Re: [PATCH v4 02/14] iommufd/viommu: Add IOMMU_VDEVICE_ALLOC ioctl

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2024/10/22 8:20, Nicolin Chen wrote:
> Introduce a new ioctl to allocate a vDEVICE object. Since a vDEVICE object
> is a connection of an iommufd_iommufd object and an iommufd_viommu object,

nit:

:s/iommufd_iommufd/iommufd_device/g

or not?

> require both as the ioctl inputs and take refcounts in the ioctl handler.
> 
> Add to the vIOMMU object a "vdevs" xarray, indexed by a per-vIOMMU virtual
> device ID, which can be:
>   - Virtual StreamID on a nested ARM SMMUv3, an index to a Stream Table
>   - Virtual DeviceID on a nested AMD IOMMU, an index to a Device Table
>   - Virtual ID on a nested Intel VT-D IOMMU, an index to a Context Table
> 
> Then, let the idev structure hold the allocated vdev pointer with a proper
> locking protection.
> 
> Signed-off-by: Nicolin Chen<nicolinc@nvidia.com>
> ---
>   drivers/iommu/iommufd/iommufd_private.h |  12 +++
>   include/linux/iommufd.h                 |   2 +
>   include/uapi/linux/iommufd.h            |  26 ++++++
>   drivers/iommu/iommufd/device.c          |  11 +++
>   drivers/iommu/iommufd/main.c            |   7 ++
>   drivers/iommu/iommufd/viommu.c          | 108 ++++++++++++++++++++++++
>   6 files changed, 166 insertions(+)

Thanks,
baolu