Re: [RESEND v2] iommu/vt-d: Use passthrough mode for the Intel IPUs

From: Bingbu Cao
Date: Tue Apr 20 2021 - 06:41:33 EST


Andy,

On 4/20/21 6:20 PM, Andy Shevchenko wrote:
> On Tue, Apr 20, 2021 at 10:48:33AM +0800, Bingbu Cao wrote:
>> Intel IPU(Image Processing Unit) has its own (IO)MMU hardware,
>> The IPU driver allocates its own page table that is not mapped
>> via the DMA, and thus the Intel IOMMU driver blocks access giving
>> this error:
>>
>> DMAR: DRHD: handling fault status reg 3
>> DMAR: [DMA Read] Request device [00:05.0] PASID ffffffff
>> fault addr 76406000 [fault reason 06] PTE Read access is not set
>>
>> As IPU is not an external facing device which is not risky, so use
>> IOMMU passthrough mode for Intel IPUs.
>>
>> Fixes: 26f5689592e2 ("media: staging/intel-ipu3: mmu: Implement driver")
>> Signed-off-by: Bingbu Cao <bingbu.cao@xxxxxxxxx>
>> ---
>> drivers/iommu/intel/iommu.c | 29 +++++++++++++++++++++++++++++
>
> This misses the changelog from v1 followed by the explanation why resent.
>
I noticed there was a typo in the recipient list:
stable.vger.kernel.org -> stable@xxxxxxxxxxxxxxx

no code change for resent.

--
Best regards,
Bingbu Cao