On Mon, May 16, 2022 at 02:30:46PM -0400, Matthew Rosato wrote: > Conceptually I think this would work for QEMU anyway (it always sets the kvm > before we open the device). I tried to test the idea quickly but couldn't > get the following to apply on vfio-next or your vfio_group_locking -- but I > understand what you're trying to do so I'll re-work and try it out. I created it on 8c9350e9bf43de1ebab3cc8a80703671e6495ab4 which is the vfio_group_locking.. I can send you a github if it helps https://github.com/jgunthorpe/linux/commits/vfio_group_lockin > @Alex can you think of any usecase/reason why we would need to be able to > set the KVM sometime after the device was opened? Doing something like > below would break that, as this introduces the assumption that the group is > associated with the KVM before the device is opened (and if it's not, the > device open fails). Keep in mind that GVT already hard requires this ordering to even allow open_device to work - so it already sets a floor for what userspace can do.. Jason
