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     plugin_register_dyn_cb__udata(&tb->cbs[PLUGIN_CB_REGULAR],
  88                                   cb, flags, udata);
  89 }
  90
  91 void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
  92                                               enum qemu_plugin_op op,
  93                                               void *ptr, uint64_t imm)
  94 {
  95     plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
  96 }
  97
  98 void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
  99                                             qemu_plugin_vcpu_udata_cb_t cb,
 100                                             enum qemu_plugin_cb_flags flags,
 101                                             void *udata)
 102 {
 103     plugin_register_dyn_cb__udata(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR],
 104         cb, flags, udata);
 105 }
 106
 107 void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
 108                                                 enum qemu_plugin_op op,
 109                                                 void *ptr, uint64_t imm)
 110 {
 111     plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
 112                               0, op, ptr, imm);
 113 }
 114
 115
 116
 117 void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
 118                                       qemu_plugin_vcpu_mem_cb_t cb,
 119                                       enum qemu_plugin_cb_flags flags,
 120                                       enum qemu_plugin_mem_rw rw,
 121                                       void *udata)
 122 {
 123     plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
 124                                 cb, flags, rw, udata);
 125 }
 126
 127 void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
 128                                           enum qemu_plugin_mem_rw rw,
 129                                           enum qemu_plugin_op op, void *ptr,
 130                                           uint64_t imm)
 131 {
 132     plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
 133         rw, op, ptr, imm);
 134 }
 135
 136 void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
 137                                            qemu_plugin_vcpu_tb_trans_cb_t cb)
 138 {
 139     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb);
 140 }
 141
 142 void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
 143                                           qemu_plugin_vcpu_syscall_cb_t cb)
 144 {
 145     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
 146 }
 147
 148 void
 149 qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
 150                                          qemu_plugin_vcpu_syscall_ret_cb_t cb)
 151 {
 152     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb);
 153 }
 154
 155 /*
 156  * Plugin Queries
 157  *
 158  * These are queries that the plugin can make to gauge information
 159  * from our opaque data types. We do not want to leak internal details
 160  * here just information useful to the plugin.
 161  */
 162
 163 /*
 164  * Translation block information:
 165  *
 166  * A plugin can query the virtual address of the start of the block
 167  * and the number of instructions in it. It can also get access to
 168  * each translated instruction.
 169  */
 170
 171 size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb)
 172 {
 173     return tb->n;
 174 }
 175
 176 uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb)
 177 {
 178     return tb->vaddr;
 179 }
 180
 181 struct qemu_plugin_insn *
 182 qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
 183 {
 184     if (unlikely(idx >= tb->n)) {
 185         return NULL;
 186     }
 187     return g_ptr_array_index(tb->insns, idx);
 188 }
 189
 190 /*
 191  * Instruction information
 192  *
 193  * These queries allow the plugin to retrieve information about each
 194  * instruction being translated.
 195  */
 196
 197 const void *qemu_plugin_insn_data(const struct qemu_plugin_insn *insn)
 198 {
 199     return insn->data->data;
 200 }
 201
 202 size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
 203 {
 204     return insn->data->len;
 205 }
 206
 207 uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
 208 {
 209     return insn->vaddr;
 210 }
 211
 212 void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
 213 {
 214     return insn->haddr;
 215 }
 216
 217 char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
 218 {
 219     CPUState *cpu = current_cpu;
 220     return plugin_disas(cpu, insn->vaddr, insn->data->len);
 221 }
 222
 223 /*
 224  * The memory queries allow the plugin to query information about a
 225  * memory access.
 226  */
 227
 228 unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info)
 229 {
 230     return info & TRACE_MEM_SZ_SHIFT_MASK;
 231 }
 232
 233 bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info)
 234 {
 235     return !!(info & TRACE_MEM_SE);
 236 }
 237
 238 bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info)
 239 {
 240     return !!(info & TRACE_MEM_BE);
 241 }
 242
 243 bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info)
 244 {
 245     return !!(info & TRACE_MEM_ST);
 246 }
 247
 248 /*
 249  * Virtual Memory queries
 250  */
 251
 252 #ifdef CONFIG_SOFTMMU
 253 static __thread struct qemu_plugin_hwaddr hwaddr_info;
 254
 255 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
 256                                                   uint64_t vaddr)
 257 {
 258     CPUState *cpu = current_cpu;
 259     unsigned int mmu_idx = info >> TRACE_MEM_MMU_SHIFT;
 260     hwaddr_info.is_store = info & TRACE_MEM_ST;
 261
 262     if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx,
 263                            info & TRACE_MEM_ST, &hwaddr_info)) {
 264         error_report("invalid use of qemu_plugin_get_hwaddr");
 265         return NULL;
 266     }
 267
 268     return &hwaddr_info;
 269 }
 270 #else
 271 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
 272                                                   uint64_t vaddr)
 273 {
 274     return NULL;
 275 }
 276 #endif
 277
 278 bool qemu_plugin_hwaddr_is_io(struct qemu_plugin_hwaddr *hwaddr)
 279 {
 280 #ifdef CONFIG_SOFTMMU
 281     return hwaddr->is_io;
 282 #else
 283     return false;
 284 #endif
 285 }
 286
 287 uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr)
 288 {
 289 #ifdef CONFIG_SOFTMMU
 290     if (haddr) {
 291         if (!haddr->is_io) {
 292             ram_addr_t ram_addr = qemu_ram_addr_from_host((void *) haddr->v.ram.hostaddr);
 293             if (ram_addr == RAM_ADDR_INVALID) {
 294                 error_report("Bad ram pointer %"PRIx64"", haddr->v.ram.hostaddr);
 295                 abort();
 296             }
 297             return ram_addr;
 298         } else {
 299             return haddr->v.io.offset;
 300         }
 301     }
 302 #endif
 303     return 0;
 304 }
 305
 306 /*
 307  * Queries to the number and potential maximum number of vCPUs there
 308  * will be. This helps the plugin dimension per-vcpu arrays.
 309  */
 310
 311 #ifndef CONFIG_USER_ONLY
 312 static MachineState * get_ms(void)
 313 {
 314     return MACHINE(qdev_get_machine());
 315 }
 316 #endif
 317
 318 int qemu_plugin_n_vcpus(void)
 319 {
 320 #ifdef CONFIG_USER_ONLY
 321     return -1;
 322 #else
 323     return get_ms()->smp.cpus;
 324 #endif
 325 }
 326
 327 int qemu_plugin_n_max_vcpus(void)
 328 {
 329 #ifdef CONFIG_USER_ONLY
 330     return -1;
 331 #else
 332     return get_ms()->smp.max_cpus;
 333 #endif
 334 }
 335
 336 /*
 337  * Plugin output
 338  */
 339 void qemu_plugin_outs(const char *string)
 340 {
 341     qemu_log_mask(CPU_LOG_PLUGIN, "%s", string);
 342 }