Log instruction execution and memory access to a file.
This plugin can be used for reverse engineering or for side-channel analysis
using QEMU.
Signed-off-by: Alexandre Iooss <erdn...@crans.org>
---
MAINTAINERS | 1 +
contrib/plugins/Makefile | 1 +
contrib/plugins/execlog.c | 123 ++++++++++++++++++++++++++++++++++++++
3 files changed, 125 insertions(+)
create mode 100644 contrib/plugins/execlog.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 7d9cd29042..65942d5802 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2974,6 +2974,7 @@ F: include/tcg/
TCG Plugins
M: Alex Bennée <alex.ben...@linaro.org>
+R: Alexandre Iooss <erdn...@crans.org>
S: Maintained
F: docs/devel/tcg-plugins.rst
F: plugins/
diff --git a/contrib/plugins/Makefile b/contrib/plugins/Makefile
index b9d7935e5e..51093acd17 100644
--- a/contrib/plugins/Makefile
+++ b/contrib/plugins/Makefile
@@ -13,6 +13,7 @@ include $(BUILD_DIR)/config-host.mak
VPATH += $(SRC_PATH)/contrib/plugins
NAMES :=
+NAMES += execlog
NAMES += hotblocks
NAMES += hotpages
NAMES += howvec
diff --git a/contrib/plugins/execlog.c b/contrib/plugins/execlog.c
new file mode 100644
index 0000000000..995c4477f9
--- /dev/null
+++ b/contrib/plugins/execlog.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2021, Alexandre Iooss <erdn...@crans.org>
+ *
+ * Log instruction execution with memory access.
+ *
+ * License: GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include <glib.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <qemu-plugin.h>
+
+QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
+
+/* Store last executed instruction on each vCPU */
+GString **last_exec;
+
+/**
+ * Add memory read or write information to current instruction log
+ */
+static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t info,
+ uint64_t vaddr, void *udata)
+{
+ if (qemu_plugin_mem_is_store(info)) {
+ g_string_append(last_exec[cpu_index], ", store");
+ } else {
+ g_string_append(last_exec[cpu_index], ", load");
+ }
+
+ /* If full system emulation log physical address and device name */
+ struct qemu_plugin_hwaddr *hwaddr = qemu_plugin_get_hwaddr(info, vaddr);
+ if (hwaddr) {
+ uint64_t addr = qemu_plugin_hwaddr_phys_addr(hwaddr);
+ const char *name = qemu_plugin_hwaddr_device_name(hwaddr);
+ g_string_append_printf(last_exec[cpu_index], ", 0x%08"PRIx64", %s",
+ addr, name);
+ } else {
+ g_string_append_printf(last_exec[cpu_index], ", 0x%08"PRIx64, vaddr);
+ }
+}
+
+/**
+ * Log instruction execution
+ */
+static void vcpu_insn_exec(unsigned int cpu_index, void *udata)
+{
+ /* Print previous instruction in cache */
+ if (last_exec[cpu_index]->str) {
+ qemu_plugin_outs(last_exec[cpu_index]->str);
+ qemu_plugin_outs("\n");
+ }
+
+ /* Store new instruction in cache */
+ /* vcpu_mem will add memory access information to last_exec */
+ g_string_printf(last_exec[cpu_index], "%u, ", cpu_index);
+ g_string_append(last_exec[cpu_index], (char *)udata);
+}
+
+/**
+ * On translation block new translation
+ *
+ * QEMU convert code by translation block (TB). By hooking here we can then
hook
+ * a callback on each instruction and memory access.
+ */
+static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
+{
+ struct qemu_plugin_insn *insn;
+ uint64_t insn_vaddr;
+ uint32_t insn_opcode;
+ char *insn_disas;
+
+ size_t n = qemu_plugin_tb_n_insns(tb);
+ for (size_t i = 0; i < n; i++) {
+ /*
+ * `insn` is shared between translations in QEMU, copy needed data
here.
+ * `output` is never freed as it might be used multiple times during
+ * the emulation lifetime.
+ * We only consider the first 32 bits of the instruction, this may be
+ * a limitation for CISC architectures.
+ */
+ insn = qemu_plugin_tb_get_insn(tb, i);
+ insn_vaddr = qemu_plugin_insn_vaddr(insn);
+ insn_opcode = *((uint32_t *)qemu_plugin_insn_data(insn));
+ insn_disas = qemu_plugin_insn_disas(insn);
+ char *output = g_strdup_printf("0x%"PRIx64", 0x%"PRIx32", \"%s\"",
+ insn_vaddr, insn_opcode, insn_disas);
+
+ /* Register callback on memory read or write */
+ qemu_plugin_register_vcpu_mem_cb(insn, vcpu_mem,
+ QEMU_PLUGIN_CB_NO_REGS,
+ QEMU_PLUGIN_MEM_RW, NULL);
+
+ /* Register callback on instruction */
+ qemu_plugin_register_vcpu_insn_exec_cb(insn, vcpu_insn_exec,
+ QEMU_PLUGIN_CB_NO_REGS, output);
+ }
+}
+
+/**
+ * Install the plugin
+ */
+QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
+ const qemu_info_t *info, int argc,
+ char **argv)
+{
+ int i;
+
+ /* Initialize instruction cache for each vCPU */
+ last_exec = calloc(info->system.max_vcpus, sizeof(GString *));
+ for (i = 0; i < info->system.max_vcpus; i++) {
+ last_exec[i] = g_string_new(NULL);
+ }
+
+ /* Register translation block callback */
+ qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
+
+ return 0;
+}
--
2.25.1
