On 20/2/25 10:50, Paolo Bonzini wrote:
On 2/20/25 10:20, Philippe Mathieu-Daudé wrote:
Hi,
QEMU provides the global '-g' CLI option:
$ qemu-system-foo --help
-g WxH[xDEPTH] Set the initial graphical resolution and depth
This option is used to pass resolution/depth information to guest
firmwares in the machines defined in the following files:
hw/ppc/mac_newworld.c
hw/ppc/mac_oldworld.c
hw/ppc/prep.c
hw/ppc/spapr.c
hw/sparc/sun4m.c
hw/sparc64/sun4u.c
Examples:
- hw/ppc/spapr.c:1102:
_FDT(fdt_setprop_cell(fdt, c, "qemu,graphic-width", graphic_width));
- hw/sparc64/sun4u.c:716:
fw_cfg_add_i16(fw_cfg, FW_CFG_SPARC64_WIDTH, graphic_width);
Obviously we have default values, which are different per architecture!
Clearly these ought to be machine properties.
Yes, we should have an easy way for machine to allow, in addition to -M
graphics=BOOLEAN, the structured property -M graphics.
{width,height,depth,enabled}. Then '-g' can desugar to -M
graphics.width=WW,graphics.height=HH,graphics.depth=BB.
It is also used to set TYPE_NUBUS_MACFB properties in hw/m68k/q800.c.
Here i suppose we could directly use '-global nubus-macfb.width=value'
etc. although I'm not sure it is the recommended way.
Should we start deprecating '-g' as a whole?
Only if it's unused/useless. If the option is useful it could also be
used for EDID, for example (adding Gerd).
Global variables are hard to track, and the one-off nature of the option
makes it hard to figure out (without looking at the code) which machine
support it.
However, if the properties were available and introspectable via QOM,
then it wouldn't matter if the -g sugar remains as an isolated "case
QEMU_OPTION_g:" in system/vl.c. For an example see -boot/-smp or -no-
reboot/-no-shutdown.
OK, I suppose you are pointing me to:
commit e6dba0481363ad343c5f984dd4de3dd06d79ee68
Author: Alejandro Jimenez <alejandro.j.jime...@oracle.com>
Date: Fri Dec 11 11:52:43 2020 -0500
qmp: generalize watchdog-set-action to -no-reboot/-no-shutdown
Add a QMP command to allow for the behaviors specified by the
-no-reboot and -no-shutdown command line option to be set at
runtime.
The new command is named set-action and takes optional arguments,
named after an event, that provide a corresponding action to take.
Commit 30e863e5a7a ("qapi/qom: Add ObjectOptions for input-*") already
introduced width/height notions in InputBarrierProperties:
# @width: the width of secondary screen in pixels (default: "1920")
#
# @height: the height of secondary screen in pixels (default: "1080")
Maybe we can extract a QAPI structure including depth.
Anyway I'll have a look, thanks for your guidance!
Phil.
