Kernel problem with multiseat on one card

Kernel problem with multiseat on one card

[Gert Vanhaerents]

Hi Kernel list,
I'm the IT person of a school, earlier we used multiseatcomputers for 
the school, i have maded with a XGL implementation and it works fine but 
not so fantastic. The school wants that i build new computers but the 
XGL project is too outdated so i can't use it anymore.

How can i make a multiseatcomputer with more then one user on one card 
with systemd? I have asked already to the makers of systemd but they 
said it's a kernel problem.

With Systemd loginctl and the nouveau drivers you have this:

─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
           │ [MASTER] drm:card0
           │ 
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
           │ │ [MASTER] drm:card0-DVI-D-1
           │ 
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
           │ │ [MASTER] drm:card0-HDMI-A-1
           │ 
└─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
           │   [MASTER] drm:card0-VGA-1
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
           │ drm:renderD128
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/graphics/fb0
           │ graphics:fb0 "nouveaudrmfb"

So it will be:

loginctl attach seat1 /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1

For the seat1 (the VGA d-sub output for seat1 and the other HDMI output 
for seat0) and of course the mouse and keyboard.

When you do this, all the graphics outputs are on the second seat 
(seat1) and not anymore on the first seat. So i need to move only the 
VGA output to seat1 and not all the outputs.


When i install the proprietary Nvidia drivers, i have the following:

[MASTER] pci:0000:08:00.0
           │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
           │ │ [MASTER] drm:card0
           │ 
└─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
           │   drm:renderD128

─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
           │ graphics:fb0 "EFI VGA"

So no VGA, DVI or HDMI items.

Linux is a very good multi-user system, so it is frustrating that it 
does not work. It does work under Windows without any problem, so it is 
certainly possible.Can you please check this or give me a tip somewhere 
so that I can continue looking for a solution? According to systemd this 
is a kernel problem, can you please solve this.


Hopefully someone can help, the children and school will always thank you!
Thanks in advance,
Gert

Kernel problem with multiseat on one card

[Gert Vanhaerents]

Hi Kernel list,

I'm the IT person of a school, earlier we used multiseatcomputers for 
the school, i have maded with a XGL implementation and it works fine but 
not so fantastic. The school wants that i build new computers but the 
XGL project is too outdated so i can't use it anymore.

How can i make a multiseatcomputer with more then one user on one card 
with systemd? I have asked already to the makers of systemd but they 
said it's a kernel problem.

With Systemd loginctl and the nouveau drivers you have this:

─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
           │ [MASTER] drm:card0
           │ 
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
           │ │ [MASTER] drm:card0-DVI-D-1
           │ 
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
           │ │ [MASTER] drm:card0-HDMI-A-1
           │ 
└─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
           │   [MASTER] drm:card0-VGA-1
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
           │ drm:renderD128
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/graphics/fb0
           │ graphics:fb0 "nouveaudrmfb"

So it will be:

loginctl attach seat1 
/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1

For the seat1 (the VGA d-sub output for seat1 and the other HDMI output 
for seat0) and of course the mouse and keyboard.

When you do this, all the graphics outputs are on the second seat 
(seat1) and not anymore on the first seat. So i need to move only the 
VGA output to seat1 and not all the outputs.


When i install the proprietary Nvidia drivers, i have the following:

[MASTER] pci:0000:08:00.0
           │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
           │ │ [MASTER] drm:card0
           │ 
└─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
           │   drm:renderD128

─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
           │ graphics:fb0 "EFI VGA"

So no VGA, DVI or HDMI items.

Linux is a very good multi-user system, so it is frustrating that it 
does not work. It does work under Windows without any problem, so it is 
certainly possible.Can you please check this or give me a tip somewhere 
so that I can continue looking for a solution? According to systemd this 
is a kernel problem, can you please solve this.


