On Thu, Aug 28, 2025 at 09:51:49AM -0300, Jason Gunthorpe wrote: > On Fri, Aug 22, 2025 at 11:50:58AM -0700, Nicolin Chen wrote: > > > It feels like we need a no-fail re-attach operation, or at least an > > unlikely-to-fail one. I recall years ago we tried a can_attach op > > to test the compatibility but it didn't get merged. Maybe we'd need > > it so that a concurrent attach can test compatibility, allowing the > > re-attach in iommu_dev_reset_done() to more likely succeed. > > This is probably the cleanest option to split these things Yea, that could avoid failing a concurrent attach_dev during FLR unless the dryrun fails, helping non-SRIOV cases too. So, next version could have some new preparatory patches: - Pass in old domain to attach_dev - Add a can_attach_dev op Thanks Nicolin