From c388f408b538b38db83999fd20b17020d5fdf68f Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Wed, 8 Jan 2020 15:47:02 +0100
Subject: [PATCH 1/2] ui: Print available display backends with '-display help'
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We already print availabled devices with "-device help", or available
backends with "-netdev help" or "-chardev help". Let's provide a way
for the users to query the available display backends, too.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-id: 20200108144702.29969-1-thuth@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
include/ui/console.h | 1 +
qemu-options.hx | 3 ++-
ui/console.c | 15 +++++++++++++++
vl.c | 5 +++++
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/include/ui/console.h b/include/ui/console.h
index 281f9c145b..f35b4fc082 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -442,6 +442,7 @@ void qemu_display_register(QemuDisplay *ui);
bool qemu_display_find_default(DisplayOptions *opts);
void qemu_display_early_init(DisplayOptions *opts);
void qemu_display_init(DisplayState *ds, DisplayOptions *opts);
+void qemu_display_help(void);
/* vnc.c */
void vnc_display_init(const char *id, Error **errp);
diff --git a/qemu-options.hx b/qemu-options.hx
index d4b73ef60c..709162c159 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1669,7 +1669,8 @@ STEXI
@item -display @var{type}
@findex -display
Select type of display to use. This option is a replacement for the
-old style -sdl/-curses/... options. Valid values for @var{type} are
+old style -sdl/-curses/... options. Use @code{-display help} to list
+the available display types. Valid values for @var{type} are
@table @option
@item sdl
Display video output via SDL (usually in a separate graphics
diff --git a/ui/console.c b/ui/console.c
index ac79d679f5..69339b028b 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -2333,6 +2333,21 @@ void qemu_display_init(DisplayState *ds, DisplayOptions *opts)
dpys[opts->type]->init(ds, opts);
}
+void qemu_display_help(void)
+{
+ int idx;
+
+ printf("Available display backend types:\n");
+ for (idx = DISPLAY_TYPE_NONE; idx < DISPLAY_TYPE__MAX; idx++) {
+ if (!dpys[idx]) {
+ ui_module_load_one(DisplayType_str(idx));
+ }
+ if (dpys[idx]) {
+ printf("%s\n", DisplayType_str(dpys[idx]->type));
+ }
+ }
+}
+
void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp)
{
int val;
diff --git a/vl.c b/vl.c
index 158a05ed32..751401214c 100644
--- a/vl.c
+++ b/vl.c
@@ -1869,6 +1869,11 @@ static void parse_display(const char *p)
{
const char *opts;
+ if (is_help_option(p)) {
+ qemu_display_help();
+ exit(0);
+ }
+
if (strstart(p, "sdl", &opts)) {
/*
* sdl DisplayType needs hand-crafted parser instead of
From c4c00922cc948bb5e879bfae60764eba1f8745f3 Mon Sep 17 00:00:00 2001
From: Nikola Pavlica <pavlica.nikola@gmail.com>
Date: Wed, 8 Jan 2020 13:13:42 +0100
Subject: [PATCH 2/2] display/gtk: get proper refreshrate
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Because some VMs in QEMU can get GPU virtualization (using technologies
such as iGVT-g, as mentioned previously), they could produce a video
output that had a higher display refresh rate than of what the GTK
display was displaying. (fxp. Playing a video game inside of a Windows
VM at 60 Hz, while the output stood locked at 33 Hz because of defaults
set in include/ui/console.h)
Since QEMU does indeed have internal systems for determining frame
times as defined in ui/console.c.
The code checks for a variable called update_interval that it later
uses for time calculation. This variable, however, isn't defined
anywhere in ui/gtk.c and instead ui/console.c just sets it to
GUI_REFRESH_INTERVAL_DEFAULT which is 30
update_interval represents the number of milliseconds per display
refresh, and by doing some math we get that 1000/30 = 33.33... Hz
This creates the mentioned problem and what this patch does is that it
checks for the display refresh rate reported by GTK itself (we can take
this as a safe value) and just converts it back to a number of
milliseconds per display refresh.
Signed-off-by: Nikola Pavlica <pavlica.nikola@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200108121342.29597-1-pavlica.nikola@gmail.com
[ kraxel: style tweak: add blank line between vars and code ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
include/ui/gtk.h | 2 ++
ui/gtk.c | 11 +++++++++++
2 files changed, 13 insertions(+)
diff --git a/include/ui/gtk.h b/include/ui/gtk.h
index d9eedad976..d1b230848a 100644
--- a/include/ui/gtk.h
+++ b/include/ui/gtk.h
@@ -28,6 +28,8 @@
#include "ui/egl-context.h"
#endif
+#define MILLISEC_PER_SEC 1000000
+
typedef struct GtkDisplayState GtkDisplayState;
typedef struct VirtualGfxConsole {
diff --git a/ui/gtk.c b/ui/gtk.c
index 692ccc7bbb..7355d34fcf 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1966,6 +1966,11 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
GSList *group, GtkWidget *view_menu)
{
bool zoom_to_fit = false;
+ int refresh_rate_millihz;
+
+ GdkDisplay *dpy = gtk_widget_get_display(s->window);
+ GdkWindow *win = gtk_widget_get_window(s->window);
+ GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win);
vc->label = qemu_console_get_label(con);
vc->s = s;
@@ -2026,6 +2031,12 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
vc->gfx.kbd = qkbd_state_init(con);
vc->gfx.dcl.con = con;
+
+ refresh_rate_millihz = gdk_monitor_get_refresh_rate(monitor);
+ if (refresh_rate_millihz) {
+ vc->gfx.dcl.update_interval = MILLISEC_PER_SEC / refresh_rate_millihz;
+ }
+
register_displaychangelistener(&vc->gfx.dcl);
gd_connect_vc_gfx_signals(vc);