[RFC PATCH] contrib/plugins: avoid hanging program

["Alex Bennée" <alex.bennee@linaro.org>]

Although we asks for instructions per second we work in quanta and
that cannot be 0. Fail to load the plugin instead and report the
minimum IPS we can handle.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Elisha Hollander <just4now666666@gmail.com>
---
 contrib/plugins/ips.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/contrib/plugins/ips.c b/contrib/plugins/ips.c
index 29fa556d0f..6f078689dc 100644
--- a/contrib/plugins/ips.c
+++ b/contrib/plugins/ips.c
@@ -152,6 +152,11 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
     vcpus = qemu_plugin_scoreboard_new(sizeof(vCPUTime));
     max_insn_per_quantum = max_insn_per_second / NUM_TIME_UPDATE_PER_SEC;
 
+    if (max_insn_per_quantum == 0) {
+        fprintf(stderr, "minimum of %d instructions per second needed\n", NUM_TIME_UPDATE_PER_SEC);
+        return -1;
+    }
+
     time_handle = qemu_plugin_request_time_control();
     g_assert(time_handle);
 
-- 
2.39.2