ui/console: Use qemu_dmabuf_new() and free() helpers instead

This commit introduces utility functions for the creation and deallocation
of QemuDmaBuf instances. Additionally, it updates all relevant sections
of the codebase to utilize these new utility functions.

v7: remove prefix, "dpy_gl_" from all helpers
    qemu_dmabuf_free() returns without doing anything if input is null
    (Daniel P. Berrangé <berrange@redhat.com>)
    call G_DEFINE_AUTOPTR_CLEANUP_FUNC for qemu_dmabuf_free()
    (Daniel P. Berrangé <berrange@redhat.com>)

v8: Introduction of helpers was removed as those were already added
    by the previous commit

v9: set dmabuf->allow_fences to 'true' when dmabuf is created in
    virtio_gpu_create_dmabuf()/virtio-gpu-udmabuf.c

    removed unnecessary spaces were accidently added in the patch,
    'ui/console: Use qemu_dmabuf_new() a...'

v11: Calling qemu_dmabuf_close was removed as closing dmabuf->fd will be
     done in qemu_dmabuf_free anyway.
     (Daniel P. Berrangé <berrange@redhat.com>)

v12: --- Calling qemu_dmabuf_close separately as qemu_dmabuf_free doesn't
         do it.

     --- 'dmabuf' is now allocated space so it should be freed at the end of
         dbus_scanout_texture

v13: --- Immediately free dmabuf after it is released to prevent possible
         leaking of the ptr
         (Marc-André Lureau <marcandre.lureau@redhat.com>)

     --- Use g_autoptr macro to define *dmabuf for auto clean up instead of
         calling qemu_dmabuf_free
         (Marc-André Lureau <marcandre.lureau@redhat.com>)

v14: --- (vhost-user-gpu) Change qemu_dmabuf_free back to g_clear_pointer
         as it was done because of some misunderstanding (v13).

     --- (vhost-user-gpu) g->dmabuf[m->scanout_id] needs to be set to NULL
         to prevent freed dmabuf to be accessed again in case if(fd==-1)break;
         happens (before new dmabuf is allocated). Otherwise, it would cause
         invalid memory access when the same function is executed. Also NULL
         check should be done before qemu_dmabuf_close (it asserts dmabuf!=NULL.).
         (Marc-André Lureau <marcandre.lureau@redhat.com>)

Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Message-Id: <20240508175403.3399895-6-dongwon.kim@intel.com>

2 files changed, 28 insertions, 27 deletions

diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
index 454e5afcff..e4b398d26c 100644
--- a/hw/display/vhost-user-gpu.c
+++ b/hw/display/vhost-user-gpu.c
@@ -249,6 +249,7 @@ vhost_user_gpu_handle_display(VhostUserGPU *g, VhostUserGpuMsg *msg)
     case VHOST_USER_GPU_DMABUF_SCANOUT: {
         VhostUserGpuDMABUFScanout *m = &msg->payload.dmabuf_scanout;
         int fd = qemu_chr_fe_get_msgfd(&g->vhost_chr);
+        uint64_t modifier = 0;
         QemuDmaBuf *dmabuf;
 
         if (m->scanout_id >= g->parent_obj.conf.max_outputs) {
@@ -261,27 +262,33 @@ vhost_user_gpu_handle_display(VhostUserGPU *g, VhostUserGpuMsg *msg)
 
         g->parent_obj.enable = 1;
         con = g->parent_obj.scanout[m->scanout_id].con;
-        dmabuf = &g->dmabuf[m->scanout_id];
-        qemu_dmabuf_close(dmabuf);
-        dpy_gl_release_dmabuf(con, dmabuf);
+        dmabuf = g->dmabuf[m->scanout_id];
+
+        if (dmabuf) {
+            qemu_dmabuf_close(dmabuf);
+            dpy_gl_release_dmabuf(con, dmabuf);
+            g_clear_pointer(&dmabuf, qemu_dmabuf_free);
+        }
+
         if (fd == -1) {
             dpy_gl_scanout_disable(con);
+            g->dmabuf[m->scanout_id] = NULL;
             break;
         }
-        *dmabuf = (QemuDmaBuf) {
-            .fd = fd,
-            .width = m->fd_width,
-            .height = m->fd_height,
-            .stride = m->fd_stride,
-            .fourcc = m->fd_drm_fourcc,
-            .y0_top = m->fd_flags & VIRTIO_GPU_RESOURCE_FLAG_Y_0_TOP,
-        };
+
         if (msg->request == VHOST_USER_GPU_DMABUF_SCANOUT2) {
             VhostUserGpuDMABUFScanout2 *m2 = &msg->payload.dmabuf_scanout2;
-            dmabuf->modifier = m2->modifier;
+            modifier = m2->modifier;
         }
 
