> From: Alex Williamson <alex.williamson@xxxxxxxxxx> > Sent: Wednesday, June 28, 2023 1:35 AM [The Cc list gets broken in the reply from Alex to Jason, here I reply to Alex's email with the Cc list fixed. @Alex, seems like the same symptom with last time, do you have any idea on it?] > On Tue, 27 Jun 2023 13:12:14 -0300 > Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > > > 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 > > > > ^^^^^^^^^^^^^^^^^^^ > > > > > > > > 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. > > > > > > @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.. > > > > > > Otherwise the series is looking pretty good to me. It still requires > > > > some reviews/acks in the iommufd space and it would be good to see more > > > > reviews for the remainder given the amount of collaboration here. > > > > > > > > I'm out for the rest of the week, but I'll leave open accepting this > > > > and the hot-reset series next week for the merge window. Thanks, > > > > > > @Alex, > > > Given Jason's remarks on cdev v12, I've already got a new version as below. > > > I can post it once the above kconfig open is closed. > > > > I think we don't need to bend the rules, Linus would not be happy to > > see 30 major patches that never hit linux-next at all. > > > > I'm happy if we put it on a branch at RC1 and merge it to the vfio & > > iommufd trees, it is functionally the same outcome in the same time > > frame. > > Not sure I'm clear on the plan. My intention would have been to apply > v14 to my next branch, make sure it did see linux-next exposure, > and send a pull request for rc1 next week. > > Are you suggesting a post-merge-window pull request for v6.5 (also > frowned on) or are you suggesting that it simmers in both our next > branches until v6.6? Thanks, It appears to me the latter one. When 6.5-rc1 is released, we immediately apply the hot-reset and cdev series onto it and put it in a shared tree to assist the other iommufd feature development (e.g. nesting). Jason, is it? Regards, Yi Liu
