qxl: make qxl_render_update async

RHBZ# 747011

Removes the last user of QXL_SYNC when using update drivers that use the
_ASYNC io ports.

The last user is qxl_render_update, it is called both by qxl_hw_update
which is the vga_hw_update_ptr passed to graphic_console_init, and by
qxl_hw_screen_dump.

At the same time the QXLRect area being passed to the red_worker thread
is passed as a copy, as part of the QXLCookie.

The implementation uses interface_update_area_complete with a bh to make
sure dpy_update and qxl_flip are called from the io thread, otherwise
the vga->ds->surface.data can change under our feet.

With this patch sdl+spice works fine. But spice by itself doesn't
produce the expected screendumps unless repeated a few times, due to
ppm_save being called before update_area (rendering done in spice server
thread) having a chance to complete. Fixed by next patch, but see commit
message for problem introduced by it.

Signed-off-by: Alon Levy <alevy@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 69 insertions, 27 deletions

diff --git a/hw/qxl-render.c b/hw/qxl-render.c
index c45dc30ab3..f323a4df68 100644
--- a/hw/qxl-render.c
+++ b/hw/qxl-render.c
@@ -82,17 +82,25 @@ void qxl_render_resize(PCIQXLDevice *qxl)
     }
 }
 
-void qxl_render_update(PCIQXLDevice *qxl)
+static void qxl_set_rect_to_surface(PCIQXLDevice *qxl, QXLRect *area)
+{
+    area->left   = 0;
+    area->right  = qxl->guest_primary.surface.width;
+    area->top    = 0;
+    area->bottom = qxl->guest_primary.surface.height;
+}
+
+static void qxl_render_update_area_unlocked(PCIQXLDevice *qxl)
 {
     VGACommonState *vga = &qxl->vga;
-    QXLRect dirty[32], update;
-    int i, redraw = 0;
+    int i;
     DisplaySurface *surface = vga->ds->surface;
 
     if (qxl->guest_primary.resized) {
         qxl->guest_primary.resized = 0;
-
         qxl->guest_primary.data = memory_region_get_ram_ptr(&qxl->vga.vram);
+        qxl_set_rect_to_surface(qxl, &qxl->dirty[0]);
+        qxl->num_dirty_rects = 1;
         dprint(qxl, 1, "%s: %dx%d, stride %d, bpp %d, depth %d\n",
                __FUNCTION__,
                qxl->guest_primary.surface.width,
@@ -103,9 +111,9 @@ void qxl_render_update(PCIQXLDevice *qxl)
     }
     if (surface->width != qxl->guest_primary.surface.width ||
         surface->height != qxl->guest_primary.surface.height) {
-        dprint(qxl, 1, "%s: resizing displaysurface to guest_primary\n",
-               __func__);
         if (qxl->guest_primary.qxl_stride > 0) {
+            dprint(qxl, 1, "%s: using guest_primary for displaysurface\n",
+                   __func__);
             qemu_free_displaysurface(vga->ds);
             qemu_create_displaysurface_from(qxl->guest_primary.surface.width,
                                             qxl->guest_primary.surface.height,
@@ -113,36 +121,70 @@ void qxl_render_update(PCIQXLDevice *qxl)
                                             qxl->guest_primary.abs_stride,
                                             qxl->guest_primary.data);
         } else {
+            dprint(qxl, 1, "%s: resizing displaysurface to guest_primary\n",
+                   __func__);
             qemu_resize_displaysurface(vga->ds,
                     qxl->guest_primary.surface.width,
                     qxl->guest_primary.surface.height);
         }
     }
-    update.left   = 0;
-    update.right  = qxl->guest_primary.surface.width;
-    update.top    = 0;
-    update.bottom = qxl->guest_primary.surface.height;
-
-    memset(dirty, 0, sizeof(dirty));
-    if (runstate_is_running() && qxl->guest_primary.commands) {
-        qxl->guest_primary.commands = 0;
-        qxl_spice_update_area(qxl, 0, &update,
-                              dirty, ARRAY_SIZE(dirty), 1, QXL_SYNC, NULL);
-    }
-    if (redraw) {
-        memset(dirty, 0, sizeof(dirty));
-        dirty[0] = update;
-    }
-    for (i = 0; i < ARRAY_SIZE(dirty); i++) {
-        if (qemu_spice_rect_is_empty(dirty+i)) {
+    for (i = 0; i < qxl->num_dirty_rects; i++) {
+        if (qemu_spice_rect_is_empty(qxl->dirty+i)) {
             break;
         }
-        qxl_flip(qxl, dirty+i);
+        qxl_flip(qxl, qxl->dirty+i);
         dpy_update(vga->ds,
-                   dirty[i].left, dirty[i].top,
-                   dirty[i].right - dirty[i].left,
-                   dirty[i].bottom - dirty[i].top);
+                   qxl->dirty[i].left, qxl->dirty[i].top,
+                   qxl->dirty[i].right - qxl->dirty[i].left,
+                   qxl->dirty[i].bottom - qxl->dirty[i].top);
+    }
+    qxl->num_dirty_rects = 0;
+}
+
+/*
+ * use ssd.lock to protect render_update_cookie_num.
+ * qxl_render_update is called by io thread or vcpu thread, and the completion
+ * callbacks are called by spice_server thread, defering to bh called from the
+ * io thread.
+ */
+void qxl_render_update(PCIQXLDevice *qxl)
+{
+    QXLCookie *cookie;
+
+    qemu_mutex_lock(&qxl->ssd.lock);
+
+    if (!runstate_is_running() || !qxl->guest_primary.commands) {
+        qxl_render_update_area_unlocked(qxl);
+        qemu_mutex_unlock(&qxl->ssd.lock);
+        return;
     }
+
+    qxl->guest_primary.commands = 0;
+    qxl->render_update_cookie_num++;
+    qemu_mutex_unlock(&qxl->ssd.lock);
+    cookie = qxl_cookie_new(QXL_COOKIE_TYPE_RENDER_UPDATE_AREA,
+                            0);
+    qxl_set_rect_to_surface(qxl, &cookie->u.render.area);
+    qxl_spice_update_area(qxl, 0, &cookie->u.render.area, NULL,
+                          0, 1 /* clear_dirty_region */, QXL_ASYNC, cookie);
+}
+
+void qxl_render_update_area_bh(void *opaque)
+{
+    PCIQXLDevice *qxl = opaque;
+
+    qemu_mutex_lock(&qxl->ssd.lock);
+    qxl_render_update_area_unlocked(qxl);
+    qemu_mutex_unlock(&qxl->ssd.lock);
+}
+
+void qxl_render_update_area_done(PCIQXLDevice *qxl, QXLCookie *cookie)
+{
+    qemu_mutex_lock(&qxl->ssd.lock);
+    qemu_bh_schedule(qxl->update_area_bh);
+    qxl->render_update_cookie_num--;
+    qemu_mutex_unlock(&qxl->ssd.lock);
+    g_free(cookie);
 }
 
 static QEMUCursor *qxl_cursor(PCIQXLDevice *qxl, QXLCursor *cursor)