Re: [PATCH v4 3/3] ui/console: Introduce dpy_gl_create_dmabuf() helper

[Marc-André Lureau]

Hi

On Fri, Mar 22, 2024 at 3:45 AM <dongwon.kim@intel.com> wrote:
>
> From: Dongwon Kim <dongwon.kim@intel.com>
>
> dpy_gl_create_dmabuf() allocates QemuDmaBuf and initialize fields.
> hw/display modules, hw/vfio and ui/dbus-listener now use this method
> to create QemuDmaBuf instead of declaring and initializing it on their
> own.
>
> Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
> Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
> Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
> Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
> ---
>  include/hw/vfio/vfio-common.h   |  2 +-
>  include/hw/virtio/virtio-gpu.h  |  4 ++--
>  include/ui/console.h            |  6 ++++++
>  hw/display/vhost-user-gpu.c     | 33 ++++++++++++++++++---------------
>  hw/display/virtio-gpu-udmabuf.c | 23 ++++++++---------------
>  hw/vfio/display.c               | 26 +++++++++++---------------
>  ui/console.c                    | 28 ++++++++++++++++++++++++++++
>  ui/dbus-listener.c              | 28 ++++++++++++----------------
>  8 files changed, 86 insertions(+), 64 deletions(-)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index b9da6c08ef..d66e27db02 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -148,7 +148,7 @@ typedef struct VFIOGroup {
>  } VFIOGroup;
>
>  typedef struct VFIODMABuf {
> -    QemuDmaBuf buf;
> +    QemuDmaBuf *buf;
>      uint32_t pos_x, pos_y, pos_updates;
>      uint32_t hot_x, hot_y, hot_updates;
>      int dmabuf_id;
> diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
> index ed44cdad6b..56d6e821bf 100644
> --- a/include/hw/virtio/virtio-gpu.h
> +++ b/include/hw/virtio/virtio-gpu.h
> @@ -169,7 +169,7 @@ struct VirtIOGPUBaseClass {
>      DEFINE_PROP_UINT32("yres", _state, _conf.yres, 800)
>
>  typedef struct VGPUDMABuf {
> -    QemuDmaBuf buf;
> +    QemuDmaBuf *buf;
>      uint32_t scanout_id;
>      QTAILQ_ENTRY(VGPUDMABuf) next;
>  } VGPUDMABuf;
> @@ -238,7 +238,7 @@ struct VhostUserGPU {
>      VhostUserBackend *vhost;
>      int vhost_gpu_fd; /* closed by the chardev */
>      CharBackend vhost_chr;
> -    QemuDmaBuf dmabuf[VIRTIO_GPU_MAX_SCANOUTS];
> +    QemuDmaBuf *dmabuf[VIRTIO_GPU_MAX_SCANOUTS];
>      bool backend_blocked;
>  };
>
> diff --git a/include/ui/console.h b/include/ui/console.h
> index d5334a806c..01e998264b 100644
> --- a/include/ui/console.h
> +++ b/include/ui/console.h
> @@ -358,6 +358,12 @@ void dpy_gl_cursor_dmabuf(QemuConsole *con, QemuDmaBuf 
> *dmabuf,
>                            bool have_hot, uint32_t hot_x, uint32_t hot_y);
>  void dpy_gl_cursor_position(QemuConsole *con,
>                              uint32_t pos_x, uint32_t pos_y);
> +QemuDmaBuf *dpy_gl_create_dmabuf(uint32_t width, uint32_t height,
> +                                 uint32_t stride, uint32_t x,
> +                                 uint32_t y, uint32_t backing_width,
> +                                 uint32_t backing_height, uint32_t fourcc,
> +                                 uint64_t modifier, uint32_t dmabuf_fd,
> +                                 bool allow_fences, bool y0_top);
>  uint32_t dpy_gl_dmabuf_get_width(QemuDmaBuf *dmabuf);
>  uint32_t dpy_gl_dmabuf_get_height(QemuDmaBuf *dmabuf);
>  int32_t dpy_gl_dmabuf_get_fd(QemuDmaBuf *dmabuf);
> diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
> index 709c8a02a1..0e49a934ed 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) {
> @@ -261,30 +262,32 @@ 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];
> -        if (dmabuf->fd >= 0) {
> -            close(dmabuf->fd);
> -            dmabuf->fd = -1;
> +        dmabuf = g->dmabuf[m->scanout_id];
> +        if (dmabuf) {
> +            int dmabuf_fd = dpy_gl_dmabuf_get_fd(dmabuf);
> +            if (dmabuf_fd >= 0) {
> +                close(dmabuf_fd);
> +            }
> +            dpy_gl_release_dmabuf(con, dmabuf);
>          }
> -        dpy_gl_release_dmabuf(con, dmabuf);
> +
>          if (fd == -1) {
>              dpy_gl_scanout_disable(con);
>              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;
>          }
>
> -        dpy_gl_scanout_dmabuf(con, dmabuf);
> +        dmabuf = dpy_gl_create_dmabuf(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, g->dmabuf[m->scanout_id]);
