On Tue, Oct 10, 2023 at 12:03:29PM -0400, Michael S. Tsirkin wrote: > On Tue, Oct 10, 2023 at 12:59:37PM -0300, Jason Gunthorpe wrote: > > On Tue, Oct 10, 2023 at 11:14:56AM -0400, Michael S. Tsirkin wrote: > > > > > I suggest 3 but call it on the VF. commands will switch to PF > > > internally as needed. For example, intel might be interested in exposing > > > admin commands through a memory BAR of VF itself. > > > > FWIW, we have been pushing back on such things in VFIO, so it will > > have to be very carefully security justified. > > > > Probably since that is not standard it should just live in under some > > intel-only vfio driver behavior, not in virtio land. > > > > It is also costly to switch between pf/vf, it should not be done > > pointlessly on the fast path. > > > > Jason > > Currently, the switch seems to be just a cast of private data. > I am suggesting keeping that cast inside virtio. Why is that > expensive? pci_iov_get_pf_drvdata() does a bunch of sanity checks and function calls. It was not intended to be used on a fast path. Jason
