> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Saturday, February 25, 2023 8:28 AM > > These items only needs to be done once per group, not once per device. The > once per device was a way to make the device list work. Since we are > abandoning this we can optimize things a bit. > Are we sure that a device hot-plugged into the group won't increase the list of reserved IOVA ranges? Currently iommu_get_group_resv_regions() queries reserved regions per device and then merge them into the specified list. Of course VFIO cannot cope with it since its group_attach() is done only once. But if such scenario does exist then the current per-device reservation in iommufd looks an improvement.
