void qxl_render_update(PCIQXLDevice *qxl)
{
    VGACommonState *vga = &qxl->vga;
    QXLRect dirty[32], update;
    void *ptr;
    int i;

    if (qxl->guest_primary.resized) {
        qxl->guest_primary.resized = 0;

        if (qxl->guest_primary.flipped) {
            qemu_free(qxl->guest_primary.flipped);
            qxl->guest_primary.flipped = NULL;
        }
        qemu_free_displaysurface(vga->ds);

        qxl->guest_primary.data = qemu_get_ram_ptr(qxl->vga.vram_offset);
        if (qxl->guest_primary.stride < 0) {
            /* spice surface is upside down -> need extra buffer to flip */
            qxl->guest_primary.stride = -qxl->guest_primary.stride;
            qxl->guest_primary.flipped = qemu_malloc(qxl->guest_primary.surface.width *
                                                     qxl->guest_primary.stride);
            ptr = qxl->guest_primary.flipped;
        } else {
            ptr = qxl->guest_primary.data;
        }
        dprint(qxl, 1, "%s: %dx%d, stride %d, bpp %d, depth %d, flip %s\n",
               __FUNCTION__,
               qxl->guest_primary.surface.width,
               qxl->guest_primary.surface.height,
               qxl->guest_primary.stride,
               qxl->guest_primary.bytes_pp,
               qxl->guest_primary.bits_pp,
               qxl->guest_primary.flipped ? "yes" : "no");
        vga->ds->surface =
            qemu_create_displaysurface_from(qxl->guest_primary.surface.width,
                                            qxl->guest_primary.surface.height,
                                            qxl->guest_primary.bits_pp,
                                            qxl->guest_primary.stride,
                                            ptr);
        dpy_resize(vga->ds);
    }

    if (!qxl->guest_primary.commands) {
        return;
    }
    qxl->guest_primary.commands = 0;

    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));
    qxl_spice_update_area(qxl, 0, &update,
                          dirty, ARRAY_SIZE(dirty), 1, QXL_SYNC);

    for (i = 0; i < ARRAY_SIZE(dirty); i++) {
        if (qemu_spice_rect_is_empty(dirty+i)) {
            break;
        }
        if (qxl->guest_primary.flipped) {
            qxl_flip(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);
    }
}
void qxl_render_update(PCIQXLDevice *qxl)
{
    VGACommonState *vga = &qxl->vga;
    QXLRect dirty[32], update;
    void *ptr;
    int i;

    if (qxl->guest_primary.resized) {
        qxl->guest_primary.resized = 0;

        if (qxl->guest_primary.flipped) {
            qemu_free(qxl->guest_primary.flipped);
            qxl->guest_primary.flipped = NULL;
        }
        qemu_free_displaysurface(vga->ds);

        qxl->guest_primary.data = qemu_get_ram_ptr(qxl->vga.vram_offset);
        if (qxl->guest_primary.stride < 0) {
             
            qxl->guest_primary.stride = -qxl->guest_primary.stride;
            qxl->guest_primary.flipped = qemu_malloc(qxl->guest_primary.surface.width *
                                                     qxl->guest_primary.stride);
            ptr = qxl->guest_primary.flipped;
        } else {
            ptr = qxl->guest_primary.data;
        }
        dprint(qxl, 1, "%s: %dx%d, stride %d, bpp %d, depth %d, flip %s\n",
               __FUNCTION__,
               qxl->guest_primary.surface.width,
               qxl->guest_primary.surface.height,
               qxl->guest_primary.stride,
               qxl->guest_primary.bytes_pp,
               qxl->guest_primary.bits_pp,
               qxl->guest_primary.flipped ? "yes" : "no");
        vga->ds->surface =
            qemu_create_displaysurface_from(qxl->guest_primary.surface.width,
                                            qxl->guest_primary.surface.height,
                                            qxl->guest_primary.bits_pp,
                                            qxl->guest_primary.stride,
                                            ptr);
        dpy_resize(vga->ds);
    }

    if (!qxl->guest_primary.commands) {
        return;
    }
    qxl->guest_primary.commands = 0;

    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));
    qxl_spice_update_area(qxl, 0, &update,
                          dirty, ARRAY_SIZE(dirty), 1, QXL_SYNC);

    for (i = 0; i < ARRAY_SIZE(dirty); i++) {
        if (qemu_spice_rect_is_empty(dirty+i)) {
            break;
        }
        if (qxl->guest_primary.flipped) {
            qxl_flip(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);
    }
}