Grant Grundler wrote:
> On Thu, Jan 08, 2009 at 12:05:38PM -0800, Dirk Hohndel wrote:
>>
>> latest git from Linus. On a Thinkpad x200s with VT-d enabled (if I
>> disable VT-d, this of course goes away).
>>
>> The oops happens very early during boot in device_to_iommu (called
>> from domain_context_mapping_one).
>>
>> Looking at the code dump and the disassembled function here's where
>> the error happens:
>>
>> static struct intel_iommu *device_to_iommu(u8 bus, u8 devfn) {
>> struct dmar_drhd_unit *drhd = NULL;
>> int i;
>>
>> for_each_drhd_unit(drhd) {
>> if (drhd->ignored)
>> continue;
>>
>> for (i = 0; i < drhd->devices_cnt; i++)
>> if (drhd->devices[i]->bus->number == bus &&
>> --> drhd->devices[0] is NULL
>> drhd->devices[i]->devfn == devfn)
>> return drhd->iommu;
>>
>>
>> Given how early this happens it's a little hard to provide logs,
>> etc. I literally used delay_boot=100 and wrote things down by hand
>> (forgot my digital camera) and then added printk's to verify).
>>
>> please let me know what other data I should collect.
>
> If you can, a back trace. Basically just need to know which caller
> is tripping over this. But there can't be that many callers and they
> are all in this file:
> 0 intel-iommu.c device_to_iommu 431 static struct
> intel_iommu *device_to_iommu(u8 bus, u8 devfn) 1 intel-iommu.c
> domain_context_mapping_on 1471 iommu = device_to_iommu(bus, devfn); 2
> intel-iommu.c domain_context_mapped 1593 iommu =
> device_to_iommu(pdev->bus->number, pdev->devfn); 3 intel-iommu.c
> domain_remove_dev_info 1684 iommu = device_to_iommu(info->bus,
> info->devfn); 4 intel-iommu.c vm_domain_remove_one_dev_ 2773 iommu =
> device_to_iommu(pdev->bus->number, pdev->devfn); 5 intel-iommu.c
> vm_domain_remove_one_dev_ 2803 if (device_to_iommu(info->bus,
> info->devfn) == iommu) 6 intel-iommu.c vm_domain_remove_all_dev_ 2836
> iommu = device_to_iommu(info->bus, info->devfn); 7 intel-iommu.c
> intel_iommu_attach_device 3023 iommu =
> device_to_iommu(pdev->bus->number, pdev->devfn);
>
> so it should be possible to figure out which one is called
> before the dev is setup. It's unlikely to be anything with
> "remove" in the name. :)
>
> My guess is it's intel_iommu_attach_device being called "too early".
yes, pls get the call trace. When device_to_iommu() is called, DMAR should be already parsed from acpi table and registered, so device_to_iommu() should not fail unless it's called earlier than DMAR is parsed and registered.
Regards,
Weidong
>
> hth,
> grant
>
>
> hth,
> grant
>
>>
>> The system ran fine with the 2.6.28 release kernel.
>>
>> /D
>>
>> --
>> Dirk Hohndel
>> Intel Open Source Technology Center
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci"
>> in the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> _______________________________________________
> iommu mailing list
> iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
> https://lists.linux-foundation.org/mailman/listinfo/iommu
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
