[PATCH 0/2] Introduce printer subsystem and USB printer device

[Ruien Zhang <zhangruien@bytedance.com>]

From: zhangruien <zhangruien@bytedance.com>

Currently, printer support in QEMU can generally be considered with these
approaches:

1) USB passthrough & redirection, with the limitation of flexibility and
   transport-specific issues that come along with.

2) Network reachability with network printers, which is also driver-specific,
   thus less friendly to small systems.

Driverless Printing [1] may or may not be network-dependent, the former is the
general case while the latter imposes less restraints on cloud environments, and
it doesn't necessarily mean that we have to follow the methods in 1) to achieve
this. Transport protocols targeted at devices such as USB printer class [2] with
the extension of IPP-over-USB [3] and many others can be integrated into QEMU,
presenting more flexibility and functionality.

This patchset introduces:

1) Skeleton of QEMU printer subsystem with a dummy builtin driver.

2) USB printer device emulation, with definitions in the extension of IPP-over-
   USB [3].

WIP:

1) QEMU printer subsystem interfaces, which will be finalized with a concrete
   backend driver.

2) IPP-over-USB implementation.

[1]: https://openprinting.github.io/driverless
[2]: https://www.usb.org/sites/default/files/usbprint11a021811.pdf
[3]: https://www.usb.org/document-library/ipp-protocol-10

zhangruien (2):
  printer: Introduce printer subsystem
  usb-printer: Introduce USB printer class

 MAINTAINERS                 |   7 +
 docs/system/devices/usb.rst |   3 +
 hw/usb/Kconfig              |   5 +
 hw/usb/dev-printer.c        | 423 ++++++++++++++++++++++++++++++++++++++++++++
 hw/usb/meson.build          |   1 +
 hw/usb/trace-events         |  11 ++
 include/hw/usb/printer.h    |  93 ++++++++++
 include/printer/printer.h   |  42 +++++
 meson.build                 |  12 +-
 meson_options.txt           |   3 +
 printer/builtin.c           |  61 +++++++
 printer/meson.build         |  14 ++
 printer/printer.c           | 191 ++++++++++++++++++++
 printer/trace-events        |   5 +
 printer/trace.h             |   1 +
 qapi/meson.build            |   1 +
 qapi/printer.json           |  47 +++++
 qapi/qapi-schema.json       |   1 +
 qemu-options.hx             |   8 +
 softmmu/vl.c                |   4 +
 20 files changed, 932 insertions(+), 1 deletion(-)
 create mode 100644 hw/usb/dev-printer.c
 create mode 100644 include/hw/usb/printer.h
 create mode 100644 include/printer/printer.h
 create mode 100644 printer/builtin.c
 create mode 100644 printer/meson.build
 create mode 100644 printer/printer.c
 create mode 100644 printer/trace-events
 create mode 100644 printer/trace.h
 create mode 100644 qapi/printer.json

-- 
2.11.0