mbox series

[RFC,v4,0/7] pds vfio driver

Message ID 20230308052450.13421-1-brett.creeley@amd.com (mailing list archive)
Headers show
Series pds vfio driver | expand

Message

Brett Creeley March 8, 2023, 5:24 a.m. UTC 
This is a draft patchset for a new vendor specific VFIO driver
(pds_vfio) for use with the AMD/Pensando Distributed Services Card
(DSC). This driver is a client of the newly introduced pds_core
driver, which the latest version can be referenced at:

https://lore.kernel.org/netdev/20230308051310.12544-1-shannon.nelson@amd.com/

This driver will use the pds_core device's adminq as the VFIO
control path to the DSC. In order to make adminq calls, the VFIO
instance makes use of functions exported by the pds_core driver.

In order to receive events from pds_core, the pds_vfio driver
registers to a private notifier. This is needed for various events
that come from the device.

An ASCII diagram of a VFIO instance looks something like this and can
be used with the VFIO subsystem to provide the VF device VFIO and live
migration support.

                               .------.  .-----------------------.
                               | QEMU |--|  VM  .-------------.  |
                               '......'  |      |   Eth VF    |  |
                                  |      |      .-------------.  |
                                  |      |      |  SR-IOV VF  |  |
                                  |      |      '-------------'  |
                                  |      '------------||---------'
                               .--------------.       ||
                               |/dev/<vfio_fd>|       ||
                               '--------------'       ||
Host Userspace                         |              ||
===================================================   ||
Host Kernel                            |              ||
                                  .--------.          ||
                                  |vfio-pci|          ||
                                  '--------'          ||
       .------------------.           ||              ||
       |   | EXPORTed API |<----+     ||              ||
       |   '--------------|     |     ||              ||
       |                  |    .-------------.        ||
       |     pds_core     |--->|   pds_vfio  |        ||
       '------------------' |  '-------------'        ||
               ||           |         ||              ||
             09:00.0     notifier    09:00.1          ||
== PCI ===============================================||=====
               ||                     ||              ||
          .----------.          .----------.          ||
    ,-----|    PF    |----------|    VF    |-------------------,
    |     '----------'          '----------'  |       VF       |
    |                     DSC                 |  data/control  |
    |                                         |      path      |
    -----------------------------------------------------------


The pds_vfio driver is targeted to reside in drivers/vfio/pci/pds.
It makes use of and introduces new files in the common include/linux/pds
include directory.

Changes:
v4:
- Update cover letter ASCII diagram to reflect new driver architecture
- Remove auxiliary driver implementation
- Use pds_core's exported functions to communicate with the device
- Implement and register notifier for events from the device/pds_core
- Use module_pci_driver() macro since auxiliary driver configuration is
  no longer needed in __init/__exit

v3:
https://lore.kernel.org/netdev/20230219083908.40013-1-brett.creeley@amd.com/
- Update copyright year to 2023 and use "Advanced Micro Devices, Inc."
  for the company name
- Clarify the fact that AMD/Pensando's VFIO solution is device type
  agnostic, which aligns with other current VFIO solutions
- Add line in drivers/vfio/pci/Makefile to build pds_vfio
- Move documentation to amd sub-directory
- Remove some dead code due to the pds_core implementation of
  listening to BIND/UNBIND events
- Move a dev_dbg() to a previous patch in the series
- Add implementation for vfio_migration_ops.migration_get_data_size to
  return the maximum possible device state size

RFC to v2:
https://lore.kernel.org/all/20221214232136.64220-1-brett.creeley@amd.com/
- Implement state transitions for VFIO_MIGRATION_P2P flag
- Improve auxiliary driver probe by returning EPROBE_DEFER
  when the PCI driver is not set up correctly
- Add pointer to docs in
  Documentation/networking/device_drivers/ethernet/index.rst

RFC:
https://lore.kernel.org/all/20221207010705.35128-1-brett.creeley@amd.com/

Brett Creeley (7):
  vfio: Commonize combine_ranges for use in other VFIO drivers
  vfio/pds: Initial support for pds_vfio VFIO driver
  vfio/pds: register with the pds_core PF
  vfio/pds: Add VFIO live migration support
  vfio/pds: Add support for dirty page tracking
  vfio/pds: Add support for firmware recovery
  vfio/pds: Add Kconfig and documentation

 .../device_drivers/ethernet/amd/pds_vfio.rst  |  79 +++
 .../device_drivers/ethernet/index.rst         |   1 +
 MAINTAINERS                                   |   7 +
 drivers/vfio/pci/Kconfig                      |   2 +
 drivers/vfio/pci/Makefile                     |   2 +
 drivers/vfio/pci/mlx5/cmd.c                   |  48 +-
 drivers/vfio/pci/pds/Kconfig                  |  20 +
 drivers/vfio/pci/pds/Makefile                 |  11 +
 drivers/vfio/pci/pds/cmds.c                   | 527 +++++++++++++++++
 drivers/vfio/pci/pds/cmds.h                   |  27 +
 drivers/vfio/pci/pds/dirty.c                  | 540 ++++++++++++++++++
 drivers/vfio/pci/pds/dirty.h                  |  45 ++
 drivers/vfio/pci/pds/lm.c                     | 486 ++++++++++++++++
 drivers/vfio/pci/pds/lm.h                     |  52 ++
 drivers/vfio/pci/pds/pci_drv.c                | 210 +++++++
 drivers/vfio/pci/pds/pci_drv.h                |   9 +
 drivers/vfio/pci/pds/vfio_dev.c               | 235 ++++++++
 drivers/vfio/pci/pds/vfio_dev.h               |  40 ++
 drivers/vfio/vfio_main.c                      |  48 ++
 include/linux/pds/pds_lm.h                    | 391 +++++++++++++
 include/linux/vfio.h                          |   3 +
 21 files changed, 2736 insertions(+), 47 deletions(-)
 create mode 100644 Documentation/networking/device_drivers/ethernet/amd/pds_vfio.rst
 create mode 100644 drivers/vfio/pci/pds/Kconfig
 create mode 100644 drivers/vfio/pci/pds/Makefile
 create mode 100644 drivers/vfio/pci/pds/cmds.c
 create mode 100644 drivers/vfio/pci/pds/cmds.h
 create mode 100644 drivers/vfio/pci/pds/dirty.c
 create mode 100644 drivers/vfio/pci/pds/dirty.h
 create mode 100644 drivers/vfio/pci/pds/lm.c
 create mode 100644 drivers/vfio/pci/pds/lm.h
 create mode 100644 drivers/vfio/pci/pds/pci_drv.c
 create mode 100644 drivers/vfio/pci/pds/pci_drv.h
 create mode 100644 drivers/vfio/pci/pds/vfio_dev.c
 create mode 100644 drivers/vfio/pci/pds/vfio_dev.h
 create mode 100644 include/linux/pds/pds_lm.h