Re: [PATCH v15 10/14] virtio-gpu: Support blob scanout using dmabuf fd

[Akihiko Odaki]

On 2024/06/23 6:55, Dmitry Osipenko wrote:

From: Robert Beckett <bob.beck...@collabora.com>

Support displaying blob resources by handling SET_SCANOUT_BLOB
command.

Signed-by: Antonio Caggiano <antonio.caggi...@collabora.com>
Signed-off-by: Robert Beckett <bob.beck...@collabora.com>
Signed-off-by: Huang Rui <ray.hu...@amd.com>
Reviewed-by: Antonio Caggiano <quic_acagg...@quicinc.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipe...@collabora.com>
---
  hw/display/virtio-gpu-virgl.c  | 109 +++++++++++++++++++++++++++++++++
  hw/display/virtio-gpu.c        |  12 ++--
  include/hw/virtio/virtio-gpu.h |   7 +++
  3 files changed, 122 insertions(+), 6 deletions(-)

diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
index 3ffea478e723..60befab7efc2 100644
--- a/hw/display/virtio-gpu-virgl.c
+++ b/hw/display/virtio-gpu-virgl.c
@@ -17,6 +17,8 @@
  #include "trace.h"
  #include "hw/virtio/virtio.h"
  #include "hw/virtio/virtio-gpu.h"
+#include "hw/virtio/virtio-gpu-bswap.h"
+#include "hw/virtio/virtio-gpu-pixman.h"

#include "ui/egl-helpers.h" @@ -78,6 +80,7 @@ static void virgl_cmd_create_resource_2d(VirtIOGPU *g,

      res->base.height = c2d.height;
      res->base.format = c2d.format;
      res->base.resource_id = c2d.resource_id;
+    res->base.dmabuf_fd = -1;
      QTAILQ_INSERT_HEAD(&g->reslist, &res->base, next);

args.handle = c2d.resource_id;

@@ -125,6 +128,7 @@ static void virgl_cmd_create_resource_3d(VirtIOGPU *g,
      res->base.height = c3d.height;
      res->base.format = c3d.format;
      res->base.resource_id = c3d.resource_id;
+    res->base.dmabuf_fd = -1;
      QTAILQ_INSERT_HEAD(&g->reslist, &res->base, next);

args.handle = c3d.resource_id;

@@ -509,6 +513,106 @@ static void virgl_cmd_get_capset(VirtIOGPU *g,
      g_free(resp);
  }

+#if VIRGL_VERSION_MAJOR >= 1

+static void virgl_cmd_set_scanout_blob(VirtIOGPU *g,
+                                       struct virtio_gpu_ctrl_command *cmd)
+{
+    struct virtio_gpu_framebuffer fb = { 0 };
+    struct virgl_renderer_resource_info info;
+    struct virtio_gpu_virgl_resource *res;
+    struct virtio_gpu_set_scanout_blob ss;
+    uint64_t fbend;
+
+    VIRTIO_GPU_FILL_CMD(ss);
+    virtio_gpu_scanout_blob_bswap(&ss);
+    trace_virtio_gpu_cmd_set_scanout_blob(ss.scanout_id, ss.resource_id,
+                                          ss.r.width, ss.r.height, ss.r.x,
+                                          ss.r.y);
+
+    if (ss.scanout_id >= g->parent_obj.conf.max_outputs) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout id specified %d",
+                      __func__, ss.scanout_id);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_SCANOUT_ID;
+        return;
+    }
+
+    if (ss.resource_id == 0) {
+        virtio_gpu_disable_scanout(g, ss.scanout_id);
+        return;
+    }
+
+    if (ss.width < 16 ||
+        ss.height < 16 ||
+        ss.r.x + ss.r.width > ss.width ||
+        ss.r.y + ss.r.height > ss.height) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout %d bounds for"
+                      " resource %d, rect (%d,%d)+%d,%d, fb %d %d\n",
+                      __func__, ss.scanout_id, ss.resource_id,
+                      ss.r.x, ss.r.y, ss.r.width, ss.r.height,
+                      ss.width, ss.height);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+        return;
+    }
+
+    res = virtio_gpu_virgl_find_resource(g, ss.resource_id);
+    if (!res) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource does not exist %d\n",
+                      __func__, ss.resource_id);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+    if (virgl_renderer_resource_get_info(ss.resource_id, &info)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource does not have info %d\n",
+                      __func__, ss.resource_id);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+    if (res->base.dmabuf_fd < 0) {
+        res->base.dmabuf_fd = info.fd;

Just in case you missed my previous email:
> res->base.dmabuf_fd is conditionally assigned but
> virgl_renderer_resource_get_info() is called unconditionally, which is
> inconsistent.

> The relevant code is better to be moved into
> virgl_cmd_resource_create_blob() for consistenty with
> virtio_gpu_resource_create_blob().