Hopefully someone can help, the children and school will always thank you!
Thanks in advance,
Gert

Re: Kernel problem with multiseat on one card

[Bagas Sanjaya]

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On Thu, Nov 30, 2023 at 11:48:24AM +0100, Gert Vanhaerents wrote:
> Hi Kernel list,
> I'm the IT person of a school, earlier we used multiseatcomputers for the
> school, i have maded with a XGL implementation and it works fine but not so
> fantastic. The school wants that i build new computers but the XGL project
> is too outdated so i can't use it anymore.
> 
> How can i make a multiseatcomputer with more then one user on one card with
> systemd? I have asked already to the makers of systemd but they said it's a
> kernel problem.
> 
> With Systemd loginctl and the nouveau drivers you have this:
> 
> ─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>           │ [MASTER] drm:card0
>           │
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
>           │ │ [MASTER] drm:card0-DVI-D-1
>           │
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
>           │ │ [MASTER] drm:card0-HDMI-A-1
>           │
> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>           │   [MASTER] drm:card0-VGA-1
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>           │ drm:renderD128
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/graphics/fb0
>           │ graphics:fb0 "nouveaudrmfb"
> 
> So it will be:
> 
> loginctl attach seat1 /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
> 
> For the seat1 (the VGA d-sub output for seat1 and the other HDMI output for
> seat0) and of course the mouse and keyboard.
> 
> When you do this, all the graphics outputs are on the second seat (seat1)
> and not anymore on the first seat. So i need to move only the VGA output to
> seat1 and not all the outputs.

Do you expect that GUI output is on both seats?

> 
> 
> When i install the proprietary Nvidia drivers, i have the following:
> 
> [MASTER] pci:0000:08:00.0
>           │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>           │ │ [MASTER] drm:card0
>           │
> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>           │   drm:renderD128
> 
> ─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
>           │ graphics:fb0 "EFI VGA"
> 
> So no VGA, DVI or HDMI items.

Then report to the GitHub tracker [1].

Thanks.

[1]: https://github.com/NVIDIA/open-gpu-kernel-modules/issues

-- 
An old man doll... just what I always wanted! - Clara

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Re: [Nouveau] Kernel problem with multiseat on one card

[Timur Tabi]

On Sat, 2023-12-02 at 20:18 +0700, Bagas Sanjaya wrote:
> 

> > When i install the proprietary Nvidia drivers, i have the following:
> > 
> > [MASTER] pci:0000:08:00.0
> >           │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
> >           │ │ [MASTER] drm:card0
> >           │
> > └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
> >           │   drm:renderD128
> > 
> > ─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
> >           │ graphics:fb0 "EFI VGA"
> > 
> > So no VGA, DVI or HDMI items.
> 
> Then report to the GitHub tracker [1].
> 
> Thanks.
> 
> [1]: https://github.com/NVIDIA/open-gpu-kernel-modules/issues
> 

No, do NOT report this on the Github tracker!

That github tracker is ONLY for bugs that occur with OpenRM (the "Open GPU
Kernel Module") but not with the the proprietary driver.  If you have a bug
with the the Nvidia proprietary driver, that must be reported on the Nvidia
forum instead: 

https://forums.developer.nvidia.com/c/gpu-graphics/linux/148

Re: [Nouveau] Kernel problem with multiseat on one card

[Bagas Sanjaya]

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On Sat, Dec 02, 2023 at 03:28:25PM +0000, Timur Tabi wrote:
> On Sat, 2023-12-02 at 20:18 +0700, Bagas Sanjaya wrote:
> > 
> 
> > > When i install the proprietary Nvidia drivers, i have the following:
> > > 
> > > [MASTER] pci:0000:08:00.0
> > >           │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
> > >           │ │ [MASTER] drm:card0
> > >           │
> > > └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
> > >           │   drm:renderD128
> > > 
> > > ─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
> > >           │ graphics:fb0 "EFI VGA"
> > > 
> > > So no VGA, DVI or HDMI items.
> > 
> > Then report to the GitHub tracker [1].
> > 
> > Thanks.
> > 
> > [1]: https://github.com/NVIDIA/open-gpu-kernel-modules/issues
> > 
> 
> No, do NOT report this on the Github tracker!
> 
> That github tracker is ONLY for bugs that occur with OpenRM (the "Open GPU
> Kernel Module") but not with the the proprietary driver.  If you have a bug
> with the the Nvidia proprietary driver, that must be reported on the Nvidia
> forum instead: 
> 
> https://forums.developer.nvidia.com/c/gpu-graphics/linux/148
> 

Thanks for the correct pointer!

Sorry for inconvenience.