> +        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 a4ebf828ec..2bc8697d86 100644
> --- a/hw/display/virtio-gpu-udmabuf.c
> +++ b/hw/display/virtio-gpu-udmabuf.c
> @@ -162,7 +162,7 @@ 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);
>      QTAILQ_REMOVE(&g->dmabuf.bufs, dmabuf, next);
>      g_free(dmabuf);
>  }
> @@ -181,17 +181,10 @@ 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 = dpy_gl_create_dmabuf(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, false, 0);
>      dmabuf->scanout_id = scanout_id;
>      QTAILQ_INSERT_HEAD(&g->dmabuf.bufs, dmabuf, next);
>
> @@ -217,11 +210,11 @@ int virtio_gpu_update_dmabuf(VirtIOGPU *g,
>          old_primary = g->dmabuf.primary[scanout_id];
>      }
>
> -    width = dpy_gl_dmabuf_get_width(&new_primary->buf);
> -    height = dpy_gl_dmabuf_get_height(&new_primary->buf);
> +    width = dpy_gl_dmabuf_get_width(new_primary->buf);
> +    height = dpy_gl_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);
> diff --git a/hw/vfio/display.c b/hw/vfio/display.c
> index 676b2fc5f3..62f5db2d54 100644
> --- a/hw/vfio/display.c
> +++ b/hw/vfio/display.c
> @@ -240,15 +240,11 @@ static VFIODMABuf 
> *vfio_display_get_dmabuf(VFIOPCIDevice *vdev,
>      }
>
>      dmabuf = g_new0(VFIODMABuf, 1);
> -    dmabuf->dmabuf_id  = plane.dmabuf_id;
> -    dmabuf->buf.width  = plane.width;
> -    dmabuf->buf.height = plane.height;
> -    dmabuf->buf.backing_width = plane.width;
> -    dmabuf->buf.backing_height = plane.height;
> -    dmabuf->buf.stride = plane.stride;
> -    dmabuf->buf.fourcc = plane.drm_format;
> -    dmabuf->buf.modifier = plane.drm_format_mod;
> -    dmabuf->buf.fd     = fd;
> +    dmabuf->dmabuf_id = plane.dmabuf_id;
> +    dmabuf->buf = dpy_gl_create_dmabuf(plane.width, plane.height, 
> plane.stride,
> +                                       0, 0, plane.width, plane.height,
> +                                       plane.drm_format, 
> plane.drm_format_mod,
> +                                       fd, false, 0);
>      if (plane_type == DRM_PLANE_TYPE_CURSOR) {
>          vfio_display_update_cursor(dmabuf, &plane);
>      }
> @@ -262,12 +258,12 @@ static void vfio_display_free_one_dmabuf(VFIODisplay 
> *dpy, VFIODMABuf *dmabuf)
>      int fd;
>
>      QTAILQ_REMOVE(&dpy->dmabuf.bufs, dmabuf, next);
> -    fd = dpy_gl_dmabuf_get_fd(&dmabuf->buf);
> +    fd = dpy_gl_dmabuf_get_fd(dmabuf->buf);
>      if (fd > -1) {
>          close(fd);
>      }
>
> -    dpy_gl_release_dmabuf(dpy->con, &dmabuf->buf);
> +    dpy_gl_release_dmabuf(dpy->con, dmabuf->buf);
>      g_free(dmabuf);
>  }
>
> @@ -303,13 +299,13 @@ static void vfio_display_dmabuf_update(void *opaque)
>          return;
>      }
>
> -    width = dpy_gl_dmabuf_get_width(&primary->buf);
> -    height = dpy_gl_dmabuf_get_height(&primary->buf);
> +    width = dpy_gl_dmabuf_get_width(primary->buf);
> +    height = dpy_gl_dmabuf_get_height(primary->buf);
>
>      if (dpy->dmabuf.primary != primary) {
>          dpy->dmabuf.primary = primary;
>          qemu_console_resize(dpy->con, width, height);
> -        dpy_gl_scanout_dmabuf(dpy->con, &primary->buf);
> +        dpy_gl_scanout_dmabuf(dpy->con, primary->buf);
>          free_bufs = true;
>      }
>
> @@ -323,7 +319,7 @@ static void vfio_display_dmabuf_update(void *opaque)
>      if (cursor && (new_cursor || cursor->hot_updates)) {
>          bool have_hot = (cursor->hot_x != 0xffffffff &&
>                           cursor->hot_y != 0xffffffff);
> -        dpy_gl_cursor_dmabuf(dpy->con, &cursor->buf, have_hot,
> +        dpy_gl_cursor_dmabuf(dpy->con, cursor->buf, have_hot,
>                               cursor->hot_x, cursor->hot_y);
>          cursor->hot_updates = 0;
>      } else if (!cursor && new_cursor) {
> diff --git a/ui/console.c b/ui/console.c
> index 69560aac7e..f3920e7713 100644
> --- a/ui/console.c
> +++ b/ui/console.c
> @@ -1132,6 +1132,33 @@ void dpy_gl_cursor_position(QemuConsole *con,
>      }
>  }
>
> +QemuDmaBuf *dpy_gl_create_dmabuf(uint32_t width, uint32_t height,
> +                                 uint32_t stride, uint32_t x,
> +                                 uint32_t y, uint32_t backing_width,
> +                                 uint32_t backing_height, uint32_t fourcc,
> +                                 uint64_t modifier, uint32_t dmabuf_fd,
> +                                 bool allow_fences, bool y0_top) {

