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plugin: add core code

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Signed-off-by: Emilio G. Cota <cota@braap.org>
[AJB: moved directory and merged various fixes]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Emilio G. Cota 2017-08-30 18:39:53 -04:00 committed by Alex Bennée
parent 975c455346
commit 54cb65d858
9 changed files with 1241 additions and 1 deletions
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9
Makefile
View file

@ -853,7 +853,11 @@ endif
ICON_SIZES=16x16 24x24 32x32 48x48 64x64 128x128 256x256 512x512
install: all $(if $(BUILD_DOCS),install-doc) install-datadir install-localstatedir \
install-includedir:
$(INSTALL_DIR) "$(DESTDIR)$(includedir)"
install: all $(if $(BUILD_DOCS),install-doc) \
install-datadir install-localstatedir install-includedir \
$(if $(INSTALL_BLOBS),$(edk2-decompressed)) \
recurse-install
ifneq ($(TOOLS),)
@ -915,6 +919,9 @@ endif
"$(DESTDIR)$(qemu_desktopdir)/qemu.desktop"
ifdef CONFIG_GTK
$(MAKE) -C po $@
endif
ifeq ($(CONFIG_PLUGIN),y)
$(INSTALL_DATA) $(SRC_PATH)/include/qemu/qemu-plugin.h "$(DESTDIR)$(includedir)/qemu-plugin.h"
endif
$(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)/keymaps"
set -e; for x in $(KEYMAPS); do \

2
Makefile.target
View file

@ -119,6 +119,8 @@ obj-y += disas.o
obj-$(call notempty,$(TARGET_XML_FILES)) += gdbstub-xml.o
LIBS := $(libs_cpu) $(LIBS)
obj-$(CONFIG_PLUGIN) += plugins/
#########################################################
# Linux user emulator target

3
configure vendored
View file

@ -3616,6 +3616,9 @@ glib_modules=gthread-2.0
if test "$modules" = yes; then
glib_modules="$glib_modules gmodule-export-2.0"
fi
if test "$plugins" = yes; then
glib_modules="$glib_modules gmodule-2.0"
fi
# This workaround is required due to a bug in pkg-config file for glib as it
# doesn't define GLIB_STATIC_COMPILATION for pkg-config --static

6
include/hw/core/cpu.h
View file

@ -29,6 +29,7 @@
#include "qemu/rcu_queue.h"
#include "qemu/queue.h"
#include "qemu/thread.h"
#include "qemu/plugin.h"
typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,
void *opaque);
@ -344,6 +345,7 @@ struct qemu_work_item;
* @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes
* to @trace_dstate).
* @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask).
* @plugin_mask: Plugin event bitmap. Modified only via async work.
* @ignore_memory_transaction_failures: Cached copy of the MachineState
* flag of the same name: allows the board to suppress calling of the
* CPU do_transaction_failed hook function.
@ -428,6 +430,10 @@ struct CPUState {
DECLARE_BITMAP(trace_dstate_delayed, CPU_TRACE_DSTATE_MAX_EVENTS);
DECLARE_BITMAP(trace_dstate, CPU_TRACE_DSTATE_MAX_EVENTS);
DECLARE_BITMAP(plugin_mask, QEMU_PLUGIN_EV_MAX);
GArray *plugin_mem_cbs;
/* TODO Move common fields from CPUArchState here. */
int cpu_index;
int cluster_index;

