contrib/plugins/hwprofile.c

   1 /*
   2  * Copyright (C) 2020, Alex Bennée <alex.bennee@linaro.org>
   3  *
   4  * HW Profile - breakdown access patterns for IO to devices
   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 typedef struct {
  26     uint64_t cpu_read;
  27     uint64_t cpu_write;
  28     uint64_t reads;
  29     uint64_t writes;
  30 } IOCounts;
  31
  32 typedef struct {
  33     uint64_t off_or_pc;
  34     IOCounts counts;
  35 } IOLocationCounts;
  36
  37 typedef struct {
  38     const char *name;
  39     uint64_t   base;
  40     IOCounts   totals;
  41     GHashTable *detail;
  42 } DeviceCounts;
  43
  44 static GMutex lock;
  45 static GHashTable *devices;
  46
  47 /* track the access pattern to a piece of HW */
  48 static bool pattern;
  49 /* track the source address of access to HW */
  50 static bool source;
  51 /* track only matched regions of HW */
  52 static bool check_match;
  53 static gchar **matches;
  54
  55 static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
  56
  57 static inline bool track_reads(void)
  58 {
  59     return rw == QEMU_PLUGIN_MEM_RW || rw == QEMU_PLUGIN_MEM_R;
  60 }
  61
  62 static inline bool track_writes(void)
  63 {
  64     return rw == QEMU_PLUGIN_MEM_RW || rw == QEMU_PLUGIN_MEM_W;
  65 }
  66
  67 static void plugin_init(void)
  68 {
  69     devices = g_hash_table_new(NULL, NULL);
  70 }
  71
  72 static gint sort_cmp(gconstpointer a, gconstpointer b)
  73 {
  74     DeviceCounts *ea = (DeviceCounts *) a;
  75     DeviceCounts *eb = (DeviceCounts *) b;
  76     return ea->totals.reads + ea->totals.writes >
  77            eb->totals.reads + eb->totals.writes ? -1 : 1;
  78 }
  79
  80 static gint sort_loc(gconstpointer a, gconstpointer b)
  81 {
  82     IOLocationCounts *ea = (IOLocationCounts *) a;
  83     IOLocationCounts *eb = (IOLocationCounts *) b;
  84     return ea->off_or_pc > eb->off_or_pc;
  85 }
  86
  87 static void fmt_iocount_record(GString *s, IOCounts *rec)
  88 {
  89     if (track_reads()) {
  90         g_string_append_printf(s, ", %"PRIx64", %"PRId64,
  91                                rec->cpu_read, rec->reads);
  92     }
  93     if (track_writes()) {
  94         g_string_append_printf(s, ", %"PRIx64", %"PRId64,
  95                                rec->cpu_write, rec->writes);
  96     }
  97 }
  98
  99 static void fmt_dev_record(GString *s, DeviceCounts *rec)
 100 {
 101     g_string_append_printf(s, "%s, 0x%"PRIx64,
 102                            rec->name, rec->base);
 103     fmt_iocount_record(s, &rec->totals);
 104     g_string_append_c(s, '\n');
 105 }
 106
 107 static void plugin_exit(qemu_plugin_id_t id, void *p)
 108 {
 109     g_autoptr(GString) report = g_string_new("");
 110     GList *counts;
 111
 112     if (!(pattern || source)) {
 113         g_string_printf(report, "Device, Address");
 114         if (track_reads()) {
 115             g_string_append_printf(report, ", RCPUs, Reads");
 116         }
 117         if (track_writes()) {
 118             g_string_append_printf(report, ",  WCPUs, Writes");
 119         }
 120         g_string_append_c(report, '\n');
 121     }
 122
 123     counts = g_hash_table_get_values(devices);
 124     if (counts && g_list_next(counts)) {
 125         GList *it;
 126
 127         it = g_list_sort(counts, sort_cmp);
 128
 129         while (it) {
 130             DeviceCounts *rec = (DeviceCounts *) it->data;
 131             if (rec->detail) {
 132                 GList *accesses = g_hash_table_get_values(rec->detail);
 133                 GList *io_it = g_list_sort(accesses, sort_loc);
 134                 const char *prefix = pattern ? "off" : "pc";
 135                 g_string_append_printf(report, "%s @ 0x%"PRIx64"\n",
 136                                        rec->name, rec->base);
 137                 while (io_it) {
 138                     IOLocationCounts *loc = (IOLocationCounts *) io_it->data;
 139                     g_string_append_printf(report, "  %s:%08"PRIx64,
 140                                            prefix, loc->off_or_pc);
 141                     fmt_iocount_record(report, &loc->counts);
 142                     g_string_append_c(report, '\n');
 143                     io_it = io_it->next;
 144                 }
 145             } else {
 146                 fmt_dev_record(report, rec);
 147             }
 148             it = it->next;
 149         };
 150         g_list_free(it);
 151     }
 152
 153     qemu_plugin_outs(report->str);
 154 }
 155
 156 static DeviceCounts *new_count(const char *name, uint64_t base)
 157 {
 158     DeviceCounts *count = g_new0(DeviceCounts, 1);
 159     count->name = name;
 160     count->base = base;
 161     if (pattern || source) {
 162         count->detail = g_hash_table_new(NULL, NULL);
 163     }
 164     g_hash_table_insert(devices, (gpointer) name, count);
 165     return count;
 166 }
 167
 168 static IOLocationCounts *new_location(GHashTable *table, uint64_t off_or_pc)
