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
  50 /* Uninstall and Reset handlers */
  51
  52 void qemu_plugin_uninstall(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
  53 {
  54     plugin_reset_uninstall(id, cb, false);
  55 }
  56
  57 void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
  58 {
  59     plugin_reset_uninstall(id, cb, true);
  60 }
  61
  62 /*
  63  * Plugin Register Functions
  64  *
  65  * This allows the plugin to register callbacks for various events
  66  * during the translation.
  67  */
  68
  69 void qemu_plugin_register_vcpu_init_cb(qemu_plugin_id_t id,
  70                                        qemu_plugin_vcpu_simple_cb_t cb)
  71 {
  72     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_INIT, cb);
  73 }
  74
  75 void qemu_plugin_register_vcpu_exit_cb(qemu_plugin_id_t id,
  76                                        qemu_plugin_vcpu_simple_cb_t cb)
  77 {
  78     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_EXIT, cb);
  79 }
  80
  81 void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
  82                                           qemu_plugin_vcpu_udata_cb_t cb,
  83                                           enum qemu_plugin_cb_flags flags,
  84                                           void *udata)
  85 {
  86     plugin_register_dyn_cb__udata(&tb->cbs[PLUGIN_CB_REGULAR],
  87                                   cb, flags, udata);
  88 }
  89
  90 void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
  91                                               enum qemu_plugin_op op,
  92                                               void *ptr, uint64_t imm)
  93 {
  94     plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
  95 }
  96
  97 void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
  98                                             qemu_plugin_vcpu_udata_cb_t cb,
  99                                             enum qemu_plugin_cb_flags flags,
 100                                             void *udata)
 101 {
 102     plugin_register_dyn_cb__udata(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR],
 103         cb, flags, udata);
 104 }
 105
 106 void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
 107                                                 enum qemu_plugin_op op,
 108                                                 void *ptr, uint64_t imm)
 109 {
 110     plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
 111                               0, op, ptr, imm);
 112 }
 113
 114
 115
 116 void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
 117                                       qemu_plugin_vcpu_mem_cb_t cb,
 118                                       enum qemu_plugin_cb_flags flags,
 119                                       enum qemu_plugin_mem_rw rw,
 120                                       void *udata)
 121 {
 122     plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
 123                                 cb, flags, rw, udata);
 124 }
 125
 126 void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
 127                                           enum qemu_plugin_mem_rw rw,
 128                                           enum qemu_plugin_op op, void *ptr,
 129                                           uint64_t imm)
 130 {
 131     plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
 132         rw, op, ptr, imm);
 133 }
 134
 135 void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
 136                                            qemu_plugin_vcpu_tb_trans_cb_t cb)
 137 {
 138     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb);
 139 }
 140
 141 void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
 142                                           qemu_plugin_vcpu_syscall_cb_t cb)
 143 {
 144     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
 145 }
 146
 147 void
 148 qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
 149                                          qemu_plugin_vcpu_syscall_ret_cb_t cb)
 150 {
 151     plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb);
 152 }
 153
 154 /*
 155  * Plugin Queries
 156  *
 157  * These are queries that the plugin can make to gauge information
 158  * from our opaque data types. We do not want to leak internal details
 159  * here just information useful to the plugin.
 160  */
 161
 162 /*
 163  * Translation block information:
 164  *
 165  * A plugin can query the virtual address of the start of the block
 166  * and the number of instructions in it. It can also get access to
 167  * each translated instruction.
 168  */
 169
 170 size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb)
 171 {
 172     return tb->n;
 173 }
 174
 175 uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb)
 176 {
 177     return tb->vaddr;
 178 }
 179
 180 struct qemu_plugin_insn *
 181 qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
 182 {
 183     if (unlikely(idx >= tb->n)) {
 184         return NULL;
 185     }
 186     return g_ptr_array_index(tb->insns, idx);
 187 }
 188
 189 /*
 190  * Instruction information
 191  *
 192  * These queries allow the plugin to retrieve information about each
 193  * instruction being translated.
