Re: [PATCH v5 00/19] Make Pixman an optional dependency

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Oct 23, 2023 at 03:30:27PM +0400, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> Hi,
> 
> QEMU system emulators can be made to compile and work without Pixman.
> 
> Only a few devices and options actually require it (VNC, Gtk, Spice for ex) and
> will have to be compiled out.
> 
> However, most of QEMU graphics-related code is based on pixman_image_t and
> format. If we want to provide mostly compatible QEMU machines with or without
> Pixman, all we need to do is to have a small compatibility header with just the
> bare minimum for those types (see "ui: add pixman-compat.h"). There are a
> limited number of operations related to geometry that are slightly better
> implemented in QEMU (without Pixman, see "virtio-gpu: replace PIXMAN for
> region/rect test").
> 
> Without this simple compatibility header approach, QEMU at runtime becomes a
> very different emulator (without graphics device/board, display etc) and full of
> "if PIXMAN" conditions in the code. This is a much worse outcome imho, compared
> to this small header maintainance and compatibility story.
> 
> Fixes:
> https://gitlab.com/qemu-project/qemu/-/issues/1172


virtio things:

Acked-by: Michael S. Tsirkin <mst@redhat.com>


> v5:
> - fixed "vl: move display early init before default devices" patch
> 
> v4:
> - added "vl: move display early init before default devices" patch
> - code style fixes
> - a-b from Zoltan
> 
> v3:
> - improve transient meson condition in first patch (Paolo)
> - use muxed console as fallback by default (Paolo)
> - make pixman-compat.h closer to original API
> - keep "x-pixman" property for sm501 (Zoltan)
> 
> Marc-André Lureau (19):
>   build-sys: add a "pixman" feature
>   ui: compile out some qemu-pixman functions when !PIXMAN
>   ui: add pixman-compat.h
>   vl: move display early init before default devices
>   ui/console: allow to override the default VC
>   ui/vc: console-vc requires PIXMAN
>   qmp/hmp: disable screendump if PIXMAN is missing
>   virtio-gpu: replace PIXMAN for region/rect test
>   ui/console: when PIXMAN is unavailable, don't draw placeholder msg
>   vhost-user-gpu: skip VHOST_USER_GPU_UPDATE when !PIXMAN
>   ui/gl: opengl doesn't require PIXMAN
>   ui/vnc: VNC requires PIXMAN
>   ui/spice: SPICE/QXL requires PIXMAN
>   ui/gtk: -display gtk requires PIXMAN
>   ui/dbus: do not require PIXMAN
>   arm/kconfig: XLNX_ZYNQMP_ARM depends on PIXMAN
>   hw/sm501: allow compiling without PIXMAN
>   hw/display: make ATI_VGA depend on PIXMAN
>   build-sys: make pixman actually optional
> 
>  configs/devices/mips64el-softmmu/default.mak |   2 +-
>  meson.build                                  |  25 ++-
>  qapi/ui.json                                 |   3 +-
>  include/ui/console.h                         |   2 +
>  include/ui/pixman-compat.h                   | 195 +++++++++++++++++++
>  include/ui/qemu-pixman.h                     |  11 +-
>  include/ui/rect.h                            |  59 ++++++
>  hw/display/sm501.c                           |  59 ++++--
>  hw/display/vhost-user-gpu.c                  |   2 +
>  hw/display/virtio-gpu.c                      |  30 ++-
>  system/vl.c                                  |  68 ++++---
>  ui/console-vc-stubs.c                        |  33 ++++
>  ui/console.c                                 |  19 ++
>  ui/dbus-listener.c                           |  90 ++++++---
>  ui/qemu-pixman.c                             |   6 +
>  ui/ui-hmp-cmds.c                             |   2 +
>  ui/ui-qmp-cmds.c                             |   2 +
>  Kconfig.host                                 |   3 +
>  hmp-commands.hx                              |   2 +
>  hw/arm/Kconfig                               |   3 +-
>  hw/display/Kconfig                           |   9 +-
>  hw/display/meson.build                       |   4 +-
>  meson_options.txt                            |   2 +
>  scripts/meson-buildoptions.sh                |   3 +
>  ui/meson.build                               |  24 +--
>  25 files changed, 541 insertions(+), 117 deletions(-)
>  create mode 100644 include/ui/pixman-compat.h
>  create mode 100644 include/ui/rect.h
>  create mode 100644 ui/console-vc-stubs.c
> 
> -- 
> 2.41.0