On Thu, Aug 28, 2025 at 03:46:08PM -0300, Jason Gunthorpe wrote: > On Thu, Aug 28, 2025 at 08:08:13AM -0700, Nicolin Chen wrote: > > 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 > > I wouldn't make this more complicated, just focus on the signal device > case here then we move on from there > > Just adding can_attach_dev is big series on its own OK. I suppose a concurrent attach on a single device will be rare, so failing it won't impact that much and thus can be a Part-1. Then, for part-2, we will do can_attach_dev and support SRIOV. Thanks Nicolin
