Re: [PATCH 00/22] media: iris: Restrict lower IOVA range for Venus and Iris VPUs

Bryan O'Donoghue <[email protected]> Fri, 7 Aug 2026 09:51:22 +0100
Newsgroups org.kernel.vger.linux-media,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.stable
Message-ID <[email protected]>
On 07/08/2026 09:24, Vikash Garodia wrote:
> Qualcomm venus and iris VPUs reserve IOVA addresses below 0x25800000
> (600MB) for non-pixel stream ID in secure mode. When the kernel
> allocates DMA mappings from this restricted range, the VPU generate
> unhandled SMMU page faults, leading to video failures and, in some
> cases, spontaneous system reboots.
> 
> The issue is readily reproducible on affected platforms by running
> multiple concurrent video decode workloads, such as opening several
> browser tabs containing video streams.
> 
> To prevent allocations in the restricted region, this series introduces
> support for an IOMMU IOVA reserve memory-region in the Venus and Iris
> bindings and updates all affected device trees to reserve the low IOVA
> range [0, 0x25800000]. The memory-region is referenced by the video codec
> node, allowing the IOMMU layer to keep DMA allocations above the reserved
> boundary.
> 
> The series consists of:
> 
>    * Binding updates for Venus and Iris schemas to permit an additional
>      memory-region phandle describing the IOVA reservation.
>    * DTS updates for all affected Venus platforms.
>    * DTS updates for all affected Iris platforms.
> 
> This ensures that DMA allocations do not overlap restricted IOVA
> mappings for non-pixel stream IDs and prevents the resulting SMMU
> faults.
LGTM

For the series.

Reviewed-by: Bryan O'Donoghue <[email protected]>

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