tests/plugin/syscall.c

   1 /*
   2  * Copyright (C) 2020, Matthias Weckbecker <matthias@weckbecker.name>
   3  *
   4  * License: GNU GPL, version 2 or later.
   5  *   See the COPYING file in the top-level directory.
   6  */
   7 #include <inttypes.h>
   8 #include <assert.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12 #include <stdio.h>
  13 #include <glib.h>
  14
  15 #include <qemu-plugin.h>
  16
  17 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
  18
  19 typedef struct {
  20     int64_t num;
  21     int64_t calls;
  22     int64_t errors;
  23 } SyscallStats;
  24
  25 static GMutex lock;
  26 static GHashTable *statistics;
  27
  28 static SyscallStats *get_or_create_entry(int64_t num)
  29 {
  30     SyscallStats *entry =
  31         (SyscallStats *) g_hash_table_lookup(statistics, GINT_TO_POINTER(num));
  32
  33     if (!entry) {
  34         entry = g_new0(SyscallStats, 1);
  35         entry->num = num;
  36         g_hash_table_insert(statistics, GINT_TO_POINTER(num), (gpointer) entry);
  37     }
  38
  39     return entry;
  40 }
  41
  42 static void vcpu_syscall(qemu_plugin_id_t id, unsigned int vcpu_index,
  43                          int64_t num, uint64_t a1, uint64_t a2,
  44                          uint64_t a3, uint64_t a4, uint64_t a5,
  45                          uint64_t a6, uint64_t a7, uint64_t a8)
  46 {
  47     if (statistics) {
  48         SyscallStats *entry;
  49         g_mutex_lock(&lock);
  50         entry = get_or_create_entry(num);
  51         entry->calls++;
  52         g_mutex_unlock(&lock);
  53     } else {
  54         g_autofree gchar *out = g_strdup_printf("syscall #%" PRIi64 "\n", num);
  55         qemu_plugin_outs(out);
  56     }
  57 }
  58
  59 static void vcpu_syscall_ret(qemu_plugin_id_t id, unsigned int vcpu_idx,
  60                              int64_t num, int64_t ret)
  61 {
  62     if (statistics) {
  63         SyscallStats *entry;
  64
  65         g_mutex_lock(&lock);
  66         /* Should always return an existent entry. */
  67         entry = get_or_create_entry(num);
  68         if (ret < 0) {
  69             entry->errors++;
  70         }
  71         g_mutex_unlock(&lock);
  72     } else {
  73         g_autofree gchar *out = g_strdup_printf(
  74              "syscall #%" PRIi64 " returned -> %" PRIi64 "\n", num, ret);
  75         qemu_plugin_outs(out);
  76     }
  77 }
  78
  79 static void print_entry(gpointer val, gpointer user_data)
  80 {
  81     SyscallStats *entry = (SyscallStats *) val;
  82     int64_t syscall_num = entry->num;
  83     g_autofree gchar *out = g_strdup_printf(
  84         "%-13" PRIi64 "%-6" PRIi64 " %" PRIi64 "\n",
  85         syscall_num, entry->calls, entry->errors);
  86     qemu_plugin_outs(out);
  87 }
  88
  89 static gint comp_func(gconstpointer ea, gconstpointer eb)
  90 {
  91     SyscallStats *ent_a = (SyscallStats *) ea;
  92     SyscallStats *ent_b = (SyscallStats *) eb;
  93
  94     return ent_a->calls > ent_b->calls ? -1 : 1;
  95 }
  96
  97 /* ************************************************************************* */
  98 static void plugin_exit(qemu_plugin_id_t id, void *p)
  99 {
 100     if (!statistics) {
 101         return;
 102     }
 103
 104     g_mutex_lock(&lock);
 105     GList *entries = g_hash_table_get_values(statistics);
 106     entries = g_list_sort(entries, comp_func);
 107     qemu_plugin_outs("syscall no.  calls  errors\n");
 108
 109     g_list_foreach(entries, print_entry, NULL);
 110
 111     g_list_free(entries);
 112     g_hash_table_destroy(statistics);
 113     g_mutex_unlock(&lock);
 114 }
 115
 116 QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
 117                                            const qemu_info_t *info,
 118                                            int argc, char **argv)
 119 {
 120     bool do_print = false;
 121
 122     for (int i = 0; i < argc; i++) {
 123         char *opt = argv[i];
 124         g_autofree char **tokens = g_strsplit(opt, "=", 2);
 125
 126         if (g_strcmp0(tokens[0], "print") == 0) {
 127             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_print)) {
 128                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
 129             }
 130         } else {
 131             fprintf(stderr, "unsupported argument: %s\n", argv[i]);
 132             return -1;
 133         }
 134     }
 135
 136     if (!do_print) {
 137         statistics = g_hash_table_new_full(NULL, g_direct_equal, NULL, g_free);
 138     }
 139
 140     qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
 141     qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
 142     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
 143     return 0;
 144 }