qemu

insn.c (7017B)

---

 /*
  * Copyright (C) 2018, Emilio G. Cota <cota@braap.org>
  *
  * License: GNU GPL, version 2 or later.
  *   See the COPYING file in the top-level directory.
  */
 #include <inttypes.h>
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <glib.h>
 
 #include <qemu-plugin.h>
 
 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
 
 #define MAX_CPUS 8 /* lets not go nuts */
 
 typedef struct {
     uint64_t last_pc;
     uint64_t insn_count;
 } InstructionCount;
 
 static InstructionCount counts[MAX_CPUS];
 static uint64_t inline_insn_count;
 
 static bool do_inline;
 static bool do_size;
 static GArray *sizes;
 
 typedef struct {
     char *match_string;
     uint64_t hits[MAX_CPUS];
     uint64_t last_hit[MAX_CPUS];
     uint64_t total_delta[MAX_CPUS];
     GPtrArray *history[MAX_CPUS];
 } Match;
 
 static GArray *matches;
 
 typedef struct {
     Match *match;
     uint64_t vaddr;
     uint64_t hits;
     char *disas;
 } Instruction;
 
 static void vcpu_insn_exec_before(unsigned int cpu_index, void *udata)
 {
     unsigned int i = cpu_index % MAX_CPUS;
     InstructionCount *c = &counts[i];
     uint64_t this_pc = GPOINTER_TO_UINT(udata);
     if (this_pc == c->last_pc) {
         g_autofree gchar *out = g_strdup_printf("detected repeat execution @ 0x%"
                                                 PRIx64 "\n", this_pc);
         qemu_plugin_outs(out);
     }
     c->last_pc = this_pc;
     c->insn_count++;
 }
 
 static void vcpu_insn_matched_exec_before(unsigned int cpu_index, void *udata)
 {
     unsigned int i = cpu_index % MAX_CPUS;
     Instruction *insn = (Instruction *) udata;
     Match *match = insn->match;
     g_autoptr(GString) ts = g_string_new("");
 
     insn->hits++;
     g_string_append_printf(ts, "0x%" PRIx64 ", '%s', %"PRId64 " hits",
                            insn->vaddr, insn->disas, insn->hits);
 
     uint64_t icount = counts[i].insn_count;
     uint64_t delta = icount - match->last_hit[i];
 
     match->hits[i]++;
     match->total_delta[i] += delta;
 
     g_string_append_printf(ts,
                            ", %"PRId64" match hits, "
                            "Δ+%"PRId64 " since last match,"
                            " %"PRId64 " avg insns/match\n",
                            match->hits[i], delta,
                            match->total_delta[i] / match->hits[i]);
 
     match->last_hit[i] = icount;
 
     qemu_plugin_outs(ts->str);
 
     g_ptr_array_add(match->history[i], insn);
 }
 
 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
 {
     size_t n = qemu_plugin_tb_n_insns(tb);
     size_t i;
 
     for (i = 0; i < n; i++) {
         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
 
         if (do_inline) {
             qemu_plugin_register_vcpu_insn_exec_inline(
                 insn, QEMU_PLUGIN_INLINE_ADD_U64, &inline_insn_count, 1);
         } else {
             uint64_t vaddr = qemu_plugin_insn_vaddr(insn);
             qemu_plugin_register_vcpu_insn_exec_cb(
                 insn, vcpu_insn_exec_before, QEMU_PLUGIN_CB_NO_REGS,
                 GUINT_TO_POINTER(vaddr));
         }
 
         if (do_size) {
             size_t sz = qemu_plugin_insn_size(insn);
             if (sz > sizes->len) {
                 g_array_set_size(sizes, sz);
             }
             unsigned long *cnt = &g_array_index(sizes, unsigned long, sz);
             (*cnt)++;
         }
 
         /*
          * If we are tracking certain instructions we will need more
          * information about the instruction which we also need to
          * save if there is a hit.
          */
         if (matches) {
             char *insn_disas = qemu_plugin_insn_disas(insn);
             int j;
             for (j = 0; j < matches->len; j++) {
                 Match *m = &g_array_index(matches, Match, j);
                 if (g_str_has_prefix(insn_disas, m->match_string)) {
                     Instruction *rec = g_new0(Instruction, 1);
                     rec->disas = g_strdup(insn_disas);
                     rec->vaddr = qemu_plugin_insn_vaddr(insn);
                     rec->match = m;
                     qemu_plugin_register_vcpu_insn_exec_cb(
                         insn, vcpu_insn_matched_exec_before,
                         QEMU_PLUGIN_CB_NO_REGS, rec);
                 }
             }
             g_free(insn_disas);
         }
     }
 }
 
 static void plugin_exit(qemu_plugin_id_t id, void *p)
 {
     g_autoptr(GString) out = g_string_new(NULL);
     int i;
 
     if (do_size) {
         for (i = 0; i <= sizes->len; i++) {
             unsigned long *cnt = &g_array_index(sizes, unsigned long, i);
             if (*cnt) {
                 g_string_append_printf(out,
                                        "len %d bytes: %ld insns\n", i, *cnt);
             }
         }
     } else if (do_inline) {
         g_string_append_printf(out, "insns: %" PRIu64 "\n", inline_insn_count);
     } else {
         uint64_t total_insns = 0;
         for (i = 0; i < MAX_CPUS; i++) {
             InstructionCount *c = &counts[i];
             if (c->insn_count) {
                 g_string_append_printf(out, "cpu %d insns: %" PRIu64 "\n",
                                        i, c->insn_count);
                 total_insns += c->insn_count;
             }
         }
         g_string_append_printf(out, "total insns: %" PRIu64 "\n",
                                total_insns);
     }
     qemu_plugin_outs(out->str);
 }
 
 
 /* Add a match to the array of matches */
 static void parse_match(char *match)
 {
     Match new_match = { .match_string = match };
     int i;
     for (i = 0; i < MAX_CPUS; i++) {
         new_match.history[i] = g_ptr_array_new();
     }
     if (!matches) {
         matches = g_array_new(false, true, sizeof(Match));
     }
     g_array_append_val(matches, new_match);
 }
 
 QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
                                            const qemu_info_t *info,
                                            int argc, char **argv)
 {
     for (int i = 0; i < argc; i++) {
         char *opt = argv[i];
         g_autofree char **tokens = g_strsplit(opt, "=", 2);
         if (g_strcmp0(tokens[0], "inline") == 0) {
             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_inline)) {
                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
                 return -1;
             }
         } else if (g_strcmp0(tokens[0], "sizes") == 0) {
             if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_size)) {
                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
                 return -1;
             }
         } else if (g_strcmp0(tokens[0], "match") == 0) {
             parse_match(tokens[1]);
         } else {
             fprintf(stderr, "option parsing failed: %s\n", opt);
             return -1;
         }
     }
 
     if (do_size) {
         sizes = g_array_new(true, true, sizeof(unsigned long));
     }
 
     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
     return 0;
 }