Re: [PATCH v3 5/5] pci: Suspend iommu function prior to resetting a device

Nicolin Chen
2025-08-28T15:08:48Z

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