I have a rtx 3070 and a 3090, I am absolutely sure I am binding vfio-pci to the 3090 and not the 3070.
I have bound the driver in two different ways, first by passing the IDs to the module and alternatively by manipulating the system interface and use the override (this is what I originally had to do when I used two 1080s, so I know it works). While the 3090 doesn't show a console, there's a remnant from the refund (and grub previously) there. The assessment Alex made previously, where aperture_remove_conflicting_pci_devices() is removing the driver (EFIFB) instead of the device seems correct, but it could also can be a quirky of how EFIFB is implemented. I recall reading a long time ago that EFIFB is a special device and once it detects changes it would simply give up. There was also no way to attach a device to it again as it depends on being preloaded outside the kernel; once something takes over the buffer reinitializing is "impossible". I never went deeper to try and understand it. On Mon, Dec 5, 2022, 2:00 AM Thomas Zimmermann <tzimmerm...@suse.de> wrote: > Hi > > Am 05.12.22 um 01:51 schrieb Alex Williamson: > > On Sat, 3 Dec 2022 17:12:38 -0700 > > "m...@lab.how" <m...@lab.how> wrote: > > > >> Hi, > >> > >> I hope it is ok to reply to this old thread. > > > > It is, but the only relic of the thread is the subject. For reference, > > the latest version of this posted is here: > > > > https://lore.kernel.org/all/20220622140134.12763-4-tzimmerm...@suse.de/ > > > > Which is committed as: > > > > d17378062079 ("vfio/pci: Remove console drivers") > > > >> Unfortunately, I found a > >> problem only now after upgrading to 6.0. > >> > >> My setup has multiple GPUs (2), and I depend on EFIFB to have a working > console. > > Which GPUs do you have? > > >> pre-patch behavior, when I bind the vfio-pci to my secondary GPU both > >> the passthrough and the EFIFB keep working fine. > >> post-patch behavior, when I bind the vfio-pci to the secondary GPU, > >> the EFIFB disappears from the system, binding the console to the > >> "dummy console". > > The efifb would likely use the first GPU. And vfio-pci should only > remove the generic driver from the second device. Are you sure that > you're not somehow using the first GPU with vfio-pci. > > >> Whenever you try to access the terminal, you have the screen stuck in > >> whatever was the last buffer content, which gives the impression of > >> "freezing," but I can still type. > >> Everything else works, including the passthrough. > > > > This sounds like the call to aperture_remove_conflicting_pci_devices() > > is removing the conflicting driver itself rather than removing the > > device from the driver. Is it not possible to unbind the GPU from > > efifb before binding the GPU to vfio-pci to effectively nullify the > > added call? > > > >> I can only think about a few options: > >> > >> - Is there a way to have EFIFB show up again? After all it looks like > >> the kernel has just abandoned it, but the buffer is still there. I > >> can't find a single message about the secondary card and EFIFB in > >> dmesg, but there's a message for the primary card and EFIFB. > >> - Can we have a boolean controlling the behavior of vfio-pci > >> altogether or at least controlling the behavior of vfio-pci for that > >> specific ID? I know there's already some option for vfio-pci and VGA > >> cards, would it be appropriate to attach this behavior to that option? > > > > I suppose we could have an opt-out module option on vfio-pci to skip > > the above call, but clearly it would be better if things worked by > > default. We cannot make full use of GPUs with vfio-pci if they're > > still in use by host console drivers. The intention was certainly to > > unbind the device from any low level drivers rather than disable use of > > a console driver entirely. DRM/GPU folks, is that possibly an > > interface we could implement? Thanks, > > When vfio-pci gives the GPU device to the guest, which driver driver is > bound to it? > > Best regards > Thomas > > > > > Alex > > > > -- > Thomas Zimmermann > Graphics Driver Developer > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5, 90409 Nürnberg, Germany > (HRB 36809, AG Nürnberg) > Geschäftsführer: Ivo Totev > >
