On Wed, Jun 28, 2023 at 12:56:40AM +0000, Liu, Yi L wrote: > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Sent: Wednesday, June 28, 2023 12:12 AM > > > > On Tue, Jun 27, 2023 at 08:54:33AM +0000, Liu, Yi L wrote: > > > > From: Alex Williamson <alex.williamson@xxxxxxxxxx> > > > > Sent: Thursday, June 22, 2023 5:54 AM > > > > > > > > On Fri, 16 Jun 2023 02:39:46 -0700 > > > > Yi Liu <yi.l.liu@xxxxxxxxx> wrote: > > > > > > > > +VFIO device cdev doesn't rely on VFIO group/container/iommu drivers. > > > > > +Hence those modules can be fully compiled out in an environment > > > > > +where no legacy VFIO application exists. > > > > > + > > > > > +So far SPAPR does not support IOMMUFD yet. So it cannot support device > > > > > +cdev either. > > > > > > > > Why isn´t this enforced via Kconfig? At the vfio level we could simply > > > > add the following in patch 17/: > > > > > > > > config VFIO_DEVICE_CDEV > > > > bool "Support for the VFIO cdev /dev/vfio/devices/vfioX" > > > > depends on IOMMUFD && !SPAPR_TCE_IOMMU > > > > ^^^^^^^^^^^^^^^^^^^ > > > > > > Proposal A. > > > > > Or if Jason wants, IOMMUFD could depend on !SPAPR_TCE_IOMMU for now and > > > > the existing Kconfig options would exclude it. If we know it doesn't > > > > work, let's not put the burden on the user to figure that out. A > > > > follow-up patch for this would be fine if there's no other reason to > > > > respin the series. > > Proposal B. > > > > > > > @Jason, > > > How about your opinion? Seems reasonable to make IOMMUFD > > > depend on !SPAPR_TCE_IOMMU. Is it? > > > > The right kconfig would be to list all the iommu drivers that can > > support iommufd and allow it to be selected if any of them are > > enabled. > > > > This seems too complex to bother with, so I like Alex's version above.. > > Sorry, I'm not quite clear. Alex has two proposals above (A and B). Which > one do you mean? It looks like you prefer A. is it? :-) A Jason
