bql: add a "mock" BQL for Rust unit tests

Right now, the stub BQL in stubs/iothread-lock.c always reports itself as
unlocked.  However, Rust would like to run its tests in an environment where
the BQL *is* locked.  Provide an extremely dirty function that flips the
return value of bql_is_locked() to true.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index 646306c272..3935a57339 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -248,6 +248,14 @@ GSource *iohandler_get_g_source(void);
 AioContext *iohandler_get_aio_context(void);
 
 /**
+ * rust_bql_mock_lock:
+ *
+ * Called from Rust doctests to make bql_lock() return true.
+ * Do not touch.
+ */
+void rust_bql_mock_lock(void);
+
+/**
  * bql_locked: Return lock status of the Big QEMU Lock (BQL)
  *
  * The Big QEMU Lock (BQL) is the coarsest lock in QEMU, and as such it