Commit 1ae3a14f92 for qemu.org

commit 1ae3a14f92647390ab7a4bd4c46ac5bf853c3045
Author: Marc-André Lureau <marcandre.lureau@redhat.com>
Date:   Fri Aug 21 12:43:48 2026 +0400

    contrib/vhost-user-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/contrib/vhost-user-gpu/vhost-user-gpu.c b/contrib/vhost-user-gpu/vhost-user-gpu.c
index 933bdbb671..f70b34c179 100644
--- a/contrib/vhost-user-gpu/vhost-user-gpu.c
+++ b/contrib/vhost-user-gpu/vhost-user-gpu.c
@@ -36,7 +36,6 @@ struct virtio_gpu_simple_resource {
     uint32_t format;
     struct iovec *iov;
     unsigned int iov_cnt;
-    uint32_t scanout_bitmask;
     pixman_image_t *image;
     struct vugbm_buffer buffer;
     QTAILQ_ENTRY(virtio_gpu_simple_resource) next;
@@ -416,17 +415,12 @@ static void
 vg_disable_scanout(VuGpu *g, int scanout_id)
 {
     struct virtio_gpu_scanout *scanout = &g->scanout[scanout_id];
-    struct virtio_gpu_simple_resource *res;

     if (scanout->resource_id == 0) {
         return;
     }

-    res = virtio_gpu_find_resource(g, scanout->resource_id);
-    if (res) {
-        res->scanout_bitmask &= ~(1 << scanout_id);
-    }
-
+    scanout->resource_id = 0;
     scanout->width = 0;
     scanout->height = 0;

@@ -446,11 +440,9 @@ vg_resource_destroy(VuGpu *g,
 {
     int i;

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

@@ -662,7 +654,7 @@ static void
 vg_set_scanout(VuGpu *g,
                struct virtio_gpu_ctrl_command *cmd)
 {
-    struct virtio_gpu_simple_resource *res, *ores;
+    struct virtio_gpu_simple_resource *res;
     struct virtio_gpu_scanout *scanout;
     struct virtio_gpu_set_scanout ss;
     int fd;
@@ -707,12 +699,6 @@ vg_set_scanout(VuGpu *g,

     scanout = &g->scanout[ss.scanout_id];

-    ores = virtio_gpu_find_resource(g, scanout->resource_id);
-    if (ores) {
-        ores->scanout_bitmask &= ~(1 << ss.scanout_id);
-    }
-
-    res->scanout_bitmask |= (1 << ss.scanout_id);
     scanout->resource_id = ss.resource_id;
     scanout->x = ss.r.x;
     scanout->y = ss.r.y;
@@ -797,10 +783,10 @@ vg_resource_flush(VuGpu *g,
         pixman_region16_t region, finalregion;
         pixman_box16_t *extents;

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

         pixman_region_init(&finalregion);
         pixman_region_init_rect(&region, scanout->x, scanout->y,