Re: [PATCH v4 0/7] Make the rest of the VFIO driver interface use vfio_device

[Alex Williamson <alex.williamson@redhat.com>]

On Thu,  5 May 2022 21:08:38 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:

> Prior series have transformed other parts of VFIO from working on struct
> device or struct vfio_group into working directly on struct
> vfio_device. Based on that work we now have vfio_device's readily
> available in all the drivers.
> 
> Update the rest of the driver facing API to use vfio_device as an input.
> 
> The following are switched from struct device to struct vfio_device:
>   vfio_register_notifier()
>   vfio_unregister_notifier()
>   vfio_pin_pages()
>   vfio_unpin_pages()
>   vfio_dma_rw()
> 
> The following group APIs are obsoleted and removed by just using struct
> vfio_device with the above:
>   vfio_group_pin_pages()
>   vfio_group_unpin_pages()
>   vfio_group_iommu_domain()
>   vfio_group_get_external_user_from_dev()
> 
> To retain the performance of the new device APIs relative to their group
> versions optimize how vfio_group_add_container_user() is used to avoid
> calling it when the driver must already guarantee the device is open and
> the container_users incrd.
> 
> The remaining exported VFIO group interfaces are only used by kvm, and are
> addressed by a parallel series.
> 
> This series is based on Christoph's gvt rework here:
> 
>  https://lore.kernel.org/all/5a8b9f48-2c32-8177-1c18-e3bd7bfde558@intel.com/
> 
> and so will need the PR merged first.
> 
> I have a followup series that needs this.
> 
> This is also part of the iommufd work - moving the driver facing interface
> to vfio_device provides a much cleaner path to integrate with iommufd.
> 
> v4:
>  - Use 'device' as the argument name for a struct vfio_device in vfio.c
> v3: https://lore.kernel.org/r/0-v3-e131a9b6b467+14b6-vfio_mdev_no_group_jgg@nvidia.com
>  - Based on VFIO's gvt/iommu merge
>  - Remove mention of mdev_legacy_get_vfio_device() from commit message
>  - Clarify commit message for vfio_dma_rw() conversion
>  - Talk about the open_count change in the commit message
>  - No code change
> v2: https://lore.kernel.org/r/0-v2-6011bde8e0a1+5f-vfio_mdev_no_group_jgg@nvidia.com
>  - Based on Christoph's series so mdev_legacy_get_vfio_device() is removed
>  - Reflow indenting
>  - Use vfio_assert_device_open() and WARN_ON_ONCE instead of open coding
>    the assertion
> v1: https://lore.kernel.org/r/0-v1-a8faf768d202+125dd-vfio_mdev_no_group_jgg@nvidia.com
> 
> Jason Gunthorpe (7):
>   vfio: Make vfio_(un)register_notifier accept a vfio_device
>   vfio/ccw: Remove mdev from struct channel_program
>   vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages()
>   vfio/mdev: Pass in a struct vfio_device * to vfio_dma_rw()
>   drm/i915/gvt: Change from vfio_group_(un)pin_pages to
>     vfio_(un)pin_pages
>   vfio: Remove dead code
>   vfio: Remove calls to vfio_group_add_container_user()
> 
>  .../driver-api/vfio-mediated-device.rst       |   4 +-
>  drivers/gpu/drm/i915/gvt/gvt.h                |   5 +-
>  drivers/gpu/drm/i915/gvt/kvmgt.c              |  51 ++-
>  drivers/s390/cio/vfio_ccw_cp.c                |  47 +--
>  drivers/s390/cio/vfio_ccw_cp.h                |   4 +-
>  drivers/s390/cio/vfio_ccw_fsm.c               |   3 +-
>  drivers/s390/cio/vfio_ccw_ops.c               |   7 +-
>  drivers/s390/crypto/vfio_ap_ops.c             |  23 +-
>  drivers/vfio/vfio.c                           | 299 +++---------------
>  include/linux/vfio.h                          |  21 +-
>  10 files changed, 109 insertions(+), 355 deletions(-)

Applied to vfio next branch for v5.19.  Thanks,

Alex