+        dmabuf = qemu_dmabuf_new(m->fd_width, m->fd_height,
+                                 m->fd_stride, 0, 0, 0, 0,
+                                 m->fd_drm_fourcc, modifier,
+                                 fd, false, m->fd_flags &
+                                 VIRTIO_GPU_RESOURCE_FLAG_Y_0_TOP);
+
         dpy_gl_scanout_dmabuf(con, dmabuf);
+        g->dmabuf[m->scanout_id] = dmabuf;
         break;
     }
     case VHOST_USER_GPU_DMABUF_UPDATE: {
diff --git a/hw/display/virtio-gpu-udmabuf.c b/hw/display/virtio-gpu-udmabuf.c
index c90eba281e..c02ec6d37d 100644
--- a/hw/display/virtio-gpu-udmabuf.c
+++ b/hw/display/virtio-gpu-udmabuf.c
@@ -162,7 +162,8 @@ static void virtio_gpu_free_dmabuf(VirtIOGPU *g, VGPUDMABuf *dmabuf)
     struct virtio_gpu_scanout *scanout;
 
     scanout = &g->parent_obj.scanout[dmabuf->scanout_id];
-    dpy_gl_release_dmabuf(scanout->con, &dmabuf->buf);
+    dpy_gl_release_dmabuf(scanout->con, dmabuf->buf);
+    g_clear_pointer(&dmabuf->buf, qemu_dmabuf_free);
     QTAILQ_REMOVE(&g->dmabuf.bufs, dmabuf, next);
     g_free(dmabuf);
 }
@@ -181,17 +182,10 @@ static VGPUDMABuf
     }
 
     dmabuf = g_new0(VGPUDMABuf, 1);
-    dmabuf->buf.width = r->width;
-    dmabuf->buf.height = r->height;
-    dmabuf->buf.stride = fb->stride;
-    dmabuf->buf.x = r->x;
-    dmabuf->buf.y = r->y;
-    dmabuf->buf.backing_width = fb->width;
-    dmabuf->buf.backing_height = fb->height;
-    dmabuf->buf.fourcc = qemu_pixman_to_drm_format(fb->format);
-    dmabuf->buf.fd = res->dmabuf_fd;
-    dmabuf->buf.allow_fences = true;
-    dmabuf->buf.draw_submitted = false;
+    dmabuf->buf = qemu_dmabuf_new(r->width, r->height, fb->stride,
+                                  r->x, r->y, fb->width, fb->height,
+                                  qemu_pixman_to_drm_format(fb->format),
+                                  0, res->dmabuf_fd, true, false);
     dmabuf->scanout_id = scanout_id;
     QTAILQ_INSERT_HEAD(&g->dmabuf.bufs, dmabuf, next);
 
@@ -217,11 +211,11 @@ int virtio_gpu_update_dmabuf(VirtIOGPU *g,
         old_primary = g->dmabuf.primary[scanout_id];
     }
 
-    width = qemu_dmabuf_get_width(&new_primary->buf);
-    height = qemu_dmabuf_get_height(&new_primary->buf);
+    width = qemu_dmabuf_get_width(new_primary->buf);
+    height = qemu_dmabuf_get_height(new_primary->buf);
     g->dmabuf.primary[scanout_id] = new_primary;
     qemu_console_resize(scanout->con, width, height);
-    dpy_gl_scanout_dmabuf(scanout->con, &new_primary->buf);
+    dpy_gl_scanout_dmabuf(scanout->con, new_primary->buf);
 
     if (old_primary) {
         virtio_gpu_free_dmabuf(g, old_primary);