Re: 3.9-rc1: crash kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer

Yinghai Lu
2013-03-08T07:50:03Z

On Thu, Mar 7, 2013 at 11:33 PM, WANG Chao <chaowang@redhat.com> wrote:
> On 03/08/2013 03:27 PM, Yinghai Lu wrote:
>> On Thu, Mar 7, 2013 at 11:20 PM, WANG Chao <chaowang@redhat.com> wrote:
>>>>
>>>> looks like your system DO have DMAR table, please enable dmar
>>>> remapping in your kernel config.
>>>
>>> I've already got following config:
>>> CONFIG_DMAR_TABLE=y
>>> CONFIG_INTEL_IOMMU=y
>>> CONFIG_IRQ_REMAP=y
>>>
>>> but I don't have intel_iommu=on in kernel cmdline. IIRC, iommu will prevent
>>> 2nd kernel from booting ...
>>
>> Did you put intel_iommu=on on first and second cpu both?
>
> I tried, 2nd kernel didn't boot and keep splitting errors like these:
> [ 2.106939] DMAR: No ATSR found
> [ 2.110121] IOMMU 0 0xfed90000: using Queued invalidation
> [ 2.115522] IOMMU 1 0xfed91000: using Queued invalidation
> [ 2.120919] IOMMU: Setting RMRR:
> [ 2.124162] IOMMU: Setting identity map for device 0000:00:02.0 [0xab800000
> - 0xaf9fffff]
> [ 2.133099] IOMMU: Setting identity map for device 0000:00:1d.0 [0xaac95000
> - 0xaacb2fff]
> [ 2.141305] IOMMU: Setting identity map for device 0000:00:1a.0 [0xaac95000
> - 0xaacb2fff]
> [ 2.149503] IOMMU: Setting identity map for device 0000:00:14.0 [0xaac95000
> - 0xaacb2fff]
> [ 2.157690] IOMMU: Prepare 0-16MiB unity mapping for LPC
> [ 2.163011] IOMMU: Setting identity map for device 0000:00:1f.0 [0x0 - 0xffffff
> [Errors, here we go]
> [ 2.170932] dmar: DRHD: handling fault status reg 3
> [ 2.170933] PCI-DMA: Intel(R) Virtualization Technology for Directed I/O
> [ 2.182486] dmar: DMAR:[DMA Write] Request device [00:02.0] fault addr ffffe000
> [ 2.182486] DMAR:[fault reason 05] PTE Write access is not set
> [ 2.195705] dmar: DRHD: handling fault status reg 3
> [ 2.200570] dmar: DMAR:[DMA Read] Request device [00:02.0] fault addr ff873000
> [ 2.200570] DMAR:[fault reason 06] PTE Read access is not set
> [ 2.213618] dmar: DRHD: handling fault status reg 3

my Nehalem-EX and Westmere-EX is working with iommu enabled in second kernel.

what is 00:02.0 in your system?

Is your kernel upsteam kernel or redhat flavor one?

Thanks