-- 
An old man doll... just what I always wanted! - Clara

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Re: Kernel problem with multiseat on one card

[Gert Vanhaerents]

Op 2/12/2023 om 14:18 schreef Bagas Sanjaya:
> On Thu, Nov 30, 2023 at 11:48:24AM +0100, Gert Vanhaerents wrote:
>> Hi Kernel list,
>> I'm the IT person of a school, earlier we used multiseatcomputers for the
>> school, i have maded with a XGL implementation and it works fine but not so
>> fantastic. The school wants that i build new computers but the XGL project
>> is too outdated so i can't use it anymore.
>>
>> How can i make a multiseatcomputer with more then one user on one card with
>> systemd? I have asked already to the makers of systemd but they said it's a
>> kernel problem.
>>
>> With Systemd loginctl and the nouveau drivers you have this:
>>
>> ─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>>            │ [MASTER] drm:card0
>>            │
>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
>>            │ │ [MASTER] drm:card0-DVI-D-1
>>            │
>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
>>            │ │ [MASTER] drm:card0-HDMI-A-1
>>            │
>> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>>            │   [MASTER] drm:card0-VGA-1
>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>>            │ drm:renderD128
>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/graphics/fb0
>>            │ graphics:fb0 "nouveaudrmfb"
>>
>> So it will be:
>>
>> loginctl attach seat1 /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>>
>> For the seat1 (the VGA d-sub output for seat1 and the other HDMI output for
>> seat0) and of course the mouse and keyboard.
>>
>> When you do this, all the graphics outputs are on the second seat (seat1)
>> and not anymore on the first seat. So i need to move only the VGA output to
>> seat1 and not all the outputs.
> Do you expect that GUI output is on both seats?

I want the result that i have one seat (seat0) on the VGA/D-sub output 
of the graphic card

a second seat (seat1) on the HDMI output of the graphic card

and a third seat (seat2) on the DVI output of the graphic card

In theory it should work with the following:
loginctl attach seat1 
/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1

loginctl attach seat2 
/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1

But when i do this all the outputs will be used on seat2 (because they 
do all the outputs automaticly to the latest attached seat)


>>
>> When i install the proprietary Nvidia drivers, i have the following:
>>
>> [MASTER] pci:0000:08:00.0
>>            │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>>            │ │ [MASTER] drm:card0
>>            │
>> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>>            │   drm:renderD128
>>
>> ─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
>>            │ graphics:fb0 "EFI VGA"
>>
>> So no VGA, DVI or HDMI items.
> Then report to the GitHub tracker [1].
>
> Thanks.
>
> [1]: https://github.com/NVIDIA/open-gpu-kernel-modules/issues
>

Re: Kernel problem with multiseat on one card

[Gert Vanhaerents]

>>> Hi Kernel list,
>>> I'm the IT person of a school, earlier we used multiseatcomputers 
>>> for the
>>> school, i have maded with a XGL implementation and it works fine but 
>>> not so
>>> fantastic. The school wants that i build new computers but the XGL 
>>> project
>>> is too outdated so i can't use it anymore.
>>>
>>> How can i make a multiseatcomputer with more then one user on one 
>>> card with
>>> systemd? I have asked already to the makers of systemd but they said 
>>> it's a
>>> kernel problem.
>>>
>>> With Systemd loginctl and the nouveau drivers you have this:
>>>
>>> ─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>>>            │ [MASTER] drm:card0
>>>            │
>>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1 
>>>
>>>            │ │ [MASTER] drm:card0-DVI-D-1
>>>            │
>>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1 
>>>
>>>            │ │ [MASTER] drm:card0-HDMI-A-1
>>>            │
>>> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1 
>>>
>>>            │   [MASTER] drm:card0-VGA-1
>>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>>>            │ drm:renderD128
>>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/graphics/fb0
>>>            │ graphics:fb0 "nouveaudrmfb"
>>>
>>> So it will be:
>>>
>>> loginctl attach seat1 
>>> /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>>>
>>> For the seat1 (the VGA d-sub output for seat1 and the other HDMI 
>>> output for
>>> seat0) and of course the mouse and keyboard.
>>>
>>> When you do this, all the graphics outputs are on the second seat 
>>> (seat1)
>>> and not anymore on the first seat. So i need to move only the VGA 
>>> output to
>>> seat1 and not all the outputs.
>> Do you expect that GUI output is on both seats?
>
> I want the result that i have one seat (seat0) on the VGA/D-sub output 
> of the graphic card
>
> a second seat (seat1) on the HDMI output of the graphic card
>
> and a third seat (seat2) on the DVI output of the graphic card
>
> In theory it should work with the following:
> loginctl attach seat1 
> /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
>
> loginctl attach seat2 
> /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
>
> But when i do this all the outputs will be used on seat2 (because they 
> do all the outputs automaticly to the latest attached seat)
>
>
>>>
>>> When i install the proprietary Nvidia drivers, i have the following:
>>>
>>> [MASTER] pci:0000:08:00.0
>>>            │ 
>>> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>>>            │ │ [MASTER] drm:card0
>>>            │
>>> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>>>            │   drm:renderD128
>>>
>>> ─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
>>>            │ graphics:fb0 "EFI VGA"
>>>
>>> So no VGA, DVI or HDMI items.
>> Then report to the GitHub tracker [1].
>>
>> Thanks.
>>
>> [1]: https://github.com/NVIDIA/open-gpu-kernel-modules/issues
>>

