plugins/api.c

   1 /*
   2  * QEMU Plugin API
   3  *
   4  * This provides the API that is available to the plugins to interact
   5  * with QEMU. We have to be careful not to expose internal details of
   6  * how QEMU works so we abstract out things like translation and
   7  * instructions to anonymous data types:
   8  *
   9  *  qemu_plugin_tb
  10  *  qemu_plugin_insn
  11  *
  12  * Which can then be passed back into the API to do additional things.
  13  * As such all the public functions in here are exported in
  14  * qemu-plugin.h.
  15  *
  16  * The general life-cycle of a plugin is:
  17  *
  18  *  - plugin is loaded, public qemu_plugin_install called
  19  *    - the install func registers callbacks for events
  20  *    - usually an atexit_cb is registered to dump info at the end
  21  *  - when a registered event occurs the plugin is called
  22  *     - some events pass additional info
  23  *     - during translation the plugin can decide to instrument any
  24  *       instruction
  25  *  - when QEMU exits all the registered atexit callbacks are called
  26  *
  27  * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
  28  * Copyright (C) 2019, Linaro
  29  *
  30  * License: GNU GPL, version 2 or later.
  31  *   See the COPYING file in the top-level directory.
  32  *
  33  * SPDX-License-Identifier: GPL-2.0-or-later
  34  *
  35  */
  36
  37 #include "qemu/osdep.h"
  38 #include "qemu/plugin.h"
  39 #include "cpu.h"
  40 #include "sysemu/sysemu.h"
  41 #include "tcg/tcg.h"
  42 #include "exec/exec-all.h"
  43 #include "disas/disas.h"
  44 #include "plugin.h"
  45 #ifndef CONFIG_USER_ONLY
  46 #include "qemu/plugin-memory.h"
  47 #include "hw/boards.h"
  48 #endif
  49 #include "trace/mem.h"
  50
  51 /* Uninstall and Reset handlers */
  52
  53 void qemu_plugin_uninstall(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
  54 {
  55     plugin_reset_uninstall(id, cb, false);
  56 }
  57
  58 void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
  59 {
  60     plugin_reset_uninstall(id, cb, true);
  61 }
  62
  63 /*
  64  * Plugin Register Functions
  65  *
  66  * This allows the plugin to register callbacks for various events
  67  * during the translation.
  68  */
  69
  70 void qemu_plugin_register_vcpu_init_cb(qemu_plugin_id_t id,
  71                                        qemu_plugin_vcpu_simple_cb_t cb)
  72 {
  73     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_INIT, cb);
  74 }
  75
  76 void qemu_plugin_register_vcpu_exit_cb(qemu_plugin_id_t id,
  77                                        qemu_plugin_vcpu_simple_cb_t cb)
  78 {
  79     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_EXIT, cb);
  80 }
  81
  82 void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
  83                                           qemu_plugin_vcpu_udata_cb_t cb,
  84                                           enum qemu_plugin_cb_flags flags,
  85                                           void *udata)
  86 {
  87     if (!tb->mem_only) {
  88         plugin_register_dyn_cb__udata(&tb->cbs[PLUGIN_CB_REGULAR],
  89                                       cb, flags, udata);
  90     }
  91 }
  92
  93 void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
  94                                               enum qemu_plugin_op op,
  95                                               void *ptr, uint64_t imm)
  96 {
  97     if (!tb->mem_only) {
  98         plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
  99     }
 100 }
 101
 102 void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
 103                                             qemu_plugin_vcpu_udata_cb_t cb,
 104                                             enum qemu_plugin_cb_flags flags,
 105                                             void *udata)
 106 {
 107     if (!insn->mem_only) {
 108         plugin_register_dyn_cb__udata(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR],
 109                                       cb, flags, udata);
 110     }
 111 }
 112
 113 void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
 114                                                 enum qemu_plugin_op op,
 115                                                 void *ptr, uint64_t imm)
 116 {
 117     if (!insn->mem_only) {
 118         plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
 119                                   0, op, ptr, imm);
 120     }
 121 }
 122
 123
 124 /*
 125  * We always plant memory instrumentation because they don't finalise until
 126  * after the operation has complete.
 127  */
 128 void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
 129                                       qemu_plugin_vcpu_mem_cb_t cb,
 130                                       enum qemu_plugin_cb_flags flags,
 131                                       enum qemu_plugin_mem_rw rw,
 132                                       void *udata)
 133 {
 134     plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
 135                                     cb, flags, rw, udata);
 136 }
 137
 138 void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
 139                                           enum qemu_plugin_mem_rw rw,
 140                                           enum qemu_plugin_op op, void *ptr,
 141                                           uint64_t imm)
 142 {
 143     plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
 144                               rw, op, ptr, imm);
 145 }
 146
 147 void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
 148                                            qemu_plugin_vcpu_tb_trans_cb_t cb)
 149 {
 150     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb);
 151 }
 152
 153 void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
 154                                           qemu_plugin_vcpu_syscall_cb_t cb)
 155 {
 156     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
 157 }
 158
 159 void
 160 qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
 161                                          qemu_plugin_vcpu_syscall_ret_cb_t cb)
 162 {
 163     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb);
 164 }
 165
 166 /*
 167  * Plugin Queries
 168  *
 169  * These are queries that the plugin can make to gauge information
 170  * from our opaque data types. We do not want to leak internal details
 171  * here just information useful to the plugin.
