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

[Andy Shevchenko]

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.

I'm wondering if IPU MMU should be described properly in the DMAR table.

-- 
With Best Regards,
Andy Shevchenko