Re: [Nouveau] Kernel problem with multiseat on one card

[Gert Vanhaerents]

>>>>> When i install the proprietary Nvidia drivers, i have the following:
>>>>>
>>>>> [MASTER] pci:0000:08:00.0
>>>>>            │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>>>>>            │ │ [MASTER] drm:card0
>>>>>            │
>>>>> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/renderD128
>>>>>            │   drm:renderD128
>>>>>
>>>>> ─/sys/devices/platform/efi-framebuffer.0/graphics/fb0
>>>>>            │ graphics:fb0 "EFI VGA"
>>>>>
>>>>> So no VGA, DVI or HDMI items.
>>>> Then report to the GitHub tracker [1].
>>>>
>>>> Thanks.
>>>>
>>>> [1]:https://github.com/NVIDIA/open-gpu-kernel-modules/issues
>>>>
>>> No, do NOT report this on the Github tracker!
>>>
>>> That github tracker is ONLY for bugs that occur with OpenRM (the "Open GPU
>>> Kernel Module") but not with the the proprietary driver.  If you have a bug
>>> with the the Nvidia proprietary driver, that must be reported on the Nvidia
>>> forum instead:
>>>
>>> https://forums.developer.nvidia.com/c/gpu-graphics/linux/148
>>
>> OK  i will report it to nvidia. But with the nouveau drivers it's 
>> also not working. Are you sure it's not a kernel problem?
>>
>> Because according to systemd it would be a kernel problem.  
>> (personaly i am also thinking it's a driver problem)
>>

Re: [Nouveau] Kernel problem with multiseat on one card

[Timur Tabi]

On Mon, 2023-12-04 at 09:51 +0100, Gert Vanhaerents wrote:
> OK  i will report it to nvidia. But with the nouveau drivers it's also not
> working. Are you sure it's not a kernel problem? 
> Because according to systemd it would be a kernel problem.  (personaly i am
> also thinking it's a driver problem)

Unfortunately, it's not easy for Nouveau to debug problems with GSP-RM. 
However, if the problem exists in the proprietary driver, then Nvidia could
fix it.  That would then lead to a new version of OpenRM that Nouveau could
use.

Re: [Nouveau] Kernel problem with multiseat on one card - Wil be more than one window manager on one card

[Gert Vanhaerents]

Op 4/12/2023 om 15:11 schreef Timur Tabi:
> On Mon, 2023-12-04 at 09:51 +0100, Gert Vanhaerents wrote:
>> OK  i will report it to nvidia. But with the nouveau drivers it's also not
>> working. Are you sure it's not a kernel problem?
>> Because according to systemd it would be a kernel problem.  (personaly i am
>> also thinking it's a driver problem)
> Unfortunately, it's not easy for Nouveau to debug problems with GSP-RM.
> However, if the problem exists in the proprietary driver, then Nvidia could
> fix it.  That would then lead to a new version of OpenRM that Nouveau could
> use.

I have contacted Nvidia and now i can see the outputs such like this:

─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
           │ [MASTER] drm:card0
           │ 
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
           │ │ [MASTER] drm:card0-DVI-D-1
           │ 
├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
           │ │ [MASTER] drm:card0-HDMI-A-1
           │ 
└─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
           │   [MASTER] drm:card0-VGA-1

But the problem is now the same of with the Nouveau driver. When you do 
this:

loginctl attach seat1 
/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1

For the seat1 (the VGA d-sub output for seat1 and the other HDMI output 
for seat0) and of course the mouse and keyboard.

When you do this, all the graphics outputs are on the second seat 
(seat1) and not anymore on the first seat. So i need to move only the 
VGA output to seat1 and not all the outputs.


The problem is that linux can not start 2 or more window managers on one 
card (even if you don't need a multiseat, but use only one mouse and 
keyboard).