 169 {
 170     IOLocationCounts *loc = g_new0(IOLocationCounts, 1);
 171     loc->off_or_pc = off_or_pc;
 172     g_hash_table_insert(table, (gpointer) off_or_pc, loc);
 173     return loc;
 174 }
 175
 176 static void hwprofile_match_hit(DeviceCounts *rec, uint64_t off)
 177 {
 178     g_autoptr(GString) report = g_string_new("hwprofile: match @ offset");
 179     g_string_append_printf(report, "%"PRIx64", previous hits\n", off);
 180     fmt_dev_record(report, rec);
 181     qemu_plugin_outs(report->str);
 182 }
 183
 184 static void inc_count(IOCounts *count, bool is_write, unsigned int cpu_index)
 185 {
 186     if (is_write) {
 187         count->writes++;
 188         count->cpu_write |= (1 << cpu_index);
 189     } else {
 190         count->reads++;
 191         count->cpu_read |= (1 << cpu_index);
 192     }
 193 }
 194
 195 static void vcpu_haddr(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
 196                        uint64_t vaddr, void *udata)
 197 {
 198     struct qemu_plugin_hwaddr *hwaddr = qemu_plugin_get_hwaddr(meminfo, vaddr);
 199
 200     if (!hwaddr || !qemu_plugin_hwaddr_is_io(hwaddr)) {
 201         return;
 202     } else {
 203         const char *name = qemu_plugin_hwaddr_device_name(hwaddr);
 204         uint64_t off = qemu_plugin_hwaddr_device_offset(hwaddr);
 205         bool is_write = qemu_plugin_mem_is_store(meminfo);
 206         DeviceCounts *counts;
 207
 208         g_mutex_lock(&lock);
 209         counts = (DeviceCounts *) g_hash_table_lookup(devices, name);
 210
 211         if (!counts) {
 212             uint64_t base = vaddr - off;
 213             counts = new_count(name, base);
 214         }
 215
 216         if (check_match) {
 217             if (g_strv_contains((const char * const *)matches, counts->name)) {
 218                 hwprofile_match_hit(counts, off);
 219                 inc_count(&counts->totals, is_write, cpu_index);
 220             }
 221         } else {
 222             inc_count(&counts->totals, is_write, cpu_index);
 223         }
 224
 225         /* either track offsets or source of access */
 226         if (source) {
 227             off = (uint64_t) udata;
 228         }
 229
 230         if (pattern || source) {
 231             IOLocationCounts *io_count = g_hash_table_lookup(counts->detail,
 232                                                              (gpointer) off);
 233             if (!io_count) {
 234                 io_count = new_location(counts->detail, off);
 235             }
 236             inc_count(&io_count->counts, is_write, cpu_index);
 237         }
 238
 239         g_mutex_unlock(&lock);
 240     }
 241 }
 242
 243 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
 244 {
 245     size_t n = qemu_plugin_tb_n_insns(tb);
 246     size_t i;
 247
 248     for (i = 0; i < n; i++) {
 249         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
 250         gpointer udata = (gpointer) (source ? qemu_plugin_insn_vaddr(insn) : 0);
 251         qemu_plugin_register_vcpu_mem_cb(insn, vcpu_haddr,
 252                                          QEMU_PLUGIN_CB_NO_REGS,
 253                                          rw, udata);
 254     }
 255 }
 256
 257 QEMU_PLUGIN_EXPORT
 258 int qemu_plugin_install(qemu_plugin_id_t id, const qemu_info_t *info,
 259                         int argc, char **argv)
 260 {
 261     int i;
 262
 263     for (i = 0; i < argc; i++) {
 264         char *opt = argv[i];
 265         if (g_strcmp0(opt, "read") == 0) {
 266             rw = QEMU_PLUGIN_MEM_R;
 267         } else if (g_strcmp0(opt, "write") == 0) {
 268             rw = QEMU_PLUGIN_MEM_W;
 269         } else if (g_strcmp0(opt, "pattern") == 0) {
 270             pattern = true;
 271         } else if (g_strcmp0(opt, "source") == 0) {
 272             source = true;
 273         } else if (g_str_has_prefix(opt, "match")) {
 274             gchar **parts = g_strsplit(opt, "=", 2);
 275             check_match = true;
 276             matches = g_strsplit(parts[1], ",", -1);
 277             g_strfreev(parts);
 278         } else {
 279             fprintf(stderr, "option parsing failed: %s\n", opt);
 280             return -1;
 281         }
 282     }
 283
 284     if (source && pattern) {
 285         fprintf(stderr, "can only currently track either source or pattern.\n");
 286         return -1;
 287     }
 288
 289     if (!info->system_emulation) {
 290         fprintf(stderr, "hwprofile: plugin only useful for system emulation\n");
 291         return -1;
 292     }
 293
 294     /* Just warn about overflow */
 295     if (info->system.smp_vcpus > 64 ||
 296         info->system.max_vcpus > 64) {
 297         fprintf(stderr, "hwprofile: can only track up to 64 CPUs\n");
 298     }
 299
 300     plugin_init();
 301
 302     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
 303     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
 304     return 0;
 305 }