 194  */
 195
 196 const void *qemu_plugin_insn_data(const struct qemu_plugin_insn *insn)
 197 {
 198     return insn->data->data;
 199 }
 200
 201 size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
 202 {
 203     return insn->data->len;
 204 }
 205
 206 uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
 207 {
 208     return insn->vaddr;
 209 }
 210
 211 void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
 212 {
 213     return insn->haddr;
 214 }
 215
 216 char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
 217 {
 218     CPUState *cpu = current_cpu;
 219     return plugin_disas(cpu, insn->vaddr, insn->data->len);
 220 }
 221
 222 /*
 223  * The memory queries allow the plugin to query information about a
 224  * memory access.
 225  */
 226
 227 unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info)
 228 {
 229     return info & TRACE_MEM_SZ_SHIFT_MASK;
 230 }
 231
 232 bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info)
 233 {
 234     return !!(info & TRACE_MEM_SE);
 235 }
 236
 237 bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info)
 238 {
 239     return !!(info & TRACE_MEM_BE);
 240 }
 241
 242 bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info)
 243 {
 244     return !!(info & TRACE_MEM_ST);
 245 }
 246
 247 /*
 248  * Virtual Memory queries
 249  */
 250
 251 #ifdef CONFIG_SOFTMMU
 252 static __thread struct qemu_plugin_hwaddr hwaddr_info;
 253
 254 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
 255                                                   uint64_t vaddr)
 256 {
 257     CPUState *cpu = current_cpu;
 258     unsigned int mmu_idx = info >> TRACE_MEM_MMU_SHIFT;
 259     hwaddr_info.is_store = info & TRACE_MEM_ST;
 260
 261     if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx,
 262                            info & TRACE_MEM_ST, &hwaddr_info)) {
 263         error_report("invalid use of qemu_plugin_get_hwaddr");
 264         return NULL;
 265     }
 266
 267     return &hwaddr_info;
 268 }
 269 #else
 270 struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
 271                                                   uint64_t vaddr)
 272 {
 273     return NULL;
 274 }
 275 #endif
 276
 277 bool qemu_plugin_hwaddr_is_io(struct qemu_plugin_hwaddr *hwaddr)
 278 {
 279 #ifdef CONFIG_SOFTMMU
 280     return hwaddr->is_io;
 281 #else
 282     return false;
 283 #endif
 284 }
 285
 286 uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr)
 287 {
 288 #ifdef CONFIG_SOFTMMU
 289     if (haddr) {
 290         if (!haddr->is_io) {
 291             ram_addr_t ram_addr = qemu_ram_addr_from_host((void *) haddr->v.ram.hostaddr);
 292             if (ram_addr == RAM_ADDR_INVALID) {
 293                 error_report("Bad ram pointer %"PRIx64"", haddr->v.ram.hostaddr);
 294                 abort();
 295             }
 296             return ram_addr;
 297         } else {
 298             return haddr->v.io.offset;
 299         }
 300     }
 301 #endif
 302     return 0;
 303 }
 304
 305 /*
 306  * Queries to the number and potential maximum number of vCPUs there
 307  * will be. This helps the plugin dimension per-vcpu arrays.
 308  */
 309
 310 #ifndef CONFIG_USER_ONLY
 311 static MachineState * get_ms(void)
 312 {
 313     return MACHINE(qdev_get_machine());
 314 }
 315 #endif
 316
 317 int qemu_plugin_n_vcpus(void)
 318 {
 319 #ifdef CONFIG_USER_ONLY
 320     return -1;
 321 #else
 322     return get_ms()->smp.cpus;
 323 #endif
 324 }
 325
 326 int qemu_plugin_n_max_vcpus(void)
 327 {
 328 #ifdef CONFIG_USER_ONLY
 329     return -1;
 330 #else
 331     return get_ms()->smp.max_cpus;
 332 #endif
 333 }