Messages in this thread | | | Date | Mon, 5 Dec 2022 11:11:17 +0100 | Subject | Re: [PATCH 2/2] vfio/pci: Remove console drivers | From | Thomas Zimmermann <> |
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Hi
Am 05.12.22 um 10:32 schrieb mb@lab.how: > 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.
We recently reworked fbdev's interaction with the aperture helpers. [1] All devices should now be removed iff the driver has been bound to it (which should be the case here) The patches went into an v6.1-rc.
Could you try the most recent v6.1-rc and report if this fixes the problem?
Best regards Thomas
[1] https://patchwork.freedesktop.org/series/106040/
> > > On Mon, Dec 5, 2022, 2:00 AM Thomas Zimmermann <tzimmermann@suse.de > <mailto:tzimmermann@suse.de>> wrote: > > Hi > > Am 05.12.22 um 01:51 schrieb Alex Williamson: > > On Sat, 3 Dec 2022 17:12:38 -0700 > > "mb@lab.how" <mb@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-tzimmermann@suse.de/ <https://lore.kernel.org/all/20220622140134.12763-4-tzimmermann@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 >
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev [unhandled content-type:application/pgp-signature] | |