We usually follow glib conventions, name the function according to the
type allocated, and add a "_new" suffix: qemu_dma_buf_new()

> +    QemuDmaBuf *dmabuf;
> +
> +    dmabuf = g_new0(QemuDmaBuf, 1);
> +
> +    dmabuf->width = width;
> +    dmabuf->height = height;
> +    dmabuf->stride = stride;
> +    dmabuf->x = x;
> +    dmabuf->y = y;
> +    dmabuf->backing_width = backing_width;
> +    dmabuf->backing_height = backing_height;
> +    dmabuf->fourcc = fourcc;
> +    dmabuf->modifier = modifier;
> +    dmabuf->fd = dmabuf_fd;
> +    dmabuf->allow_fences = allow_fences;
> +    dmabuf->y0_top = y0_top;
> +    dmabuf->fence_fd = -1;
> +
> +    return dmabuf;
> +}
> +
>  uint32_t dpy_gl_dmabuf_get_width(QemuDmaBuf *dmabuf)
>  {
>      if (dmabuf) {
> @@ -1164,6 +1191,7 @@ void dpy_gl_release_dmabuf(QemuConsole *con,
>              dcl->ops->dpy_gl_release_dmabuf(dcl, dmabuf);
>          }
>      }
> +    g_free(dmabuf);

This is not a good place to free dmabuf, since it's a place to notify
console listeners. I suggest introducing another function,
qemu_dma_buf_free(). And to use it through g_clear_pointer(&buf,
qemu_dma_buf_free), to avoid dangling pointers later.

>  }
>
>  void dpy_gl_update(QemuConsole *con,
> diff --git a/ui/dbus-listener.c b/ui/dbus-listener.c
> index 4a0a5d78f9..a2145704cc 100644
> --- a/ui/dbus-listener.c
> +++ b/ui/dbus-listener.c
> @@ -438,28 +438,24 @@ static void dbus_scanout_texture(DisplayChangeListener 
> *dcl,
>      trace_dbus_scanout_texture(tex_id, backing_y_0_top,
>                                 backing_width, backing_height, x, y, w, h);
>  #ifdef CONFIG_GBM
> -    QemuDmaBuf dmabuf = {
> -        .width = w,
> -        .height = h,
> -        .y0_top = backing_y_0_top,
> -        .x = x,
> -        .y = y,
> -        .backing_width = backing_width,
> -        .backing_height = backing_height,
> -    };
> +    int32_t fd;
> +    uint32_t stride, fourcc;
> +    uint64_t modifier;
> +    QemuDmaBuf *dmabuf;
>
>      assert(tex_id);
> -    dmabuf.fd = egl_get_fd_for_texture(
> -        tex_id, (EGLint *)&dmabuf.stride,
> -        (EGLint *)&dmabuf.fourcc,
> -        &dmabuf.modifier);
> -    if (dmabuf.fd < 0) {
> +    fd = egl_get_fd_for_texture(tex_id, (EGLint *)&stride, (EGLint *)&fourcc,
> +                                &modifier);
> +    if (fd < 0) {
>          error_report("%s: failed to get fd for texture", __func__);
>          return;
>      }
> +    dmabuf = dpy_gl_create_dmabuf(w, h, stride, x, y, backing_width,
> +                                  backing_height, fourcc, modifier, fd,
> +                                  false, backing_y_0_top);
>
> -    dbus_scanout_dmabuf(dcl, &dmabuf);
> -    close(dmabuf.fd);
> +    dbus_scanout_dmabuf(dcl, dmabuf);
> +    close(fd);
>  #endif
>
>  #ifdef WIN32
> --
> 2.34.1
>
>


-- 
Marc-André Lureau