Re: [Qemu-devel] [PATCH v11 00/22] Add Mediated device support

[Alexey Kardashevskiy]

On 05/11/16 08:10, Kirti Wankhede wrote:
> This series adds Mediated device support to Linux host kernel. Purpose
> of this series is to provide a common interface for mediated device
> management that can be used by different devices. This series introduces
> Mdev core module that creates and manages mediated devices, VFIO based
> driver for mediated devices that are created by mdev core module and
> update VFIO type1 IOMMU module to support pinning & unpinning for mediated
> devices.
> 
> What changed in v11?
> mdev core:
>   Register mdev_bus class when first device is registed to avoid panic if
>   any vendor driver and mdev driver are selected as built-in but vendor
>   driver loads first and then mdev module.
> vfio_mdev:
>   Added notifier callback function to mdev parent's ops so that notifer
>   is registered from vfio_mdev module during device open and unregistered
>   it from device close call. This is a optional callback. Some drivers
>   using mdev framework might not pin or unpin pages, for example the
>   sample mtty driver that simulates serial port. Vendor driver who need to
>   pin/unpin pages should provide this callback. Otherwise pin request
>   would fail.
> vfio_iommu_type1:
>   Updated to keep track of who (task and address space) mapped iova range.
>   During DMA_UNMAP, same task who mapped it or other task who shares same
>   address space is allowed to unmap, otherwise unmap fails.
>   QEMU maps few iova ranges initially, then fork threads and from the child
>   thread calls DMA_UNMAP on previously mapped iova. Since child shares same
>   address space, DMA_UNMAP is successful.
>   Address space keeps track of pages pinned (pfn_list) by external user /
>   mdev devices. This pfn_list is used to verify pfn during unpin_request,
>   re-accounting of pages when direct device assigned in hot-unplugged and
>   mdev device is present in same container.
>   When the container is released, all mapped iova from all tasks are
>   unmapped and removed.
> 
>   Tested by assigning below combinations of devices to a single VM:
>    - GPU pass through only
>    - vGPU device only
>    - One GPU pass through and one vGPU device
>    - Linux VM hot plug and unplug vGPU device while GPU pass through device
>      exist
>    - Linux VM hot plug and unplug GPU pass through device while vGPU device
>      exist
> 
>   Patch series tested with linux-next upto commit 14970f204b19 @Fri Oct 28
>   Resolved against conflicting change:

Patch 11/22 does not apply if the patchset is applied on top of 14970f204b19.



>   05692d7005a3 vfio/pci: Fix integer overflows, bitmask check
> 
> 
> Kirti Wankhede (22):
>   vfio: Mediated device Core driver
>   vfio: VFIO based driver for Mediated devices
>   vfio: Rearrange functions to get vfio_group from dev
>   vfio: Common function to increment container_users
>   vfio iommu: Added pin and unpin callback functions to
>     vfio_iommu_driver_ops
>   vfio iommu type1: Update arguments of vfio_lock_acct
>   vfio iommu type1: Update argument of vaddr_get_pfn()
>   vfio iommu type1: Add find_iommu_group() function
>   vfio iommu type1: Add task structure to vfio_dma
>   vfio iommu type1: Add support for mediated devices
>   vfio iommu: Add blocking notifier to notify DMA_UNMAP
>   vfio: Add notifier callback to parent's ops structure of mdev
>   vfio: Introduce common function to add capabilities
>   vfio_pci: Update vfio_pci to use vfio_info_add_capability()
>   vfio: Introduce vfio_set_irqs_validate_and_prepare()
>   vfio_pci: Updated to use vfio_set_irqs_validate_and_prepare()
>   vfio_platform: Updated to use vfio_set_irqs_validate_and_prepare()
>   vfio: Define device_api strings
>   docs: Add Documentation for Mediated devices
>   docs: Sysfs ABI for mediated device framework
>   docs: Sample driver to demonstrate how to use Mediated device
>     framework.
>   MAINTAINERS: Add entry VFIO based Mediated device drivers
> 
>  Documentation/ABI/testing/sysfs-bus-vfio-mdev |  111 ++
>  Documentation/vfio-mediated-device.txt        |  399 +++++++
>  MAINTAINERS                                   |    9 +
>  drivers/vfio/Kconfig                          |    1 +
>  drivers/vfio/Makefile                         |    1 +
>  drivers/vfio/mdev/Kconfig                     |   17 +
>  drivers/vfio/mdev/Makefile                    |    5 +
>  drivers/vfio/mdev/mdev_core.c                 |  388 +++++++
>  drivers/vfio/mdev/mdev_driver.c               |  122 ++
>  drivers/vfio/mdev/mdev_private.h              |   41 +
>  drivers/vfio/mdev/mdev_sysfs.c                |  286 +++++
>  drivers/vfio/mdev/vfio_mdev.c                 |  167 +++
>  drivers/vfio/pci/vfio_pci.c                   |   83 +-
>  drivers/vfio/platform/vfio_platform_common.c  |   31 +-
>  drivers/vfio/vfio.c                           |  334 +++++-
>  drivers/vfio/vfio_iommu_type1.c               |  831 ++++++++++++--
>  include/linux/mdev.h                          |  176 +++
>  include/linux/vfio.h                          |   32 +-
>  include/uapi/linux/vfio.h                     |   10 +
>  samples/vfio-mdev/Makefile                    |   13 +
>  samples/vfio-mdev/mtty.c                      | 1503 
> +++++++++++++++++++++++++
>  21 files changed, 4342 insertions(+), 218 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-vfio-mdev
>  create mode 100644 Documentation/vfio-mediated-device.txt
>  create mode 100644 drivers/vfio/mdev/Kconfig
>  create mode 100644 drivers/vfio/mdev/Makefile
>  create mode 100644 drivers/vfio/mdev/mdev_core.c
>  create mode 100644 drivers/vfio/mdev/mdev_driver.c
>  create mode 100644 drivers/vfio/mdev/mdev_private.h
>  create mode 100644 drivers/vfio/mdev/mdev_sysfs.c
>  create mode 100644 drivers/vfio/mdev/vfio_mdev.c
>  create mode 100644 include/linux/mdev.h
>  create mode 100644 samples/vfio-mdev/Makefile
>  create mode 100644 samples/vfio-mdev/mtty.c
> 


-- 
Alexey