tests/plugin/insn.c

   1 /*
   2  * Copyright (C) 2018, Emilio G. Cota <cota@braap.org>
   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 #define MAX_CPUS 8 /* lets not go nuts */
  20
  21 typedef struct {
  22     uint64_t insn_count;
  23 } InstructionCount;
  24
  25 static InstructionCount counts[MAX_CPUS];
  26 static uint64_t inline_insn_count;
  27
  28 static bool do_inline;
  29 static bool do_size;
  30 static GArray *sizes;
  31
  32 typedef struct {
  33     char *match_string;
  34     uint64_t hits[MAX_CPUS];
  35     uint64_t last_hit[MAX_CPUS];
  36     uint64_t total_delta[MAX_CPUS];
  37     GPtrArray *history[MAX_CPUS];
  38 } Match;
  39
  40 static GArray *matches;
  41
  42 typedef struct {
  43     Match *match;
  44     uint64_t vaddr;
  45     uint64_t hits;
  46     char *disas;
  47 } Instruction;
  48
  49 static void vcpu_insn_exec_before(unsigned int cpu_index, void *udata)
  50 {
  51     unsigned int i = cpu_index % MAX_CPUS;
  52     InstructionCount *c = &counts[i];
  53
  54     c->insn_count++;
  55 }
  56
  57 static void vcpu_insn_matched_exec_before(unsigned int cpu_index, void *udata)
  58 {
  59     unsigned int i = cpu_index % MAX_CPUS;
  60     Instruction *insn = (Instruction *) udata;
  61     Match *match = insn->match;
  62     g_autoptr(GString) ts = g_string_new("");
  63
  64     insn->hits++;
  65     g_string_append_printf(ts, "0x%" PRIx64 ", '%s', %"PRId64 " hits",
  66                            insn->vaddr, insn->disas, insn->hits);
  67
  68     uint64_t icount = counts[i].insn_count;
  69     uint64_t delta = icount - match->last_hit[i];
  70
  71     match->hits[i]++;
  72     match->total_delta[i] += delta;
  73
  74     g_string_append_printf(ts,
  75                            ", %"PRId64" match hits, "
  76                            "Δ+%"PRId64 " since last match,"
  77                            " %"PRId64 " avg insns/match\n",
  78                            match->hits[i], delta,
  79                            match->total_delta[i] / match->hits[i]);
  80
  81     match->last_hit[i] = icount;
  82
  83     qemu_plugin_outs(ts->str);
  84
  85     g_ptr_array_add(match->history[i], insn);
  86 }
  87
  88 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
  89 {
  90     size_t n = qemu_plugin_tb_n_insns(tb);
  91     size_t i;
  92
  93     for (i = 0; i < n; i++) {
  94         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
  95
  96         if (do_inline) {
  97             qemu_plugin_register_vcpu_insn_exec_inline(
  98                 insn, QEMU_PLUGIN_INLINE_ADD_U64, &inline_insn_count, 1);
  99         } else {
 100             uint64_t vaddr = qemu_plugin_insn_vaddr(insn);
 101             qemu_plugin_register_vcpu_insn_exec_cb(
 102                 insn, vcpu_insn_exec_before, QEMU_PLUGIN_CB_NO_REGS,
 103                 GUINT_TO_POINTER(vaddr));
 104         }
 105
 106         if (do_size) {
 107             size_t sz = qemu_plugin_insn_size(insn);
 108             if (sz > sizes->len) {
 109                 g_array_set_size(sizes, sz);
 110             }
 111             unsigned long *cnt = &g_array_index(sizes, unsigned long, sz);
 112             (*cnt)++;
 113         }
 114
 115         /*
 116          * If we are tracking certain instructions we will need more
 117          * information about the instruction which we also need to
 118          * save if there is a hit.
 119          */
 120         if (matches) {
 121             char *insn_disas = qemu_plugin_insn_disas(insn);
 122             int j;
 123             for (j = 0; j < matches->len; j++) {
 124                 Match *m = &g_array_index(matches, Match, j);
 125                 if (g_str_has_prefix(insn_disas, m->match_string)) {
 126                     Instruction *rec = g_new0(Instruction, 1);
 127                     rec->disas = g_strdup(insn_disas);
 128                     rec->vaddr = qemu_plugin_insn_vaddr(insn);
 129                     rec->match = m;
 130                     qemu_plugin_register_vcpu_insn_exec_cb(
 131                         insn, vcpu_insn_matched_exec_before,
 132                         QEMU_PLUGIN_CB_NO_REGS, rec);
 133                 }
 134             }
 135             g_free(insn_disas);
 136         }
 137     }
 138 }
 139
 140 static void plugin_exit(qemu_plugin_id_t id, void *p)
 141 {
 142     g_autoptr(GString) out = g_string_new(NULL);
 143     int i;
 144
 145     if (do_size) {
 146         for (i = 0; i <= sizes->len; i++) {
 147             unsigned long *cnt = &g_array_index(sizes, unsigned long, i);
 148             if (*cnt) {
 149                 g_string_append_printf(out,
 150                                        "len %d bytes: %ld insns\n", i, *cnt);
 151             }
 152         }
 153     } else if (do_inline) {
 154         g_string_append_printf(out, "insns: %" PRIu64 "\n", inline_insn_count);
 155     } else {
 156         uint64_t total_insns = 0;
 157         for (i = 0; i < MAX_CPUS; i++) {
 158             InstructionCount *c = &counts[i];
 159             if (c->insn_count) {
 160                 g_string_append_printf(out, "cpu %d insns: %" PRIu64 "\n",
 161                                        i, c->insn_count);
 162                 total_insns += c->insn_count;
 163             }
 164         }
 165         g_string_append_printf(out, "total insns: %" PRIu64 "\n",
 166                                total_insns);
 167     }
 168     qemu_plugin_outs(out->str);
 169 }
 170
 171
 172 /* Add a match to the array of matches */
 173 static void parse_match(char *match)
 174 {
 175     Match new_match = { .match_string = match };
 176     int i;
 177     for (i = 0; i < MAX_CPUS; i++) {
 178         new_match.history[i] = g_ptr_array_new();
 179     }
 180     if (!matches) {
 181         matches = g_array_new(false, true, sizeof(Match));
 182     }
 183     g_array_append_val(matches, new_match);
 184 }
 185
 186 QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
 187                                            const qemu_info_t *info,
 188                                            int argc, char **argv)
 189 {
 190     for (int i = 0; i < argc; i++) {
 191         char *opt = argv[i];
 192         g_auto(GStrv) tokens = g_strsplit(opt, "=", 2);
 193         if (g_strcmp0(tokens[0], "inline") == 0) {
 194             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_inline)) {
 195                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
 196                 return -1;
 197             }
 198         } else if (g_strcmp0(tokens[0], "sizes") == 0) {
 199             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_size)) {
 200                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
 201                 return -1;
 202             }
 203         } else if (g_strcmp0(tokens[0], "match") == 0) {
 204             parse_match(tokens[1]);
 205         } else {
 206             fprintf(stderr, "option parsing failed: %s\n", opt);
 207             return -1;
 208         }
 209     }
 210
 211     if (do_size) {
 212         sizes = g_array_new(true, true, sizeof(unsigned long));
 213     }
 214
 215     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
 216     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
 217     return 0;
 218 }