Mahmoud Mandour writes:
> Added a table-like output which contains the total number of calls
> for each used syscall along with the number of errors that occurred.
>
> Per-call tracing is still available through supplying the argument
> ``print`` to the plugin.
>
> Signed-off-by: Mahmoud Mandour
Queued to plugins/next, thanks.
> ---
> v3 -> v4: Added a missing ``static`` that was causing a compilation
> error. Otherwise, everything else is left in place.
> tests/plugin/syscall.c | 98 +++---
> 1 file changed, 93 insertions(+), 5 deletions(-)
>
> diff --git a/tests/plugin/syscall.c b/tests/plugin/syscall.c
> index 53ee2ab6c4..6dd71092e1 100644
> --- a/tests/plugin/syscall.c
> +++ b/tests/plugin/syscall.c
> @@ -16,32 +16,120 @@
>
> QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
>
> +typedef struct {
> +int64_t num;
> +int64_t calls;
> +int64_t errors;
> +} SyscallStats;
> +
> +static GMutex lock;
> +static GHashTable *statistics;
> +
> +static SyscallStats *get_or_create_entry(int64_t num)
> +{
> +SyscallStats *entry =
> +(SyscallStats *) g_hash_table_lookup(statistics,
> GINT_TO_POINTER(num));
> +
> +if (!entry) {
> +entry = g_new0(SyscallStats, 1);
> +entry->num = num;
> +g_hash_table_insert(statistics, GINT_TO_POINTER(num), (gpointer)
> entry);
> +}
> +
> +return entry;
> +}
> +
> static void vcpu_syscall(qemu_plugin_id_t id, unsigned int vcpu_index,
> int64_t num, uint64_t a1, uint64_t a2,
> uint64_t a3, uint64_t a4, uint64_t a5,
> uint64_t a6, uint64_t a7, uint64_t a8)
> {
> -g_autofree gchar *out = g_strdup_printf("syscall #%" PRIi64 "\n", num);
> -qemu_plugin_outs(out);
> +if (statistics) {
> +SyscallStats *entry;
> +g_mutex_lock();
> +entry = get_or_create_entry(num);
> +entry->calls++;
> +g_mutex_unlock();
> +} else {
> +g_autofree gchar *out = g_strdup_printf("syscall #%" PRIi64 "\n",
> num);
> +qemu_plugin_outs(out);
> +}
> }
>
> static void vcpu_syscall_ret(qemu_plugin_id_t id, unsigned int vcpu_idx,
> int64_t num, int64_t ret)
> +{
> +if (statistics) {
> +SyscallStats *entry;
> +
> +g_mutex_lock();
> +/* Should always return an existent entry. */
> +entry = get_or_create_entry(num);
> +if (ret < 0) {
> +entry->errors++;
> +}
> +g_mutex_unlock();
> +} else {
> +g_autofree gchar *out;
> +out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64
> "\n",
> +num, ret);
> +qemu_plugin_outs(out);
> +}
> +}
> +
> +static void print_entry(gpointer val, gpointer user_data)
> {
> g_autofree gchar *out;
> -out = g_strdup_printf("syscall #%" PRIi64 " returned -> %" PRIi64 "\n",
> -num, ret);
> +SyscallStats *entry = (SyscallStats *) val;
> +int64_t syscall_num = entry->num;
> +out = g_strdup_printf(
> +"%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
> +syscall_num, entry->calls, entry->errors);
> qemu_plugin_outs(out);
> }
>
> +static gint comp_func(gconstpointer ea, gconstpointer eb)
> +{
> +SyscallStats *ent_a = (SyscallStats *) ea;
> +SyscallStats *ent_b = (SyscallStats *) eb;
> +
> +return ent_a->calls > ent_b->calls ? -1 : 1;
> +}
> +
> /* *
> */
> +static void plugin_exit(qemu_plugin_id_t id, void *p)
> +{
> +if (!statistics) {
> +return;
> +}
> +
> +g_mutex_lock();
> +GList *entries = g_hash_table_get_values(statistics);
> +entries = g_list_sort(entries, comp_func);
> +qemu_plugin_outs("syscall no. calls errors\n");
>
> -static void plugin_exit(qemu_plugin_id_t id, void *p) {}
> +g_list_foreach(entries, print_entry, NULL);
> +
> +g_list_free(entries);
> +g_hash_table_destroy(statistics);
> +g_mutex_unlock();
> +}
>
> QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
> const qemu_info_t *info,
> int argc, char **argv)
> {
> +if (argc == 0) {
> +statistics = g_hash_table_new_full(NULL, g_direct_equal, NULL,
> g_free);
> +} else {
> +for (int i = 0; i < argc; i++) {
> +if (g_strcmp0(argv[i], "print") != 0) {
> +fprintf(stderr, "unsupported argument: %s\n", argv[i]);
> +return -1;
> +}
> +}
> +}
> +
> qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
> qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
> qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
--
Alex Bennée
