Messages in this thread |  | | Date | Sat, 23 Apr 2022 16:01:59 +0800 | Subject | Re: [PATCH 02/13] iommu: Move bus setup to IOMMU device registration | From | Lu Baolu <> |
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Hi Robin,
On 2022/4/19 15:20, Robin Murphy wrote: > On 2022-04-19 00:37, Lu Baolu wrote: >> On 2022/4/19 6:09, Robin Murphy wrote: >>> On 2022-04-16 01:04, Lu Baolu wrote: >>>> On 2022/4/14 20:42, Robin Murphy wrote: >>>>> @@ -1883,27 +1900,12 @@ static int iommu_bus_init(struct bus_type >>>>> *bus) >>>>> */ >>>>> int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops) >>>>> { >>>>> - int err; >>>>> - >>>>> - if (ops == NULL) { >>>>> - bus->iommu_ops = NULL; >>>>> - return 0; >>>>> - } >>>>> - >>>>> - if (bus->iommu_ops != NULL) >>>>> + if (bus->iommu_ops && ops && bus->iommu_ops != ops) >>>>> return -EBUSY; >>>>> bus->iommu_ops = ops; >>>> >>>> Do we still need to keep above lines in bus_set_iommu()? >>> >>> It preserves the existing behaviour until each callsite and its >>> associated error handling are removed later on, which seems like as >>> good a thing to do as any. Since I'm already relaxing >>> iommu_device_register() to a warn-but-continue behaviour while it >>> keeps the bus ops on life-support internally, I figured not changing >>> too much at once would make it easier to bisect any potential issues >>> arising from this first step. >> >> Fair enough. Thank you for the explanation. >> >> Do you have a public tree that I could pull these patches and try them >> on an Intel hardware? Or perhaps you have done this? I like the whole >> idea of this series, but it's better to try it with a real hardware. > > I haven't bothered with separate branches since there's so many > different pieces in-flight, but my complete (unstable) development > branch can be found here: > > https://gitlab.arm.com/linux-arm/linux-rm/-/commits/iommu/bus > > For now I'd recommend winding the head back to "iommu: Clean up > bus_set_iommu()" for testing - some of the patches above that have > already been posted and picked up by their respective subsystems, but > others are incomplete and barely compile-tested. I'll probably rearrange > it later this week to better reflect what's happened so far.
I wound the head back to "iommu: Clean up bus_set_iommu" and tested it on an Intel machine. It got stuck during boot. This test was on a remote machine and I have no means to access it physically. So I can't get any kernel debugging messages. (I have to work from home these days. :-()
I guess it's due to the fact that intel_iommu_probe_device() callback only works for the pci devices. The issue occurs when probing a device other than a PCI one.
Best regards, baolu
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