This demonstrates how a register can be read from a plugin.
Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
---
docs/devel/tcg-plugins.rst | 10 +++-
contrib/plugins/execlog.c | 120 +++++++++++++++++++++++++++----------
2 files changed, 97 insertions(+), 33 deletions(-)
diff --git a/docs/devel/tcg-plugins.rst b/docs/devel/tcg-plugins.rst
index 81dcd43a61..c9f8b27590 100644
--- a/docs/devel/tcg-plugins.rst
+++ b/docs/devel/tcg-plugins.rst
@@ -497,6 +497,15 @@ arguments if required::
$ qemu-system-arm $(QEMU_ARGS) \
-plugin ./contrib/plugins/libexeclog.so,ifilter=st1w,afilter=0x40001808 -d
plugin
+This plugin can also dump a specified register. The specification of register
+follows `GDB standard target features
<https://sourceware.org/gdb/onlinedocs/gdb/Standard-Target-Features.html>`__.
+
+Specify the name of the feature that contains the register and the name of the
+register with ``rfile`` and ``reg`` options, respectively::
+
+ $ qemu-system-arm $(QEMU_ARGS) \
+ -plugin ./contrib/plugins/libexeclog.so,rfile=org.gnu.gdb.arm.core,reg=sp
-d plugin
+
- contrib/plugins/cache.c
Cache modelling plugin that measures the performance of a given L1 cache
@@ -583,4 +592,3 @@ The following API is generated from the inline
documentation in
include the full kernel-doc annotations.
.. kernel-doc:: include/qemu/qemu-plugin.h
-
diff --git a/contrib/plugins/execlog.c b/contrib/plugins/execlog.c
index 82dc2f584e..f3e714c888 100644
--- a/contrib/plugins/execlog.c
+++ b/contrib/plugins/execlog.c
@@ -15,27 +15,43 @@
#include <qemu-plugin.h>
+typedef struct CPU {
+ /* Store last executed instruction on each vCPU as a GString */
+ GString *last_exec;
+ GByteArray *reg_history[2];
+
+ int reg;
+} CPU;
+
QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
-/* Store last executed instruction on each vCPU as a GString */
-static GPtrArray *last_exec;
+static CPU *cpus;
+static int num_cpus;
static GRWLock expand_array_lock;
static GPtrArray *imatches;
static GArray *amatches;
+static char *rfile_name;
+static char *reg_name;
+
/*
- * Expand last_exec array.
+ * Expand cpu array.
*
* As we could have multiple threads trying to do this we need to
* serialise the expansion under a lock.
*/
-static void expand_last_exec(int cpu_index)
+static void expand_cpu(int cpu_index)
{
g_rw_lock_writer_lock(&expand_array_lock);
- while (cpu_index >= last_exec->len) {
- GString *s = g_string_new(NULL);
- g_ptr_array_add(last_exec, s);
+ if (cpu_index >= num_cpus) {
+ cpus = g_realloc_n(cpus, cpu_index + 1, sizeof(*cpus));
+ while (cpu_index >= num_cpus) {
+ cpus[num_cpus].last_exec = g_string_new(NULL);
+ cpus[num_cpus].reg_history[0] = g_byte_array_new();
+ cpus[num_cpus].reg_history[1] = g_byte_array_new();
+ num_cpus++;
+ }
}
g_rw_lock_writer_unlock(&expand_array_lock);
}
@@ -50,8 +66,8 @@ static void vcpu_mem(unsigned int cpu_index,
qemu_plugin_meminfo_t info,
/* Find vCPU in array */
g_rw_lock_reader_lock(&expand_array_lock);
- g_assert(cpu_index < last_exec->len);
- s = g_ptr_array_index(last_exec, cpu_index);
+ g_assert(cpu_index < num_cpus);
+ s = cpus[cpu_index].last_exec;
g_rw_lock_reader_unlock(&expand_array_lock);
/* Indicate type of memory access */
@@ -77,28 +93,42 @@ static void vcpu_mem(unsigned int cpu_index,
qemu_plugin_meminfo_t info,
*/
static void vcpu_insn_exec(unsigned int cpu_index, void *udata)
{
- GString *s;
+ int n;
+ int i;
- /* Find or create vCPU in array */
g_rw_lock_reader_lock(&expand_array_lock);
- if (cpu_index >= last_exec->len) {
- g_rw_lock_reader_unlock(&expand_array_lock);
- expand_last_exec(cpu_index);
