On 6/27/25 08:38, Corvin Köhne wrote:
On Thu, 2025-06-26 at 16:49 +0200, Stephan Althaus wrote:
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
FYI, I'm working on a desktop system with an RTX A500 on 15.0-CURRENT.
Ubuntu dmesg reports "NVRM: Can't find an IRQ for your NVIDIA card!" by default.
Setting the INTPIN register solve this issue and the card can be detected by the
nvidia-smi command. However, as mentioned in my initial post, I'm not sure what
has to be emulated to be able to set the INTPIN in a sane way.
Hi!
I am sorry, i have no knowledge on that topic, how that works in detail.
What i can say from my recent tests on various hosts/guests, with my
GT1030, that the GPU mostly has INT_PIN 0x01, and the audio device
always INT_PIN 0x02.
I can't say for sure if it is 'always' because i don't think i have log
files for each combination :-/
00:08.0 VGA compatible controller: NVIDIA Corporation GP108 [GeForce GT
1030] (rev a1) (prog-if 00 [VGA controller])
Subsystem: Micro-Star International Co., Ltd. [MSI] Device 8c98
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B- DisINTx+
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin A routed to IRQ 45
00:08.1 Audio device: NVIDIA Corporation GP108 High Definition Audio
Controller (rev a1)
Subsystem: Micro-Star International Co., Ltd. [MSI] Device 8c98
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx+
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin B routed to IRQ 22
With the AMD RX 6400 there is the same pattern: PIN A to the GPU, PIN B
to the audio device..
I am not shure where the INT_PIN gets set/mapped, in the bhyve command
or by the BHYVE_UEFI BIOS, or by the guest OS (?)
If you need some special info, i will happily assist and startup my BSD
host and see...
Regards,
Stephan
