Re: [PATCH v4 02/27] backends/iommufd: Introduce iommufd_vdev_alloc

[Jonathan Cameron via <qemu-arm@nongnu.org>]

On Mon, 29 Sep 2025 14:36:18 +0100
Shameer Kolothum <skolothumtho@nvidia.com> wrote:

> From: Nicolin Chen <nicolinc@nvidia.com>
> 
> Add a helper to allocate an iommufd device's virtual device (in the user
> space) per a viommu instance.
> 
> While at it, introduce a struct IOMMUFDVdev for later use by vendor
> IOMMU implementations.
> 
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>

A theme emerging.  See below.
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

> diff --git a/include/system/iommufd.h b/include/system/iommufd.h
> index dfe1dc2850..e852193f35 100644
> --- a/include/system/iommufd.h
> +++ b/include/system/iommufd.h
> @@ -48,6 +48,14 @@ typedef struct IOMMUFDViommu {
>      uint32_t viommu_id;  /* virtual IOMMU ID of allocated object */
>  } IOMMUFDViommu;
>  
> +/*
> + * Virtual device object for a physical device bind to a vIOMMU.
> + */
> +typedef struct IOMMUFDVdev {
> +    uint32_t vdev_id; /*  Virtual device ID */
> +    uint32_t dev_id;  /*  Physical device ID */

Spacing and capitalization is a bit is consistent... Previous patch had lowercase v in
similar comments.

> +} IOMMUFDVdev;
> +
>  bool iommufd_backend_connect(IOMMUFDBackend *be, Error **errp);
>  void iommufd_backend_disconnect(IOMMUFDBackend *be);
>  
> @@ -73,6 +81,10 @@ bool iommufd_backend_alloc_viommu(IOMMUFDBackend *be, uint32_t dev_id,
>                                    uint32_t viommu_type, uint32_t hwpt_id,
>                                    uint32_t *out_hwpt, Error **errp);
>  
> +bool iommufd_backend_alloc_vdev(IOMMUFDBackend *be, uint32_t dev_id,
> +                                uint32_t viommu_id, uint64_t virt_id,
> +                                uint32_t *out_vdev_id, Error **errp);
> +
>  bool iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, uint32_t hwpt_id,
>                                          bool start, Error **errp);
>  bool iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,