vhost-user-gpu: use an extandable state enum for commands

Introduce a pending state for commands which aren't finished yet, but
are being handled. See following patch.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210204105232.834642-4-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

contrib/vhost-user-gpu/vhost-user-gpu.c

@@ -246,7 +246,7 @@ vg_ctrl_response(VuGpu *g,
     }
     vu_queue_push(&g->dev.parent, cmd->vq, &cmd->elem, s);
     vu_queue_notify(&g->dev.parent, cmd->vq);
-    cmd->finished = true;
+    cmd->state = VG_CMD_STATE_FINISHED;
 }
 
 void
@@ -800,7 +800,7 @@ vg_process_cmd(VuGpu *vg, struct virtio_gpu_ctrl_command *cmd)
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         break;
     }
-    if (!cmd->finished) {
+    if (cmd->state == VG_CMD_STATE_NEW) {
         vg_ctrl_response_nodata(vg, cmd, cmd->error ? cmd->error :
                                 VIRTIO_GPU_RESP_OK_NODATA);
     }
@@ -825,7 +825,7 @@ vg_handle_ctrl(VuDev *dev, int qidx)
         }
         cmd->vq = vq;
         cmd->error = 0;
-        cmd->finished = false;
+        cmd->state = VG_CMD_STATE_NEW;
 
         len = iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num,
                          0, &cmd->cmd_hdr, sizeof(cmd->cmd_hdr));
@@ -844,7 +844,7 @@ vg_handle_ctrl(VuDev *dev, int qidx)
             vg_process_cmd(vg, cmd);
         }
 
-        if (!cmd->finished) {
+        if (cmd->state != VG_CMD_STATE_FINISHED) {
             QTAILQ_INSERT_TAIL(&vg->fenceq, cmd, next);
             vg->inflight++;
         } else {

contrib/vhost-user-gpu/virgl.c

@@ -482,7 +482,7 @@ void vg_virgl_process_cmd(VuGpu *g, struct virtio_gpu_ctrl_command *cmd)
         break;
     }
 
-    if (cmd->finished) {
+    if (cmd->state != VG_CMD_STATE_NEW) {
         return;
     }
 

contrib/vhost-user-gpu/vugpu.h

@@ -129,12 +129,18 @@ typedef struct VuGpu {
     QTAILQ_HEAD(, virtio_gpu_ctrl_command) fenceq;
 } VuGpu;
 
+enum {
+    VG_CMD_STATE_NEW,
+    VG_CMD_STATE_PENDING,
+    VG_CMD_STATE_FINISHED,
+};
+
 struct virtio_gpu_ctrl_command {
     VuVirtqElement elem;
     VuVirtq *vq;
     struct virtio_gpu_ctrl_hdr cmd_hdr;
     uint32_t error;
-    bool finished;
+    int state;
     QTAILQ_ENTRY(virtio_gpu_ctrl_command) next;
 };