Re: [PATCH v11 00/22] Add Mediated device support
From: Kirti Wankhede
Date: Sun Nov 06 2016 - 22:59:55 EST
On 11/7/2016 9:00 AM, Alexey Kardashevskiy wrote:
> 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.
>
>
Pull commit 05692d7005a3 (below) commit.
>
>> 05692d7005a3 vfio/pci: Fix integer overflows, bitmask check
>>
Thanks,
Kirti
>>
>> 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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