On Thu, Dec 08, 2022 at 02:48:25PM -0700, Alex Williamson wrote: > On Thu, 8 Dec 2022 16:26:29 -0400 > Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > > > iommu_group_for_each_dev() exits the loop at the first callback that > > returns 1 - thus returning 1 fails to check the rest of the devices in the > > group. > > > > msi_remap (aka secure MSI) requires that all the devices in the group > > support it, not just any one. This is only a theoretical problem as no > > current drivers will have different secure MSI properties within a group. > > Which is exactly how Robin justified the behavior in the referenced > commit: > > As with domains, any capability must in practice be consistent for > devices in a given group - and after all it's still the same > capability which was expected to be consistent across an entire bus! > - so there's no need for any complicated validation. > > That suggests to me that it's intentional that we break if any device > supports the capability and therefore this isn't so much a "Fixes:", as > it is a refactoring expressly to support msi_device_has_secure_msi(), > which cannot make these sort of assumptions as a non-group API. Thanks, Sure, lets drop the fixes and your analysis seems correct Jason
