Re: [PATCH v12 00/16] iommu: Prepare to deliver page faults to user space

Baolu Lu
2024-02-09T02:39:52Z

On 2024/2/8 17:03, Zhangfei Gao wrote:
> Hi, Baolu
>
> On Wed, 7 Feb 2024 at 09:39, Lu Baolu <baolu.lu@linux.intel.com
> <mailto:baolu.lu@linux.intel.com>> wrote:
>
> When a user-managed page table is attached to an IOMMU, it is necessary
> to deliver IO page faults to user space so that they can be handled
> appropriately. One use case for this is nested translation, which is
> currently being discussed in the mailing list.
>
> I have posted a RFC series [1] that describes the implementation of
> delivering page faults to user space through IOMMUFD. This series has
> received several comments on the IOMMU refactoring, which I am trying to
> address in this series.
>
> The major refactoring includes:
>
> - [PATCH 01 ~ 04] Move include/uapi/linux/iommu.h to
>   include/linux/iommu.h. Remove the unrecoverable fault data
> definition.
> - [PATCH 05 ~ 06] Remove iommu_[un]register_device_fault_handler().
> - [PATCH 07 ~ 10] Separate SVA and IOPF. Make IOPF a generic page fault
>   handling framework.
> - [PATCH 11 ~ 16] Improve iopf framework.
>
> This is also available at github [2].
>
> [1]
> https://lore.kernel.org/linux-iommu/20230530053724.232765-1-baolu.lu@linux.intel.com/ <https://lore.kernel.org/linux-iommu/20230530053724.232765-1-baolu.lu@linux.intel.com/>
> [2]
> https://github.com/LuBaolu/intel-iommu/commits/preparatory-io-pgfault-delivery-v12 <https://github.com/LuBaolu/intel-iommu/commits/preparatory-io-pgfault-delivery-v12>
>
>
> Wandering are these patches dropped now,
>
> [PATCH v2 2/6] iommufd: Add iommu page fault uapi data
> https://lore.kernel.org/lkml/20231026024930.382898-3-baolu.lu@linux.intel.com/raw <https://lore.kernel.org/lkml/20231026024930.382898-3-baolu.lu@linux.intel.com/raw>
>
> [PATCH v2 4/6] iommufd: Deliver fault messages to user space
> https://lore.kernel.org/lkml/20231026024930.382898-5-baolu.lu@linux.intel.com/ <https://lore.kernel.org/lkml/20231026024930.382898-5-baolu.lu@linux.intel.com/>

Above patches are part of another series named "IOMMUFD: Deliver IO page
faults to user space", which is now updated to v3.

https://lore.kernel.org/linux-iommu/20240122073903.24406-1-baolu.lu@linux.intel.com/

> And does iouring still be used in user space?

iouring is not related to this series. For uapi of iommufd, it's still
recommended to use iouring to speed up the handling of faults.

Best regards,
baolu