vrend: make sure queries are fenced

Check queries from within vrend_renderer_check_fences, after
glClientWaitSync but before write_fence.  This makes sure query
results are available after the fence is waited for.

In other words, given this sequence of commands

  BEGIN_QUERY > DRAW_VBO > END_QUERY > GET_QUERY_RESULT > FENCE

Waiting on the fence makes sure the query result becomes available
to the guest.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/virglrenderer.c

@@ -299,7 +299,6 @@ void *virgl_renderer_get_cursor_data(uint32_t resource_id, uint32_t *width, uint
 
 void virgl_renderer_poll(void)
 {
-   vrend_renderer_check_queries();
    vrend_renderer_check_fences();
 }
 

src/vrend_renderer.c

@@ -7995,6 +7995,8 @@ static void flush_eventfd(int fd)
     } while ((len == -1 && errno == EINTR) || len == sizeof(value));
 }
 
+static void vrend_renderer_check_queries(void);
+
 void vrend_renderer_check_fences(void)
 {
    struct vrend_fence *fence, *stor;
@@ -8031,6 +8033,9 @@ void vrend_renderer_check_fences(void)
 
    if (latest_id == 0)
       return;
+
+   vrend_renderer_check_queries();
+
    vrend_clicbs->write_fence(latest_id);
 }
 
@@ -8071,13 +8076,10 @@ static bool vrend_check_query(struct vrend_query *query)
    return true;
 }
 
-void vrend_renderer_check_queries(void)
+static void vrend_renderer_check_queries(void)
 {
    struct vrend_query *query, *stor;
 
-   if (!vrend_state.inited)
-      return;
-
    LIST_FOR_EACH_ENTRY_SAFE(query, stor, &vrend_state.waiting_query_list, waiting_queries) {
       vrend_hw_switch_context(vrend_lookup_renderer_ctx(query->ctx_id), true);
       if (vrend_check_query(query))

src/vrend_renderer.h

@@ -316,7 +316,6 @@ struct vrend_context *vrend_lookup_renderer_ctx(uint32_t ctx_id);
 int vrend_renderer_create_fence(int client_fence_id, uint32_t ctx_id);
 
 void vrend_renderer_check_fences(void);
-void vrend_renderer_check_queries(void);
 
 bool vrend_hw_switch_context(struct vrend_context *ctx, bool now);
 uint32_t vrend_renderer_object_insert(struct vrend_context *ctx, void *data,