So how can i fix that i can use more than one window manager on one 
physical graphics card? (without Xephyr or something because they are to 
outdated and works not good).

I have tried with: Linux Mint, Ubuntu and Debian all the same problem.

Re: [Nouveau] Kernel problem with multiseat on one card - Wil be more than one window manager on one card

[Gert Vanhaerents]

In the meantime I have contacted everyone who could have something to do 
with it:
Kernel groups
System D
Nvidia

And gues: Everyone says it's not their fault.

But we don't give up. Linux is such a beautiful and solid system. Why 
would it work with Windows and not Linux?

Our analysis has now discovered that the problem does indeed come from 
the kernel. The kernel does not allow several users to access a graphics 
card at the same time.Indeed, to use it, several users need access to 
the graphics card at the same time.
Can this simultaneous access be allowed by the kernel after all?
Or can the kernel be adjusted so that this would be possible?


Op 15/12/2023 om 10:59 schreef Gert Vanhaerents:
>
> Op 4/12/2023 om 15:11 schreef Timur Tabi:
>> On Mon, 2023-12-04 at 09:51 +0100, Gert Vanhaerents wrote:
>>> OK  i will report it to nvidia. But with the nouveau drivers it's 
>>> also not
>>> working. Are you sure it's not a kernel problem?
>>> Because according to systemd it would be a kernel problem. 
>>> (personaly i am
>>> also thinking it's a driver problem)
>> Unfortunately, it's not easy for Nouveau to debug problems with GSP-RM.
>> However, if the problem exists in the proprietary driver, then Nvidia 
>> could
>> fix it.  That would then lead to a new version of OpenRM that Nouveau 
>> could
>> use.
>
> I have contacted Nvidia and now i can see the outputs such like this:
>
> ─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>           │ [MASTER] drm:card0
>           │ 
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
>           │ │ [MASTER] drm:card0-DVI-D-1
>           │ 
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
>           │ │ [MASTER] drm:card0-HDMI-A-1
>           │ 
> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>           │   [MASTER] drm:card0-VGA-1
>
> But the problem is now the same of with the Nouveau driver. When you 
> do this:
>
> loginctl attach seat1 
> /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>
> For the seat1 (the VGA d-sub output for seat1 and the other HDMI 
> output for seat0) and of course the mouse and keyboard.
>
> When you do this, all the graphics outputs are on the second seat 
> (seat1) and not anymore on the first seat. So i need to move only the 
> VGA output to seat1 and not all the outputs.
>
>
> The problem is that linux can not start 2 or more window managers on 
> one card (even if you don't need a multiseat, but use only one mouse 
> and keyboard).
>
> So how can i fix that i can use more than one window manager on one 
> physical graphics card? (without Xephyr or something because they are 
> to outdated and works not good).
>
> I have tried with: Linux Mint, Ubuntu and Debian all the same problem.
>
>
>

Re: Kernel problem with multiseat on one card - more than 1 user simultaneously on 1 video card

[Gert Vanhaerents]

In the meantime I have contacted everyone who could have something to do 
with it:
Kernel groups
System D
Nvidia
And gues:  Everyone says it's not their fault.

But we don't give up. Linux is such a beautiful and solid system. Why 
would it work with Windows and not Linux?

Our analysis has now discovered that the problem does indeed come from 
the kernel. The kernel does not allow several users to access a graphics 
card at the same time. Indeed, to use it, several users need access to 
the graphics card at the same time.

Can this simultaneous access be allowed by the kernel after all?
Or can the kernel be adjusted so that this would be possible?




