Commit 9f1f607789 for qemu.org

commit 9f1f607789c61640a25eb73e6ff78b5012116845
Author: Marc-André Lureau <marcandre.lureau@redhat.com>
Date:   Sat Aug 22 15:55:05 2026 +0400

    virtio-gpu: drop scanout_bitmask bookkeeping

    The per-resource scanout_bitmask is a reverse index of which
    scanouts reference a given resource. The information is already
    available from scanout->resource_id. Performance impact should be
    negligible.

    Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
    Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index bcde65b503..6e021b78b8 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -434,12 +434,6 @@ static void virtio_gpu_release_scanout_dmabuf(VirtIOGPU *g, int scanout_id)
 void virtio_gpu_disable_scanout(VirtIOGPU *g, int scanout_id)
 {
     struct virtio_gpu_scanout *scanout = &g->parent_obj.scanout[scanout_id];
-    struct virtio_gpu_simple_resource *res;
-
-    res = virtio_gpu_find_resource(g, scanout->resource_id);
-    if (res) {
-        res->scanout_bitmask &= ~(1 << scanout_id);
-    }

     virtio_gpu_release_scanout_dmabuf(g, scanout_id);

@@ -456,11 +450,9 @@ static void virtio_gpu_resource_destroy(VirtIOGPU *g,
 {
     int i;

-    if (res->scanout_bitmask) {
-        for (i = 0; i < g->parent_obj.conf.max_outputs; i++) {
-            if (res->scanout_bitmask & (1 << i)) {
-                virtio_gpu_disable_scanout(g, i);
-            }
+    for (i = 0; i < g->parent_obj.conf.max_outputs; i++) {
+        if (g->parent_obj.scanout[i].resource_id == res->resource_id) {
+            virtio_gpu_disable_scanout(g, i);
         }
     }

@@ -639,10 +631,10 @@ static void virtio_gpu_resource_flush(VirtIOGPU *g,
     for (i = 0; i < g->parent_obj.conf.max_outputs; i++) {
         QemuRect rect;

-        if (!(res->scanout_bitmask & (1 << i))) {
+        scanout = &g->parent_obj.scanout[i];
+        if (scanout->resource_id != res->resource_id) {
             continue;
         }
-        scanout = &g->parent_obj.scanout[i];

         qemu_rect_init(&rect, scanout->x, scanout->y,
                        scanout->width, scanout->height);
@@ -667,16 +659,9 @@ void virtio_gpu_update_scanout(VirtIOGPU *g,
                                struct virtio_gpu_framebuffer *fb,
                                struct virtio_gpu_rect *r)
 {
-    struct virtio_gpu_simple_resource *ores;
     struct virtio_gpu_scanout *scanout;

     scanout = &g->parent_obj.scanout[scanout_id];
-    ores = virtio_gpu_find_resource(g, scanout->resource_id);
-    if (ores) {
-        ores->scanout_bitmask &= ~(1 << scanout_id);
-    }
-
-    res->scanout_bitmask |= (1 << scanout_id);
     scanout->resource_id = res->resource_id;
     scanout->x = r->x;
     scanout->y = r->y;
@@ -1707,7 +1692,6 @@ static int virtio_gpu_post_load(void *opaque, int version_id)
         if (scanout->cursor.resource_id) {
             update_cursor(g, &scanout->cursor);
         }
-        res->scanout_bitmask |= (1 << i);
     }

     return 0;
diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
index c2018b4105..071cbbb611 100644
--- a/include/hw/virtio/virtio-gpu.h
+++ b/include/hw/virtio/virtio-gpu.h
@@ -51,7 +51,6 @@ struct virtio_gpu_simple_resource {
     uint64_t *addrs;
     struct iovec *iov;
     unsigned int iov_cnt;
-    uint32_t scanout_bitmask;
     pixman_image_t *image;
     qemu_pixman_shareable share_handle;
     uint64_t hostmem;