virtio-gpu: avoid re-entering cmdq processing

The next patch will notify the GL context got flush, which will resume
the queue processing. However, if this happens within the caller
context, it will end up with a stack overflow flush/update loop.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210204105232.834642-18-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 0e833a462bae83a1b6c86305c182cef4ff6dbf8e..7eb4265a6da7f05808d7c1955d56ddf1188a2de3 100644 (file)
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -814,6 +814,10 @@ void virtio_gpu_process_cmdq(VirtIOGPU *g)
 {
     struct virtio_gpu_ctrl_command *cmd;
 
+    if (g->processing_cmdq) {
+        return;
+    }
+    g->processing_cmdq = true;
     while (!QTAILQ_EMPTY(&g->cmdq)) {
         cmd = QTAILQ_FIRST(&g->cmdq);
 
@@ -843,6 +847,7 @@ void virtio_gpu_process_cmdq(VirtIOGPU *g)
             g_free(cmd);
         }
     }
+    g->processing_cmdq = false;
 }
 
 static void virtio_gpu_gl_unblock(VirtIOGPUBase *b)

diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
index 4f3dbf79f9bca60bb0dc55e98190896b26405fe7..0043268e9021f470ac9485992f1de3bc2593e6a5 100644 (file)
--- a/include/hw/virtio/virtio-gpu.h
+++ b/include/hw/virtio/virtio-gpu.h
@@ -148,6 +148,7 @@ struct VirtIOGPU {
 
     uint64_t hostmem;
 
+    bool processing_cmdq;
     bool renderer_inited;
     bool renderer_reset;
     QEMUTimer *fence_poll;