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

[Kirti Wankhede]

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:
  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

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2.7.0