main-loop: Suppress "I/O thread spun" warnings for qtest

When running under qtest we don't actually have any vcpu threads
to be starved, so the warning about the I/O thread spinning isn't
relevant, and the way qtest manipulates the simulated clock means
the warning is produced a lot as a false positive. Suppress it if
qtest_enabled(), so 'make check' output is less noisy.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

main-loop.c

@@ -25,6 +25,7 @@
 #include "qemu-common.h"
 #include "qemu/timer.h"
 #include "qemu/sockets.h"	// struct in_addr needed for libslirp.h
+#include "sysemu/qtest.h"
 #include "slirp/libslirp.h"
 #include "qemu/main-loop.h"
 #include "block/aio.h"
@@ -208,7 +209,7 @@ static int os_host_main_loop_wait(int64_t timeout)
     if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
         static bool notified;
 
-        if (!notified) {
+        if (!notified && !qtest_enabled()) {
             fprintf(stderr,
                     "main-loop: WARNING: I/O thread spun for %d iterations\n",
                     MAX_MAIN_LOOP_SPIN);

stubs/Makefile.objs

@@ -18,6 +18,7 @@ stub-obj-y += mon-print-filename.o
 stub-obj-y += mon-protocol-event.o
 stub-obj-y += mon-set-error.o
 stub-obj-y += pci-drive-hot-add.o
+stub-obj-y += qtest.o
 stub-obj-y += reset.o
 stub-obj-y += set-fd-handler.o
 stub-obj-y += slirp.o

stubs/qtest.c

@@ -0,0 +1,14 @@
+/*
+ * qtest stubs
+ *
+ * Copyright (c) 2014 Linaro Limited
+ * Written by Peter Maydell
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu-common.h"
+
+/* Needed for qtest_allowed() */
+bool qtest_allowed;