same time.  We can suggest customer
> to use render node first because
> authentication isn't needed for render node.
> 
> I am fine to apply the patch.

Good.  I'm glad we are aligned. 

Thanks,

Sean

> 
> > 
> > Sean
> > 
> > > 
> > > Emil
> > > _______________________________________________
> > > Libva mailing list
> > > Libva at lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/libva
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