[Qemu-devel] [PATCH] console: remove refresh timer when using spice & QXL mode

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

There is no need for the display refresh timer when using Spice with QXL
driver. The refresh is restored when entering VGA mode, or if any other
display listener requires refresh. This saves a few wakeups per seconds.

Related to:
https://bugzilla.redhat.com/show_bug.cgi?id=912763

Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
---
 hw/display/qxl.c     | 14 ++++++++++++++
 include/ui/console.h |  3 +++
 ui/console.c         | 23 ++++++++++++++++++++---
 3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index b540dd6..34a6334 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -1096,6 +1096,7 @@ static void qxl_enter_vga_mode(PCIQXLDevice *d)
     d->mode = QXL_MODE_VGA;
     vga_dirty_log_start(&d->vga);
     graphic_hw_update(d->vga.con);
+    update_displaystate(d->ssd.dcl.ds);
 }
 
 static void qxl_exit_vga_mode(PCIQXLDevice *d)
@@ -1107,6 +1108,7 @@ static void qxl_exit_vga_mode(PCIQXLDevice *d)
     graphic_console_set_hwops(d->ssd.dcl.con, &qxl_ops, d);
     vga_dirty_log_stop(&d->vga);
     qxl_destroy_primary(d, QXL_SYNC);
+    update_displaystate(d->ssd.dcl.ds);
 }
 
 static void qxl_update_irq(PCIQXLDevice *d)
@@ -1868,11 +1870,23 @@ static void display_refresh(DisplayChangeListener *dcl)
     }
 }
 
+static bool display_need_refresh(DisplayChangeListener *dcl)
+{
+    PCIQXLDevice *qxl = container_of(dcl, PCIQXLDevice, ssd.dcl);
+
+    if (qxl->mode == QXL_MODE_VGA) {
+        return true;
+    }
+
+    return false;
+}
+
 static DisplayChangeListenerOps display_listener_ops = {
     .dpy_name        = "spice/qxl",
     .dpy_gfx_update  = display_update,
     .dpy_gfx_switch  = display_switch,
     .dpy_refresh     = display_refresh,
+    .dpy_need_refresh = display_need_refresh,
 };
 
 static void qxl_init_ramsize(PCIQXLDevice *qxl)
diff --git a/include/ui/console.h b/include/ui/console.h
index 22ef8ca..cd0afc5 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -152,6 +152,8 @@ void cursor_get_mono_mask(QEMUCursor *c, int transparent, uint8_t *mask);
 typedef struct DisplayChangeListenerOps {
     const char *dpy_name;
 
+    bool (*dpy_need_refresh)(DisplayChangeListener *dcl);
+
     void (*dpy_refresh)(DisplayChangeListener *dcl);
 
     void (*dpy_gfx_update)(DisplayChangeListener *dcl,
@@ -185,6 +187,7 @@ struct DisplayChangeListener {
 };
 
 DisplayState *init_displaystate(void);
+void update_displaystate(DisplayState *ds);
 DisplaySurface *qemu_create_displaysurface_from(int width, int height,
                                                 pixman_format_code_t format,
                                                 int linesize, uint8_t *data);
diff --git a/ui/console.c b/ui/console.c
index 258af5d..9815667 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -180,6 +180,7 @@ static QEMUTimer *cursor_timer;
 
 static void text_console_do_init(CharDriverState *chr, DisplayState *ds);
 static void dpy_refresh(DisplayState *s);
+static bool dpy_need_refresh(DisplayState *s);
 static DisplayState *get_alloc_displaystate(void);
 static void text_console_update_cursor_timer(void);
 static void text_console_update_cursor(void *opaque);
@@ -216,7 +217,7 @@ static void gui_update(void *opaque)
     timer_mod(ds->gui_timer, ds->last_update + interval);
 }
 
-static void gui_setup_refresh(DisplayState *ds)
+void update_displaystate(DisplayState *ds)
 {
     DisplayChangeListener *dcl;
     bool need_timer = false;
@@ -235,6 +236,8 @@ static void gui_setup_refresh(DisplayState *ds)
         }
     }
 
+    need_timer &= dpy_need_refresh(ds);
+
     if (need_timer && ds->gui_timer == NULL) {
         ds->gui_timer = timer_new_ms(QEMU_CLOCK_REALTIME, gui_update, ds);
         timer_mod(ds->gui_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
@@ -1341,7 +1344,7 @@ void register_displaychangelistener(DisplayChangeListener *dcl)
     trace_displaychangelistener_register(dcl, dcl->ops->dpy_name);
     dcl->ds = get_alloc_displaystate();
     QLIST_INSERT_HEAD(&dcl->ds->listeners, dcl, next);
-    gui_setup_refresh(dcl->ds);
+    update_displaystate(dcl->ds);
     if (dcl->con) {
         dcl->con->dcls++;
         con = dcl->con;
@@ -1380,7 +1383,7 @@ void unregister_displaychangelistener(DisplayChangeListener *dcl)
         dcl->con->dcls--;
     }
     QLIST_REMOVE(dcl, next);
-    gui_setup_refresh(ds);
+    update_displaystate(ds);
 }
 
 int dpy_set_ui_info(QemuConsole *con, QemuUIInfo *info)
@@ -1450,6 +1453,20 @@ static void dpy_refresh(DisplayState *s)
     }
 }
 
+static bool dpy_need_refresh(DisplayState *s)
+{
+    DisplayChangeListener *dcl;
+
+    QLIST_FOREACH(dcl, &s->listeners, next) {
+        if (!dcl->ops->dpy_need_refresh ||
+            dcl->ops->dpy_need_refresh(dcl)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 void dpy_gfx_copy(QemuConsole *con, int src_x, int src_y,
                   int dst_x, int dst_y, int w, int h)
 {
-- 
1.9.3