Re: [PATCH v11 00/22] Add Mediated device support
From: Alexey Kardashevskiy
Date: Sun Nov 06 2016 - 22:46:21 EST
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