Alexandre Iooss | 3d7caf1 | 2021-07-09 15:29:59 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2021, Alexandre Iooss <erdnaxe@crans.org> |
| 3 | * |
| 4 | * Log instruction execution with memory access. |
| 5 | * |
| 6 | * License: GNU GPL, version 2 or later. |
| 7 | * See the COPYING file in the top-level directory. |
| 8 | */ |
| 9 | #include <glib.h> |
| 10 | #include <inttypes.h> |
| 11 | #include <stdio.h> |
| 12 | #include <stdlib.h> |
| 13 | #include <string.h> |
| 14 | #include <unistd.h> |
| 15 | |
| 16 | #include <qemu-plugin.h> |
| 17 | |
| 18 | QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; |
| 19 | |
| 20 | /* Store last executed instruction on each vCPU as a GString */ |
| 21 | GArray *last_exec; |
| 22 | |
| 23 | /** |
| 24 | * Add memory read or write information to current instruction log |
| 25 | */ |
| 26 | static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t info, |
| 27 | uint64_t vaddr, void *udata) |
| 28 | { |
| 29 | GString *s; |
| 30 | |
| 31 | /* Find vCPU in array */ |
| 32 | g_assert(cpu_index < last_exec->len); |
| 33 | s = g_array_index(last_exec, GString *, cpu_index); |
| 34 | |
| 35 | /* Indicate type of memory access */ |
| 36 | if (qemu_plugin_mem_is_store(info)) { |
| 37 | g_string_append(s, ", store"); |
| 38 | } else { |
| 39 | g_string_append(s, ", load"); |
| 40 | } |
| 41 | |
| 42 | /* If full system emulation log physical address and device name */ |
| 43 | struct qemu_plugin_hwaddr *hwaddr = qemu_plugin_get_hwaddr(info, vaddr); |
| 44 | if (hwaddr) { |
| 45 | uint64_t addr = qemu_plugin_hwaddr_phys_addr(hwaddr); |
| 46 | const char *name = qemu_plugin_hwaddr_device_name(hwaddr); |
| 47 | g_string_append_printf(s, ", 0x%08"PRIx64", %s", addr, name); |
| 48 | } else { |
| 49 | g_string_append_printf(s, ", 0x%08"PRIx64, vaddr); |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * Log instruction execution |
| 55 | */ |
| 56 | static void vcpu_insn_exec(unsigned int cpu_index, void *udata) |
| 57 | { |
| 58 | GString *s; |
| 59 | |
| 60 | /* Find or create vCPU in array */ |
| 61 | while (cpu_index >= last_exec->len) { |
| 62 | s = g_string_new(NULL); |
| 63 | g_array_append_val(last_exec, s); |
| 64 | } |
| 65 | s = g_array_index(last_exec, GString *, cpu_index); |
| 66 | |
| 67 | /* Print previous instruction in cache */ |
| 68 | if (s->len) { |
| 69 | qemu_plugin_outs(s->str); |
| 70 | qemu_plugin_outs("s\n"); |
| 71 | } |
| 72 | |
| 73 | /* Store new instruction in cache */ |
| 74 | /* vcpu_mem will add memory access information to last_exec */ |
| 75 | g_string_printf(s, "%u, ", cpu_index); |
| 76 | g_string_append(s, (char *)udata); |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * On translation block new translation |
| 81 | * |
| 82 | * QEMU convert code by translation block (TB). By hooking here we can then hook |
| 83 | * a callback on each instruction and memory access. |
| 84 | */ |
| 85 | static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb) |
| 86 | { |
| 87 | struct qemu_plugin_insn *insn; |
| 88 | uint64_t insn_vaddr; |
| 89 | uint32_t insn_opcode; |
| 90 | char *insn_disas; |
| 91 | |
| 92 | size_t n = qemu_plugin_tb_n_insns(tb); |
| 93 | for (size_t i = 0; i < n; i++) { |
| 94 | /* |
| 95 | * `insn` is shared between translations in QEMU, copy needed data here. |
| 96 | * `output` is never freed as it might be used multiple times during |
| 97 | * the emulation lifetime. |
| 98 | * We only consider the first 32 bits of the instruction, this may be |
| 99 | * a limitation for CISC architectures. |
| 100 | */ |
| 101 | insn = qemu_plugin_tb_get_insn(tb, i); |
| 102 | insn_vaddr = qemu_plugin_insn_vaddr(insn); |
| 103 | insn_opcode = *((uint32_t *)qemu_plugin_insn_data(insn)); |
| 104 | insn_disas = qemu_plugin_insn_disas(insn); |
| 105 | char *output = g_strdup_printf("0x%"PRIx64", 0x%"PRIx32", \"%s\"", |
| 106 | insn_vaddr, insn_opcode, insn_disas); |
| 107 | |
| 108 | /* Register callback on memory read or write */ |
| 109 | qemu_plugin_register_vcpu_mem_cb(insn, vcpu_mem, |
| 110 | QEMU_PLUGIN_CB_NO_REGS, |
| 111 | QEMU_PLUGIN_MEM_RW, NULL); |
| 112 | |
| 113 | /* Register callback on instruction */ |
| 114 | qemu_plugin_register_vcpu_insn_exec_cb(insn, vcpu_insn_exec, |
| 115 | QEMU_PLUGIN_CB_NO_REGS, output); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * On plugin exit, print last instruction in cache |
| 121 | */ |
| 122 | static void plugin_exit(qemu_plugin_id_t id, void *p) |
| 123 | { |
| 124 | guint i; |
| 125 | GString *s; |
| 126 | for (i = 0; i < last_exec->len; i++) { |
| 127 | s = g_array_index(last_exec, GString *, i); |
| 128 | if (s->str) { |
| 129 | qemu_plugin_outs(s->str); |
| 130 | qemu_plugin_outs("\n"); |
| 131 | } |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Install the plugin |
| 137 | */ |
| 138 | QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id, |
| 139 | const qemu_info_t *info, int argc, |
| 140 | char **argv) |
| 141 | { |
| 142 | /* |
| 143 | * Initialize dynamic array to cache vCPU instruction. In user mode |
| 144 | * we don't know the size before emulation. |
| 145 | */ |
| 146 | last_exec = g_array_new(FALSE, FALSE, sizeof(GString *)); |
| 147 | |
| 148 | /* Register translation block and exit callbacks */ |
| 149 | qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans); |
| 150 | qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); |
| 151 | |
| 152 | return 0; |
| 153 | } |