- g_rw_lock_reader_lock(&expand_array_lock);
- }
- s = g_ptr_array_index(last_exec, cpu_index);
- g_rw_lock_reader_unlock(&expand_array_lock);
/* Print previous instruction in cache */
- if (s->len) {
- qemu_plugin_outs(s->str);
+ if (cpus[cpu_index].last_exec->len) {
+ if (cpus[cpu_index].reg >= 0) {
+ GByteArray *current = cpus[cpu_index].reg_history[0];
+ GByteArray *last = cpus[cpu_index].reg_history[1];
+
+ g_byte_array_set_size(current, 0);
+ n = qemu_plugin_read_register(current, cpus[cpu_index].reg);
+
+ if (n != last->len || memcmp(current->data, last->data, n)) {
+ g_string_append(cpus[cpu_index].last_exec, ", reg,");
+ for (i = 0; i < n; i++) {
+ g_string_append_printf(cpus[cpu_index].last_exec, " %02x",
+ current->data[i]);
+ }
+ }
+
+ cpus[cpu_index].reg_history[0] = last;
+ cpus[cpu_index].reg_history[1] = current;
+ }
+
+ qemu_plugin_outs(cpus[cpu_index].last_exec->str);
qemu_plugin_outs("\n");
}
/* Store new instruction in cache */
/* vcpu_mem will add memory access information to last_exec */
- g_string_printf(s, "%u, ", cpu_index);
- g_string_append(s, (char *)udata);
+ g_string_printf(cpus[cpu_index].last_exec, "%u, ", cpu_index);
+ g_string_append(cpus[cpu_index].last_exec, (char *)udata);
+
+ g_rw_lock_reader_unlock(&expand_array_lock);
}
/**
@@ -167,8 +197,10 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct
qemu_plugin_tb *tb)
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);
+ qemu_plugin_register_vcpu_insn_exec_cb(
+ insn, vcpu_insn_exec,
+ rfile_name ? QEMU_PLUGIN_CB_R_REGS : QEMU_PLUGIN_CB_NO_REGS,
+ output);
/* reset skip */
skip = (imatches || amatches);
@@ -177,17 +209,33 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct
qemu_plugin_tb *tb)
}
}
+static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index)
+{
+ int reg = -1;
+
+ expand_cpu(vcpu_index);
+
+ if (rfile_name) {
+ int rfile = qemu_plugin_find_register_file(vcpu_index, rfile_name);
+ if (rfile >= 0) {
+ reg = qemu_plugin_find_register(vcpu_index, rfile, reg_name);
+ }
+ }
+
+ g_rw_lock_writer_lock(&expand_array_lock);
+ cpus[vcpu_index].reg = reg;
+ g_rw_lock_writer_unlock(&expand_array_lock);
+}
+
/**
* On plugin exit, print last instruction in cache
*/
static void plugin_exit(qemu_plugin_id_t id, void *p)
{
guint i;
- GString *s;
- for (i = 0; i < last_exec->len; i++) {
- s = g_ptr_array_index(last_exec, i);
- if (s->str) {
- qemu_plugin_outs(s->str);
+ for (i = 0; i < num_cpus; i++) {
+ if (cpus[i].last_exec->str) {
+ qemu_plugin_outs(cpus[i].last_exec->str);
qemu_plugin_outs("\n");
}
}
@@ -224,9 +272,7 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t
id,
* we don't know the size before emulation.
*/
if (info->system_emulation) {
- last_exec = g_ptr_array_sized_new(info->system.max_vcpus);
- } else {
- last_exec = g_ptr_array_new();
+ cpus = g_new(CPU, info->system.max_vcpus);
}
for (int i = 0; i < argc; i++) {
@@ -236,13 +282,23 @@ QEMU_PLUGIN_EXPORT int
qemu_plugin_install(qemu_plugin_id_t id,
parse_insn_match(tokens[1]);
} else if (g_strcmp0(tokens[0], "afilter") == 0) {
parse_vaddr_match(tokens[1]);
+ } else if (g_strcmp0(tokens[0], "rfile") == 0) {
+ rfile_name = g_strdup(tokens[1]);
+ } else if (g_strcmp0(tokens[0], "reg") == 0) {
+ reg_name = g_strdup(tokens[1]);
} else {
fprintf(stderr, "option parsing failed: %s\n", opt);
return -1;
}
}
+ if ((!rfile_name) != (!reg_name)) {
+ fputs("file and reg need to be set at the same time\n", stderr);
+ return -1;
+ }
+
/* Register translation block and exit callbacks */
+ qemu_plugin_register_vcpu_init_cb(id, vcpu_init);
qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
--
2.42.0
