RE: [PATCH v2 0/6] IOMMUFD: Deliver IO page faults to user space

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Lu Baolu [mailto:baolu.lu@xxxxxxxxxxxxxxx]
> Sent: 26 October 2023 03:49
> To: Jason Gunthorpe <jgg@xxxxxxxx>; Kevin Tian <kevin.tian@xxxxxxxxx>;
> Joerg Roedel <joro@xxxxxxxxxx>; Will Deacon <will@xxxxxxxxxx>; Robin
> Murphy <robin.murphy@xxxxxxx>; Jean-Philippe Brucker
> <jean-philippe@xxxxxxxxxx>; Nicolin Chen <nicolinc@xxxxxxxxxx>; Yi Liu
> <yi.l.liu@xxxxxxxxx>; Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Cc: iommu@xxxxxxxxxxxxxxx; linux-kselftest@xxxxxxxxxxxxxxx;
> virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Lu
> Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Subject: [PATCH v2 0/6] IOMMUFD: Deliver IO page faults to user space
> 
> Hi folks,
> 
> This series implements the functionality of delivering IO page faults to
> user space through the IOMMUFD framework for nested translation. Nested
> translation is a hardware feature that supports two-stage translation
> tables for IOMMU. The second-stage translation table is managed by the
> host VMM, while the first-stage translation table is owned by user
> space. This allows user space to control the IOMMU mappings for its
> devices.
> 
> When an IO page fault occurs on the first-stage translation table, the
> IOMMU hardware can deliver the page fault to user space through the
> IOMMUFD framework. User space can then handle the page fault and
> respond
> to the device top-down through the IOMMUFD. This allows user space to
> implement its own IO page fault handling policies.
> 
> User space indicates its capability of handling IO page faults by
> setting the IOMMU_HWPT_ALLOC_IOPF_CAPABLE flag when allocating a
> hardware page table (HWPT). IOMMUFD will then set up its infrastructure
> for page fault delivery. On a successful return of HWPT allocation, the
> user can retrieve and respond to page faults by reading and writing to
> the file descriptor (FD) returned in out_fault_fd.
> 
> The iommu selftest framework has been updated to test the IO page fault
> delivery and response functionality.
> 
> This series is based on the latest implementation of nested translation
> under discussion [1] and the page fault handling framework refactoring in
> the IOMMU core [2].
> 
> The series and related patches are available on GitHub: [3]
> 
> [1]
> https://lore.kernel.org/linux-iommu/20230921075138.124099-1-yi.l.liu@int
> el.com/
> [2]
> https://lore.kernel.org/linux-iommu/20230928042734.16134-1-baolu.lu@li
> nux.intel.com/
> [3]
> https://github.com/LuBaolu/intel-iommu/commits/iommufd-io-pgfault-deliv
> ery-v2

Hi Baolu,

Do you have a corresponding Qemu git to share? I could give it a spin on our ARM 
platform. Please let me know.

Thanks,
Shameer