DRM leases + X = SW only OpenGL acceleration on child X server

[Raimonds Cicans]

Hi!

I am playing with new "DRM leases" feature.
I am trying to implement single video card multi-seat.

Questions:

1) is HW accelerated OpenGL possible at all on child X server?

2) if answer for first question is "yes", then what can cause following
behaviour?

DISPLAY=:100 glxgears # Main X server. Works without problem

DISPLAY=:101 glxgears # Child X server. Get following errors
libGL error: failed to authenticate magic 1
libGL error: failed to load driver: radeonsi

All commands (X servers / glxgears) are run under root user.

Software versions:
Linux kernel: 4.16.12
libdrm: 2.4.93
xorg-server: 1.20.1
xf86-video-amdgpu: 18.1.0
mesa: 18.1.8



Raimonds Cicans
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[Michel Dänzer]

Post by Raimonds Cicans
Hi!
I am playing with new "DRM leases" feature.
I am trying to implement single video card multi-seat.
1) is HW accelerated OpenGL possible at all on child X server?
2) if answer for first question is "yes", then what can cause following
behaviour?
DISPLAY=:100 glxgears # Main X server. Works without problem
DISPLAY=:101 glxgears # Child X server. Get following errors
libGL error: failed to authenticate magic 1
libGL error: failed to load driver: radeonsi

Please attach both Xorg log files and the output of

LIBGL_DEBUG=verbose DISPLAY=:101 glxgears

[Raimonds Cicans]

Post by Michel Dänzer

Post by Raimonds Cicans
Hi!
I am playing with new "DRM leases" feature.
I am trying to implement single video card multi-seat.
1) is HW accelerated OpenGL possible at all on child X server?
2) if answer for first question is "yes", then what can cause following
behaviour?
DISPLAY=:100 glxgears # Main X server. Works without problem
DISPLAY=:101 glxgears # Child X server. Get following errors
libGL error: failed to authenticate magic 1
libGL error: failed to load driver: radeonsi

Please attach both Xorg log files and the output of
LIBGL_DEBUG=verbose DISPLAY=:101 glxgears

All files attached.



Raimonds Cicans

[Michel Dänzer]

Post by Raimonds Cicans

Post by Michel Dänzer

Post by Raimonds Cicans
Hi!
I am playing with new "DRM leases" feature.
I am trying to implement single video card multi-seat.
1) is HW accelerated OpenGL possible at all on child X server?
2) if answer for first question is "yes", then what can cause following
behaviour?
DISPLAY=:100 glxgears # Main X server. Works without problem
DISPLAY=:101 glxgears # Child X server. Get following errors
libGL error: failed to authenticate magic 1
libGL error: failed to load driver: radeonsi

Please attach both Xorg log files and the output of
LIBGL_DEBUG=verbose DISPLAY=:101 glxgears

All files attached.

Looks like drmAuthMagic returns an error for the leased FD in the Xorg
process.

Keith, was this working for you?

[Keith Packard]

Post by Michel Dänzer
Looks like drmAuthMagic returns an error for the leased FD in the Xorg
process.
Keith, was this working for you?

At one point, I'm nearly certain it was, but I haven't messed with this
in a while.

[Raimonds Cicans]

Post by Keith Packard

Post by Michel Dänzer
Looks like drmAuthMagic returns an error for the leased FD in the Xorg
process.
Keith, was this working for you?

At one point, I'm nearly certain it was, but I haven't messed with this
in a while.

Some questions:
1) Which video drivers support DRM leases? Only amdgpu?
2) Which video driver must load child X server? modesetting? Same as
master X server?


Raimonds Cicans


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[Keith Packard]

Post by Raimonds Cicans
1) Which video drivers support DRM leases? Only amdgpu?

Both amdgpu and modesetting.

Post by Raimonds Cicans
2) Which video driver must load child X server? modesetting? Same as
master X server?

Only modesetting appears to use xf86DRMMasterFd at this point; adding
that to amdgpu should be straightforward though.