[Qemu-devel] [PATCH v2 4/6] virtio-gpu: maintain command queue

[Gerd Hoffmann <kraxel@redhat.com>]

We'll go take out the commands we receive out of the virt queue and put
them into a linked list, to decouple virtio queue handling from actual
command processing.

Also move cmd processing to new virtio_gpu_handle_ctrl func, so we can
easily kick it from different places.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/display/virtio-gpu.c        | 63 +++++++++++++++++++++++++++---------------
 include/hw/virtio/virtio-gpu.h |  1 +
 2 files changed, 42 insertions(+), 22 deletions(-)

diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 7e79a9c..d4ee34d 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -754,33 +754,21 @@ static void virtio_gpu_handle_cursor_cb(VirtIODevice *vdev, VirtQueue *vq)
     qemu_bh_schedule(g->cursor_bh);
 }
 
-static void virtio_gpu_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+static void virtio_gpu_process_cmdq(VirtIOGPU *g)
 {
-    VirtIOGPU *g = VIRTIO_GPU(vdev);
     struct virtio_gpu_ctrl_command *cmd;
 
-    if (!virtio_queue_ready(vq)) {
-        return;
-    }
-
-#ifdef CONFIG_VIRGL
-    if (!g->renderer_inited && g->use_virgl_renderer) {
-        virtio_gpu_virgl_init(g);
-        g->renderer_inited = true;
-    }
-#endif
-
-    cmd = g_new(struct virtio_gpu_ctrl_command, 1);
-    while (virtqueue_pop(vq, &cmd->elem)) {
-        cmd->vq = vq;
-        cmd->error = 0;
-        cmd->finished = false;
-        if (virtio_gpu_stats_enabled(g->conf)) {
-            g->stats.requests++;
-        }
+    while (!QTAILQ_EMPTY(&g->cmdq)) {
+        cmd = QTAILQ_FIRST(&g->cmdq);
 
+        /* process command */
         VIRGL(g, virtio_gpu_virgl_process_cmd, virtio_gpu_simple_process_cmd,
               g, cmd);
+        QTAILQ_REMOVE(&g->cmdq, cmd, next);
+        if (virtio_gpu_stats_enabled(g->conf)) {
+            g->stats.requests++;
+        }
+
         if (!cmd->finished) {
             QTAILQ_INSERT_TAIL(&g->fenceq, cmd, next);
             g->inflight++;
@@ -790,11 +778,41 @@ static void virtio_gpu_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
                 }
                 fprintf(stderr, "inflight: %3d (+)\r", g->inflight);
             }
-            cmd = g_new(struct virtio_gpu_ctrl_command, 1);
+        } else {
+            g_free(cmd);
         }
     }
+}
+
+static void virtio_gpu_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIOGPU *g = VIRTIO_GPU(vdev);
+    struct virtio_gpu_ctrl_command *cmd;
+
+    if (!virtio_queue_ready(vq)) {
+        return;
+    }
+
+#ifdef CONFIG_VIRGL
+    if (!g->renderer_inited && g->use_virgl_renderer) {
+        virtio_gpu_virgl_init(g);
+        g->renderer_inited = true;
+    }
+#endif
+
+    cmd = g_new(struct virtio_gpu_ctrl_command, 1);
+    while (virtqueue_pop(vq, &cmd->elem)) {
+        cmd->vq = vq;
+        cmd->error = 0;
+        cmd->finished = false;
+        cmd->waiting = false;
+        QTAILQ_INSERT_TAIL(&g->cmdq, cmd, next);
+        cmd = g_new(struct virtio_gpu_ctrl_command, 1);
+    }
     g_free(cmd);
 
+    virtio_gpu_process_cmdq(g);
+
 #ifdef CONFIG_VIRGL
     if (g->use_virgl_renderer) {
         virtio_gpu_virgl_fence_poll(g);
@@ -920,6 +938,7 @@ static void virtio_gpu_device_realize(DeviceState *qdev, Error **errp)
     g->ctrl_bh = qemu_bh_new(virtio_gpu_ctrl_bh, g);
     g->cursor_bh = qemu_bh_new(virtio_gpu_cursor_bh, g);
     QTAILQ_INIT(&g->reslist);
+    QTAILQ_INIT(&g->cmdq);
     QTAILQ_INIT(&g->fenceq);
 
     g->enabled_output_bitmask = 1;
diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
index 9b279d7..f7e7a52 100644
--- a/include/hw/virtio/virtio-gpu.h
+++ b/include/hw/virtio/virtio-gpu.h
@@ -94,6 +94,7 @@ typedef struct VirtIOGPU {
     DeviceState *qdev;
 
     QTAILQ_HEAD(, virtio_gpu_simple_resource) reslist;
+    QTAILQ_HEAD(, virtio_gpu_ctrl_command) cmdq;
     QTAILQ_HEAD(, virtio_gpu_ctrl_command) fenceq;
 
     struct virtio_gpu_scanout scanout[VIRTIO_GPU_MAX_SCANOUT];
-- 
1.8.3.1