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 last_pc;
  23     uint64_t insn_count;
  24 } InstructionCount;
  25
  26 static InstructionCount counts[MAX_CPUS];
  27 static uint64_t inline_insn_count;
  28
  29 static bool do_inline;
  30 static bool do_size;
  31 static GArray *sizes;
  32
  33 typedef struct {
  34     char *match_string;
  35     uint64_t hits[MAX_CPUS];
  36     uint64_t last_hit[MAX_CPUS];
  37     uint64_t total_delta[MAX_CPUS];
  38     GPtrArray *history[MAX_CPUS];
  39 } Match;
  40
  41 static GArray *matches;
  42
  43 typedef struct {
  44     Match *match;
  45     uint64_t vaddr;
  46     uint64_t hits;
  47     char *disas;
  48 } Instruction;
  49
  50 static void vcpu_insn_exec_before(unsigned int cpu_index, void *udata)
  51 {
  52     unsigned int i = cpu_index % MAX_CPUS;
  53     InstructionCount *c = &counts[i];
  54     uint64_t this_pc = GPOINTER_TO_UINT(udata);
  55     if (this_pc == c->last_pc) {
  56         g_autofree gchar *out = g_strdup_printf("detected repeat execution @ 0x%"
  57                                                 PRIx64 "\n", this_pc);
  58         qemu_plugin_outs(out);
  59     }
  60     c->last_pc = this_pc;
  61     c->insn_count++;
  62 }
  63
  64 static void vcpu_insn_matched_exec_before(unsigned int cpu_index, void *udata)
  65 {
  66     unsigned int i = cpu_index % MAX_CPUS;
  67     Instruction *insn = (Instruction *) udata;
  68     Match *match = insn->match;
  69     g_autoptr(GString) ts = g_string_new("");
  70
  71     insn->hits++;
  72     g_string_append_printf(ts, "0x%" PRIx64 ", '%s', %"PRId64 " hits",
  73                            insn->vaddr, insn->disas, insn->hits);
  74
  75     uint64_t icount = counts[i].insn_count;
  76     uint64_t delta = icount - match->last_hit[i];
  77
  78     match->hits[i]++;
  79     match->total_delta[i] += delta;
  80
  81     g_string_append_printf(ts,
  82                            ", %"PRId64" match hits, "
  83                            "Δ+%"PRId64 " since last match,"
  84                            " %"PRId64 " avg insns/match\n",
  85                            match->hits[i], delta,
  86                            match->total_delta[i] / match->hits[i]);
  87
  88     match->last_hit[i] = icount;
  89
  90     qemu_plugin_outs(ts->str);
  91
  92     g_ptr_array_add(match->history[i], insn);
  93 }
  94
  95 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
  96 {
  97     size_t n = qemu_plugin_tb_n_insns(tb);
  98     size_t i;
  99
 100     for (i = 0; i < n; i++) {
 101         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
 102
 103         if (do_inline) {
 104             qemu_plugin_register_vcpu_insn_exec_inline(
 105                 insn, QEMU_PLUGIN_INLINE_ADD_U64, &inline_insn_count, 1);
 106         } else {
 107             uint64_t vaddr = qemu_plugin_insn_vaddr(insn);
 108             qemu_plugin_register_vcpu_insn_exec_cb(
 109                 insn, vcpu_insn_exec_before, QEMU_PLUGIN_CB_NO_REGS,
 110                 GUINT_TO_POINTER(vaddr));
 111         }
 112
 113         if (do_size) {
 114             size_t sz = qemu_plugin_insn_size(insn);
 115             if (sz > sizes->len) {
 116                 g_array_set_size(sizes, sz);
 117             }
 118             unsigned long *cnt = &g_array_index(sizes, unsigned long, sz);
 119             (*cnt)++;
 120         }
 121
 122         /*
 123          * If we are tracking certain instructions we will need more
 124          * information about the instruction which we also need to
 125          * save if there is a hit.
 126          */
 127         if (matches) {
 128             char *insn_disas = qemu_plugin_insn_disas(insn);
 129             int j;
 130             for (j = 0; j < matches->len; j++) {
 131                 Match *m = &g_array_index(matches, Match, j);
 132                 if (g_str_has_prefix(insn_disas, m->match_string)) {
 133                     Instruction *rec = g_new0(Instruction, 1);
 134                     rec->disas = g_strdup(insn_disas);
 135                     rec->vaddr = qemu_plugin_insn_vaddr(insn);
 136                     rec->match = m;
 137                     qemu_plugin_register_vcpu_insn_exec_cb(
 138                         insn, vcpu_insn_matched_exec_before,
 139                         QEMU_PLUGIN_CB_NO_REGS, rec);
 140                 }
 141             }
 142             g_free(insn_disas);
 143         }
 144     }
 145 }
 146
 147 static void plugin_exit(qemu_plugin_id_t id, void *p)
 148 {
 149     g_autoptr(GString) out = g_string_new(NULL);
 150     int i;
 151
 152     if (do_size) {
 153         for (i = 0; i <= sizes->len; i++) {
 154             unsigned long *cnt = &g_array_index(sizes, unsigned long, i);
 155             if (*cnt) {
 156                 g_string_append_printf(out,
 157                                        "len %d bytes: %ld insns\n", i, *cnt);
 158             }
 159         }
 160     } else if (do_inline) {
 161         g_string_append_printf(out, "insns: %" PRIu64 "\n", inline_insn_count);
 162     } else {
 163         uint64_t total_insns = 0;
 164         for (i = 0; i < MAX_CPUS; i++) {
 165             InstructionCount *c = &counts[i];
 166             if (c->insn_count) {
 167                 g_string_append_printf(out, "cpu %d insns: %" PRIu64 "\n",
 168                                        i, c->insn_count);
 169                 total_insns += c->insn_count;
 170             }
 171         }
 172         g_string_append_printf(out, "total insns: %" PRIu64 "\n",
 173                                total_insns);
 174     }
 175     qemu_plugin_outs(out->str);
 176 }
 177
 178
 179 /* Add a match to the array of matches */
 180 static void parse_match(char *match)
 181 {
 182     Match new_match = { .match_string = match };
 183     int i;
 184     for (i = 0; i < MAX_CPUS; i++) {
 185         new_match.history[i] = g_ptr_array_new();
 186     }
 187     if (!matches) {
 188         matches = g_array_new(false, true, sizeof(Match));
 189     }
 190     g_array_append_val(matches, new_match);
 191 }
 192
 193 QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
 194                                            const qemu_info_t *info,
 195                                            int argc, char **argv)
 196 {
 197     for (int i = 0; i < argc; i++) {
 198         char *opt = argv[i];
 199         g_autofree char **tokens = g_strsplit(opt, "=", 2);
 200         if (g_strcmp0(tokens[0], "inline") == 0) {
 201             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_inline)) {
 202                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
 203                 return -1;
 204             }
 205         } else if (g_strcmp0(tokens[0], "sizes") == 0) {
 206             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_size)) {
 207                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
 208                 return -1;
 209             }
 210         } else if (g_strcmp0(tokens[0], "match") == 0) {
 211             parse_match(tokens[1]);
 212         } else {
 213             fprintf(stderr, "option parsing failed: %s\n", opt);
 214             return -1;
 215         }
 216     }
 217
 218     if (do_size) {
 219         sizes = g_array_new(true, true, sizeof(unsigned long));
 220     }
 221
 222     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
 223     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
 224     return 0;
 225 }