Re: [PATCH v2 3/7] iommu: Add iommu_report_device_broken() to quarantine a broken device

From: Nicolin Chen

Date: Wed Mar 18 2026 - 21:33:59 EST


On Wed, Mar 18, 2026 at 02:13:09PM +0800, Baolu Lu wrote:
> On 3/18/26 03:15, Nicolin Chen wrote:
> > + scoped_guard(mutex, &group->mutex) {
> > + /* Do not block the device again if it has been recovered */
> > + if (!READ_ONCE(group->requires_reset))
> > + goto out_put;
> > + if (list_is_singular(&group->devices)) {
> > + /* Note: only support group with a single device */
> > + dev = iommu_group_first_dev(group);
> > + if (dev_is_pci(dev)) {
> > + pdev = to_pci_dev(dev);
> > + pci_dev_get(pdev);
> > + }
> > + }
>
> The current mechanism is designed only for the PCIe devices within
> singleton iommu groups. How about moving the above check to
> iommu_report_device_broken() and emitting a message if it is called for
> unsupported devices?

Yes. That would be cleaner.

Thanks
Nicolin