Re: bhyve: GPU passthrough for Nvidia cards

From: Stephan Althaus <Stephan.Althaus_at_Duedinghausen.eu>
Date: Fri, 27 Jun 2025 06:31:36 UTC
On 6/27/25 08:00, Stephan Althaus wrote:
> On 6/26/25 23:47, Nuno Teixeira wrote:
>> Hello Stephan,
>>
>> A year a go I did try passtrhu a dedicated nvidia GTX 1650 while 
>> using integrated intel graphics (laptop Lenovo Legion 5 15IMH05). 
>> Windows detected card but nvidia drivers install failed at some point.
>> On this laptop I did setup bios to use integrated graphics so I can 
>> passthru dedicated nvidia.
>>
>> Think I will give a new try since I follow main.
>>
>> Are you using laptops for this usecase?
>>
>> Thanks!
>>
>> Stephan Althaus <Stephan.Althaus@duedinghausen.eu> escreveu (quinta, 
>> 26/06/2025 à(s) 15:50):
>>
>>     On 6/26/25 15:07, Corvin Köhne wrote:
>>     > Hi,
>>     >
>>     > I'm currently experimenting with GPU passthrough for Nvidia
>>     cards. All I have to
>>     > do to make it work with Ubuntu guests, is setting the INTPIN
>>     register to any
>>     > value instead of just 0x00. Unfortunately, I'm unfamiliar with
>>     PCI legacy
>>     > interrupts and how they work. The INTLINE register is set to
>>     0xFF (unconnected).
>>     > So, is it safe to set the INTPIN register or what has to be
>>     done for it to work
>>     > as expected?
>>     >
>>     > Any help would be appreciated.
>>     >
>>     >
>>     Hi!
>>
>>     You surely mean 'newer' NVidia cards, as my GT1030 works with
>>     FreeBSD
>>     14.2 Host and ubuntu guest, NVIdia driver 570, (and Win guest btw)
>>     out-of-the-box, no kernel/driver modding...
>>
>>     Regards,
>>
>>     Stephan
>>
>>
>>
>>
>>
>> -- 
>> Nuno Teixeira
>> FreeBSD UNIX: <eduardo@FreeBSD.org>  Web: https://FreeBSD.org 
>> <https://FreeBSD.org>
>
> Hello!
>
> Oh, laptops... With this "Optimus"-called feature i am not shure if it 
> will work...
>
> But i think it's worth trying.
>
> Maybe you will need the GPU ROM. 
> (https://forums.FreeBSD.org/threads/current-state-of-bhyve-nvidia-passthrough.88244/post-706455)
>
> Good luck!
>
> Stephan
>
>
Hi!

Whilst trying to get it to work, i would suggest to always shut the host 
down, not only restart the guest/vm, to be on the safe side.

There may be side effects regarding the initialization of the GPU..

When you have a working setup, this may change and you may can reboot 
the vm and have always a working GPU, maybe..

Regards,

Stephan