contrib/plugins/hotpages.c

   1 /*
   2  * Copyright (C) 2019, Alex Bennée <alex.bennee@linaro.org>
   3  *
   4  * Hot Pages - show which pages saw the most memory accesses.
   5  *
   6  * License: GNU GPL, version 2 or later.
   7  *   See the COPYING file in the top-level directory.
   8  */
   9
  10 #include <inttypes.h>
  11 #include <assert.h>
  12 #include <stdlib.h>
  13 #include <inttypes.h>
  14 #include <string.h>
  15 #include <unistd.h>
  16 #include <stdio.h>
  17 #include <glib.h>
  18
  19 #include <qemu-plugin.h>
  20
  21 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
  22
  23 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  24
  25 static uint64_t page_size = 4096;
  26 static uint64_t page_mask;
  27 static int limit = 50;
  28 static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
  29 static bool track_io;
  30
  31 enum sort_type {
  32     SORT_RW = 0,
  33     SORT_R,
  34     SORT_W,
  35     SORT_A
  36 };
  37
  38 static int sort_by = SORT_RW;
  39
  40 typedef struct {
  41     uint64_t page_address;
  42     int cpu_read;
  43     int cpu_write;
  44     uint64_t reads;
  45     uint64_t writes;
  46 } PageCounters;
  47
  48 static GMutex lock;
  49 static GHashTable *pages;
  50
  51 static gint cmp_access_count(gconstpointer a, gconstpointer b)
  52 {
  53     PageCounters *ea = (PageCounters *) a;
  54     PageCounters *eb = (PageCounters *) b;
  55     int r;
  56     switch (sort_by) {
  57     case SORT_RW:
  58         r = (ea->reads + ea->writes) > (eb->reads + eb->writes) ? -1 : 1;
  59         break;
  60     case SORT_R:
  61         r = ea->reads > eb->reads ? -1 : 1;
  62         break;
  63     case SORT_W:
  64         r = ea->writes > eb->writes ? -1 : 1;
  65         break;
  66     case SORT_A:
  67         r = ea->page_address > eb->page_address ? -1 : 1;
  68         break;
  69     default:
  70         g_assert_not_reached();
  71     }
  72     return r;
  73 }
  74
  75
  76 static void plugin_exit(qemu_plugin_id_t id, void *p)
  77 {
  78     g_autoptr(GString) report = g_string_new("Addr, RCPUs, Reads, WCPUs, Writes\n");
  79     int i;
  80     GList *counts;
  81
  82     counts = g_hash_table_get_values(pages);
  83     if (counts && g_list_next(counts)) {
  84         GList *it;
  85
  86         it = g_list_sort(counts, cmp_access_count);
  87
  88         for (i = 0; i < limit && it->next; i++, it = it->next) {
  89             PageCounters *rec = (PageCounters *) it->data;
  90             g_string_append_printf(report,
  91                                    "0x%016"PRIx64", 0x%04x, %"PRId64
  92                                    ", 0x%04x, %"PRId64"\n",
  93                                    rec->page_address,
  94                                    rec->cpu_read, rec->reads,
  95                                    rec->cpu_write, rec->writes);
  96         }
  97         g_list_free(it);
  98     }
  99
 100     qemu_plugin_outs(report->str);
 101 }
 102
 103 static void plugin_init(void)
 104 {
 105     page_mask = (page_size - 1);
 106     pages = g_hash_table_new(NULL, g_direct_equal);
 107 }
 108
 109 static void vcpu_haddr(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
 110                        uint64_t vaddr, void *udata)
 111 {
 112     struct qemu_plugin_hwaddr *hwaddr = qemu_plugin_get_hwaddr(meminfo, vaddr);
 113     uint64_t page;
 114     PageCounters *count;
 115
 116     /* We only get a hwaddr for system emulation */
 117     if (track_io) {
 118         if (hwaddr && qemu_plugin_hwaddr_is_io(hwaddr)) {
 119             page = vaddr;
 120         } else {
 121             return;
 122         }
 123     } else {
 124         if (hwaddr && !qemu_plugin_hwaddr_is_io(hwaddr)) {
 125             page = (uint64_t) qemu_plugin_hwaddr_device_offset(hwaddr);
 126         } else {
 127             page = vaddr;
 128         }
 129     }
 130     page &= ~page_mask;
 131
 132     g_mutex_lock(&lock);
 133     count = (PageCounters *) g_hash_table_lookup(pages, GUINT_TO_POINTER(page));
 134
 135     if (!count) {
 136         count = g_new0(PageCounters, 1);
 137         count->page_address = page;
 138         g_hash_table_insert(pages, GUINT_TO_POINTER(page), (gpointer) count);
 139     }
 140     if (qemu_plugin_mem_is_store(meminfo)) {
 141         count->writes++;
 142         count->cpu_write |= (1 << cpu_index);
 143     } else {
 144         count->reads++;
 145         count->cpu_read |= (1 << cpu_index);
 146     }
 147
 148     g_mutex_unlock(&lock);
 149 }
 150
 151 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
 152 {
 153     size_t n = qemu_plugin_tb_n_insns(tb);
 154     size_t i;
 155
 156     for (i = 0; i < n; i++) {
 157         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
 158         qemu_plugin_register_vcpu_mem_cb(insn, vcpu_haddr,
 159                                          QEMU_PLUGIN_CB_NO_REGS,
 160                                          rw, NULL);
 161     }
 162 }
 163
 164 QEMU_PLUGIN_EXPORT
 165 int qemu_plugin_install(qemu_plugin_id_t id, const qemu_info_t *info,
 166                         int argc, char **argv)
 167 {
 168     int i;
 169
 170     for (i = 0; i < argc; i++) {
 171         char *opt = argv[i];
 172         if (g_strcmp0(opt, "reads") == 0) {
 173             sort_by = SORT_R;
 174         } else if (g_strcmp0(opt, "writes") == 0) {
 175             sort_by = SORT_W;
 176         } else if (g_strcmp0(opt, "address") == 0) {
 177             sort_by = SORT_A;
 178         } else if (g_strcmp0(opt, "io") == 0) {
 179             track_io = true;
 180         } else if (g_str_has_prefix(opt, "pagesize=")) {
 181             page_size = g_ascii_strtoull(opt + 9, NULL, 10);
 182         } else {
 183             fprintf(stderr, "option parsing failed: %s\n", opt);
 184             return -1;
 185         }
 186     }
 187
 188     plugin_init();
 189
 190     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
 191     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
 192     return 0;
 193 }