[vfio-users] Problems passing through Creative X-Fi PCIe sound card

[Michael Slade]

Adding nointxmask=1 worked!  With no issues at all.  I think because all 
the devices are getting their own interrupts (on the host) anyway.

So do you want me to try to add the card to quirks.c?  I could probably 
manage it, just I haven't compiled a kernel in ~50 years.

Alex Williamson wrote:
> I'd guess the device probes OK for DisINTx support, but it doesn't
> actually work, the interrupt continues to fire but vfio-pci says "not
> my interrupt, my device is masked", when actually it is.  There's a
> vfio-pci module option, nointxmask=1 you can use to disable this PCI
> 2.3 required feature and mask at the IOAPIC instead.  The difficulty is
> that vfio needs to be able to get an exclusive interrupt for the
> device when using IOAPIC masking, which might mean you need to unbind
> anything sharing the interrupt in the host.  The extra bummer is that
> it's a global option, so you'll need to do the same for all other
> assigned devices.  If it works, we can specifically blacklist the device
> in the kernel (drivers/pci/quirks.c) using the quirk_broken_intx_masking
> function in the fixup so that the vfio-pci module option is not
> required and you'll only need to make sure the audio card has an
> exclusive interrupt. TL;DR, the device probes ok for an interrupt
> masking feature it doesn't support and interrupts for the card die.
> Thanks,