 172  */
 173
 174 /*
 175  * Translation block information:
 176  *
 177  * A plugin can query the virtual address of the start of the block
 178  * and the number of instructions in it. It can also get access to
 179  * each translated instruction.
 180  */
 181
 182 size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb)
 183 {
 184     return tb->n;
 185 }
 186
 187 uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb)
 188 {
 189     return tb->vaddr;
 190 }
 191
 192 struct qemu_plugin_insn *
 193 qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
 194 {
 195     struct qemu_plugin_insn *insn;
 196     if (unlikely(idx >= tb->n)) {
 197         return NULL;
 198     }
 199     insn = g_ptr_array_index(tb->insns, idx);
 200     insn->mem_only = tb->mem_only;
 201     return insn;
 202 }
 203
 204 /*
 205  * Instruction information
 206  *
 207  * These queries allow the plugin to retrieve information about each
 208  * instruction being translated.
 209  */
 210
 211 const void *qemu_plugin_insn_data(const struct qemu_plugin_insn *insn)
 212 {
 213     return insn->data->data;
 214 }
 215
 216 size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
 217 {
 218     return insn->data->len;
 219 }
 220
 221 uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
 222 {
 223     return insn->vaddr;
 224 }
 225
 226 void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
 227 {
 228     return insn->haddr;
 229 }
 230
 231 char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
 232 {
 233     CPUState *cpu = current_cpu;
 234     return plugin_disas(cpu, insn->vaddr, insn->data->len);
 235 }
 236
 237 /*
 238  * The memory queries allow the plugin to query information about a
 239  * memory access.
 240  */
 241
 242 unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info)
 243 {
 244     return info & TRACE_MEM_SZ_SHIFT_MASK;
 245 }
 246
 247 bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info)
 248 {
 249     return !!(info & TRACE_MEM_SE);
 250 }
 251
 252 bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info)
 253 {
 254     return !!(info & TRACE_MEM_BE);
 255 }
 256
 257 bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info)
 258 {
 259     return !!(info & TRACE_MEM_ST);
 260 }
 261
 262 /*
 263  * Virtual Memory queries
 264  */
 265
 266 #ifdef CONFIG_SOFTMMU
 267 static __thread struct qemu_plugin_hwaddr hwaddr_info;
 268
 269 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
 270                                                   uint64_t vaddr)
 271 {
 272     CPUState *cpu = current_cpu;
 273     unsigned int mmu_idx = info >> TRACE_MEM_MMU_SHIFT;
 274     hwaddr_info.is_store = info & TRACE_MEM_ST;
 275
 276     if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx,
 277                            info & TRACE_MEM_ST, &hwaddr_info)) {
 278         error_report("invalid use of qemu_plugin_get_hwaddr");
 279         return NULL;
 280     }
 281
 282     return &hwaddr_info;
 283 }
 284 #else
 285 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
 286                                                   uint64_t vaddr)
 287 {
 288     return NULL;
 289 }
 290 #endif
 291
 292 bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr)
 293 {
 294 #ifdef CONFIG_SOFTMMU
 295     return haddr->is_io;
 296 #else
 297     return false;
 298 #endif
 299 }
 300
 301 uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr)
 302 {
 303 #ifdef CONFIG_SOFTMMU
 304     if (haddr) {
 305         if (!haddr->is_io) {
 306             ram_addr_t ram_addr = qemu_ram_addr_from_host((void *) haddr->v.ram.hostaddr);
 307             if (ram_addr == RAM_ADDR_INVALID) {
 308                 error_report("Bad ram pointer %"PRIx64"", haddr->v.ram.hostaddr);
 309                 abort();
 310             }
 311             return ram_addr;
 312         } else {
 313             return haddr->v.io.offset;
 314         }
 315     }
 316 #endif
 317     return 0;
 318 }
 319
 320 const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
 321 {
 322 #ifdef CONFIG_SOFTMMU
 323     if (h && h->is_io) {
 324         MemoryRegionSection *mrs = h->v.io.section;
 325         if (!mrs->mr->name) {
 326             unsigned long maddr = 0xffffffff & (uintptr_t) mrs->mr;
 327             g_autofree char *temp = g_strdup_printf("anon%08lx", maddr);
 328             return g_intern_string(temp);
 329         } else {
 330             return g_intern_string(mrs->mr->name);
 331         }
 332     } else {
 333         return g_intern_static_string("RAM");
 334     }
 335 #else
 336     return g_intern_static_string("Invalid");
 337 #endif
 338 }
 339
 340 /*
 341  * Queries to the number and potential maximum number of vCPUs there
 342  * will be. This helps the plugin dimension per-vcpu arrays.
 343  */
 344
 345 #ifndef CONFIG_USER_ONLY
 346 static MachineState * get_ms(void)
 347 {
 348     return MACHINE(qdev_get_machine());
 349 }
 350 #endif
 351
 352 int qemu_plugin_n_vcpus(void)
 353 {
 354 #ifdef CONFIG_USER_ONLY
 355     return -1;
 356 #else
 357     return get_ms()->smp.cpus;
 358 #endif
 359 }
 360
 361 int qemu_plugin_n_max_vcpus(void)
 362 {
 363 #ifdef CONFIG_USER_ONLY
 364     return -1;
 365 #else
 366     return get_ms()->smp.max_cpus;
 367 #endif
 368 }
 369
 370 /*
 371  * Plugin output
 372  */
 373 void qemu_plugin_outs(const char *string)
 374 {
 375     qemu_log_mask(CPU_LOG_PLUGIN, "%s", string);
 376 }