Op 15/12/2023 om 10:59 schreef Gert Vanhaerents:
>
> Op 4/12/2023 om 15:11 schreef Timur Tabi:
>> On Mon, 2023-12-04 at 09:51 +0100, Gert Vanhaerents wrote:
>>> OK  i will report it to nvidia. But with the nouveau drivers it's 
>>> also not
>>> working. Are you sure it's not a kernel problem?
>>> Because according to systemd it would be a kernel problem. 
>>> (personaly i am
>>> also thinking it's a driver problem)
>> Unfortunately, it's not easy for Nouveau to debug problems with GSP-RM.
>> However, if the problem exists in the proprietary driver, then Nvidia 
>> could
>> fix it.  That would then lead to a new version of OpenRM that Nouveau 
>> could
>> use.
>
> I have contacted Nvidia and now i can see the outputs such like this:
>
> ─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>           │ [MASTER] drm:card0
>           │ 
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
>           │ │ [MASTER] drm:card0-DVI-D-1
>           │ 
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
>           │ │ [MASTER] drm:card0-HDMI-A-1
>           │ 
> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>           │   [MASTER] drm:card0-VGA-1
>
> But the problem is now the same of with the Nouveau driver. When you 
> do this:
>
> loginctl attach seat1 
> /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>
> For the seat1 (the VGA d-sub output for seat1 and the other HDMI 
> output for seat0) and of course the mouse and keyboard.
>
> When you do this, all the graphics outputs are on the second seat 
> (seat1) and not anymore on the first seat. So i need to move only the 
> VGA output to seat1 and not all the outputs.
>
>
> The problem is that linux can not start 2 or more window managers on 
> one card (even if you don't need a multiseat, but use only one mouse 
> and keyboard).
>
> So how can i fix that i can use more than one window manager on one 
> physical graphics card? (without Xephyr or something because they are 
> to outdated and works not good).
>
> I have tried with: Linux Mint, Ubuntu and Debian all the same problem.
>
>

Re: Kernel problem with multiseat on one card - more than 1 user simultaneously on 1 video card

[Gert Vanhaerents]

In the meantime I have contacted everyone who could have something to do 
with it:
Kernel groups
System D
Nvidia
And gues:  Everyone says it's not their fault.

But we don't give up. Linux is such a beautiful and solid system. Why 
would it work with Windows and not Linux?

Our analysis has now discovered that the problem does indeed come from 
the kernel. The kernel does not allow several users to access a graphics 
card at the same time. Indeed, to use it, several users need access to 
the graphics card at the same time.

Can this simultaneous access be allowed by the kernel after all?
Or can the kernel be adjusted so that this would be possible?

In the meantime I am also working with a multiseat company to search 
together for a solution for multiseat under Linux. This company is 
working on creating an easy and user-friendly program to work via a 
multiseat with Linux, and they have already a high-selling multiseat 
program for Windows. The intention would be to create a program that 
works like some multiseat programs in Windows: install, drag mice and 
keyboards to the right screen, restart and it works as multiseat.
But such a program is only interesting if it can work for different 
users on 1 video card. For example, for a multiseat of 6 users you need 
3 video cards with 2 outputs each.
For now the programmers has a good béta program, but with the 
restriction only one workstation on one video card, but then it's not 
interesting at all.


Op 15/12/2023 om 10:59 schreef Gert Vanhaerents:
>
> Op 4/12/2023 om 15:11 schreef Timur Tabi:
>> On Mon, 2023-12-04 at 09:51 +0100, Gert Vanhaerents wrote:
>>> OK  i will report it to nvidia. But with the nouveau drivers it's 
>>> also not
>>> working. Are you sure it's not a kernel problem?
>>> Because according to systemd it would be a kernel problem. 
>>> (personaly i am
>>> also thinking it's a driver problem)
>> Unfortunately, it's not easy for Nouveau to debug problems with GSP-RM.
>> However, if the problem exists in the proprietary driver, then Nvidia 
>> could
>> fix it.  That would then lead to a new version of OpenRM that Nouveau 
>> could
>> use.
>
> I have contacted Nvidia and now i can see the outputs such like this:
>
> ─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0
>           │ [MASTER] drm:card0
>           │ 
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-DVI-D-1
>           │ │ [MASTER] drm:card0-DVI-D-1
>           │ 
> ├─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-HDMI-A-1
>           │ │ [MASTER] drm:card0-HDMI-A-1
>           │ 
> └─/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>           │   [MASTER] drm:card0-VGA-1
>
> But the problem is now the same of with the Nouveau driver. When you 
> do this:
>
> loginctl attach seat1 
> /sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/drm/card0/card0-VGA-1
>
> For the seat1 (the VGA d-sub output for seat1 and the other HDMI 
> output for seat0) and of course the mouse and keyboard.
>
> When you do this, all the graphics outputs are on the second seat 
> (seat1) and not anymore on the first seat. So i need to move only the 
> VGA output to seat1 and not all the outputs.
>
>
> The problem is that linux can not start 2 or more window managers on 
> one card (even if you don't need a multiseat, but use only one mouse 
> and keyboard).
>
> So how can i fix that i can use more than one window manager on one 
> physical graphics card? (without Xephyr or something because they are 
> to outdated and works not good).
>
> I have tried with: Linux Mint, Ubuntu and Debian all the same problem.
>
>