Messages in this thread | | | Date | Tue, 28 Nov 2023 10:43:31 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 1/2] iommufd/selftest: Use a fwnode to distinguish devices |
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On Tue, Nov 28, 2023 at 10:42:11AM +0000, Robin Murphy wrote: > With bus ops gone, the trick of registering against a specific bus no > longer really works, and we start getting given devices from other buses > to probe,
Make sense
> which leads to spurious groups for devices with no IOMMU on > arm64,
I'm not sure I'm fully understanding what this means?
I guess that the mock driver is matching random things once it starts being called all the time because this is missing:
static struct iommu_device *mock_probe_device(struct device *dev) { + if (dev->bus != &iommufd_mock_bus_type) + return -ENODEV; return &mock_iommu_device; }
Is that sufficient to solve the problem?
> but may inadvertently steal devices from the real IOMMU on Intel, > AMD or S390.
AMD/Intel/S390 drivers already reject bus's they don't understand.
Intel's device_to_iommu() will fail because for_each_active_dev_scope() will never match the mock device.
amd fails because check_device() -> get_device_sbdf_id() fails due to no PCI and not get_acpihid_device_id().
s390 fails because !dev_is_pci(dev).
The fwspec drivers should all fail if they don't have a fwspec, and they shouldn't for mock bus devices since it doesn't implement dma_configure.
Jason
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