On 9/13/24 10:38, Alex Bennée wrote:
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.ben...@linaro.org> Reported-by: Elisha Hollander <just4now666...@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);
The ips plugin uses tb based trap, so it should not be expected that an ips of 1 will do what is expected (it will execute the whole tb at minimum).
Either we could extend this plugin with a precise mode (instruction based), or simply emit an error when ips is too low, like < 100.
I'm more in favor of the latter solution. Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org>
