Hello,

This patchset adds toolstack support for I2C, GPIO and generic virtio devices.
This is inspired from the work done by Oleksandr for the Disk device.

This is developed as part of Linaro's Project Stratos, where we are working
towards Hypervisor agnostic Rust based backends [1].

This is based of Xen's master branch.

V8->V9:
- Drop changes to tools/ocaml/libs/xl/genwrap.py file.
- Replace GPIO with I2C in a comment.
- Add Reviewed-by tags.

V7->V8:
- Use macros for compatible string names.
- Use strcmp() instead of strncmp() at several places.
- Rename "virtio,devices" to "virtio,device" in commit log.
- Remove extra call to fdt_end_node().
- Disallow "unknown" in xenstore transport.
- Use libxl__strdup().
- Update documentation.
- Remove DEVICE_ADDREMOVE(virtio).

V6->V7:
- Support generic virtio devices too. They are passed with type=virtio,device,
  and we only create the MMIO DT node for them.
- Add links to DT bindings of I2C and GPIO, in code and documentation.
- Call libxl__device_add() for all hypervisor types.
- Add (0, "UNKNOWN") for libxl_virtio_transport.
- Removed libxl_virtio_backend and libxl_virtioinfo, as they were unused.
- Remove unnecessary stuff from libxl__virtio_from_xenstore() and add support
  for type and transport.
- Add backend=domid in documentation and replace compatible with type.
- Improved commit logs.

V5->V6:
- The cleanup patches are sent separately [2].
- We don't add I2C or GPIO specific device changes anymore, rather we create
  generic "virtio" devices. The "type" of a virtio devices helps us identify the
  right device, and create an entry in the DT node. The same can be used for all
  Virtio devices now.
- Update man page xl.cfg.

V4->V5:
- Fixed indentation at few places.
- Removed/added blank lines.
- Added few comments.
- Added review tags from Oleksandr.
- Rebased over latest staging branch.

V3->V4:
- Update virtio_enabled independently of all devices, so we don't miss setting
  it to true.

- Add iommu handling for i2c/gpio and move it as part of
  make_virtio_mmio_node_common(), which gets backend_domid parameter as a
  result.

V2->V3:
- Rebased over latest tree and made changes according to changes in Oleksandr's
  patches from sometime back.
- Minor cleanups.

V1->V2:
- Patches 3/6 and 4/6 are new.
- Patches 5/6 and 6/6 updated based on the above two patches.
- Added link to the bindings for I2C and GPIO.
- Rebased over latest master branch.


Thanks.

--
Viresh

[1] https://lore.kernel.org/xen-devel/20220414092358.kepxbmnrtycz7mhe@vireshk-i7/

Viresh Kumar (3):
  libxl: Add support for generic virtio device
  xl: Add support to parse generic virtio device
  docs: Add documentation for generic virtio devices

 docs/man/xl.cfg.5.pod.in                  |  33 +++++
 tools/libs/light/Makefile                 |   1 +
 tools/libs/light/libxl_arm.c              | 100 +++++++++++++++
 tools/libs/light/libxl_create.c           |   4 +
 tools/libs/light/libxl_internal.h         |   6 +
 tools/libs/light/libxl_types.idl          |  18 +++
 tools/libs/light/libxl_types_internal.idl |   1 +
 tools/libs/light/libxl_virtio.c           | 144 ++++++++++++++++++++++
 tools/xl/xl_parse.c                       |  81 ++++++++++++
 9 files changed, 388 insertions(+)
 create mode 100644 tools/libs/light/libxl_virtio.c

-- 
2.31.1.272.g89b43f80a514