On Sun, Feb 26, 2023 at 08:59:01AM +0000, Liu, Yi L wrote: > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Sent: Friday, February 24, 2023 10:36 AM > > > > On Fri, Feb 24, 2023 at 02:21:33AM +0000, Tian, Kevin wrote: > > > > > Yi, while you are incorporating this change please also update the > > > uapi header. Rename 'group_fds[]' to 'fds[]' and add comment to > > > explain that it could be an array of group fds or a single iommufd. > > > > Upon reflection we can probably make it even simpler and just have a 0 > > length fd array mean to use the iommufd the vfio_device is already > > associated with > > > > And the check for correctness can be simplified to simply see if each > > vfio_device in the dev_set is attached to the same iommufd ctx > > pointer instead of searching the xarray. > > Sorry, it appears to me the below concern is not solved as above logic > still requires userspace to open and bind devices to the same iommufd. > > " > > Say a scenario where group happens to overlap with devset. Let's say > > two devices in the group/devset. > > > > An existing deployment assigns only dev1 to Qemu. In this case dev1 > > is resettable via group fd given dev2 cannot be opened by another > > user. > " You solve this by checking for a 0 open count as already discussed. Jason