255
include/qemu/plugin.h Normal file
View file

@ -0,0 +1,255 @@
/*
* Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
*
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef QEMU_PLUGIN_H
#define QEMU_PLUGIN_H
#include "qemu/config-file.h"
#include "qemu/qemu-plugin.h"
#include "qemu/error-report.h"
#include "qemu/queue.h"
#include "qemu/option.h"
/*
* Option parsing/processing.
* Note that we can load an arbitrary number of plugins.
*/
struct qemu_plugin_desc;
typedef QTAILQ_HEAD(, qemu_plugin_desc) QemuPluginList;
#ifdef CONFIG_PLUGIN
extern QemuOptsList qemu_plugin_opts;
static inline void qemu_plugin_add_opts(void)
{
qemu_add_opts(&qemu_plugin_opts);
}
void qemu_plugin_opt_parse(const char *optarg, QemuPluginList *head);
int qemu_plugin_load_list(QemuPluginList *head);
#else /* !CONFIG_PLUGIN */
static inline void qemu_plugin_add_opts(void)
{ }
static inline void qemu_plugin_opt_parse(const char *optarg,
QemuPluginList *head)
{
error_report("plugin interface not enabled in this build");
exit(1);
}
static inline int qemu_plugin_load_list(QemuPluginList *head)
{
return 0;
}
#endif /* !CONFIG_PLUGIN */
/*
* Events that plugins can subscribe to.
*/
enum qemu_plugin_event {
QEMU_PLUGIN_EV_VCPU_INIT,
QEMU_PLUGIN_EV_VCPU_EXIT,
QEMU_PLUGIN_EV_VCPU_TB_TRANS,
QEMU_PLUGIN_EV_VCPU_IDLE,
QEMU_PLUGIN_EV_VCPU_RESUME,
QEMU_PLUGIN_EV_VCPU_SYSCALL,
QEMU_PLUGIN_EV_VCPU_SYSCALL_RET,
QEMU_PLUGIN_EV_FLUSH,
QEMU_PLUGIN_EV_ATEXIT,
QEMU_PLUGIN_EV_MAX, /* total number of plugin events we support */
};
union qemu_plugin_cb_sig {
qemu_plugin_simple_cb_t simple;
qemu_plugin_udata_cb_t udata;
qemu_plugin_vcpu_simple_cb_t vcpu_simple;
qemu_plugin_vcpu_udata_cb_t vcpu_udata;
qemu_plugin_vcpu_tb_trans_cb_t vcpu_tb_trans;
qemu_plugin_vcpu_mem_cb_t vcpu_mem;
qemu_plugin_vcpu_syscall_cb_t vcpu_syscall;
qemu_plugin_vcpu_syscall_ret_cb_t vcpu_syscall_ret;
void *generic;
};
enum plugin_dyn_cb_type {
PLUGIN_CB_INSN,
PLUGIN_CB_MEM,
PLUGIN_N_CB_TYPES,
};
enum plugin_dyn_cb_subtype {
PLUGIN_CB_REGULAR,
PLUGIN_CB_INLINE,
PLUGIN_N_CB_SUBTYPES,
};
/*
* A dynamic callback has an insertion point that is determined at run-time.
* Usually the insertion point is somewhere in the code cache; think for
* instance of a callback to be called upon the execution of a particular TB.
*/
struct qemu_plugin_dyn_cb {
union qemu_plugin_cb_sig f;
void *userp;
unsigned tcg_flags;
enum plugin_dyn_cb_subtype type;
/* @rw applies to mem callbacks only (both regular and inline) */
enum qemu_plugin_mem_rw rw;
/* fields specific to each dyn_cb type go here */
union {
struct {
enum qemu_plugin_op op;
uint64_t imm;
} inline_insn;
};
};
struct qemu_plugin_insn {
GByteArray *data;
uint64_t vaddr;
void *haddr;
GArray *cbs[PLUGIN_N_CB_TYPES][PLUGIN_N_CB_SUBTYPES];
bool calls_helpers;
bool mem_helper;
};
/*
* qemu_plugin_insn allocate and cleanup functions. We don't expect to
* cleanup many of these structures. They are reused for each fresh
* translation.
*/
static inline void qemu_plugin_insn_cleanup_fn(gpointer data)
{
struct qemu_plugin_insn *insn = (struct qemu_plugin_insn *) data;
g_byte_array_free(insn->data, true);
}
static inline struct qemu_plugin_insn *qemu_plugin_insn_alloc(void)
{
int i, j;
struct qemu_plugin_insn *insn = g_new0(struct qemu_plugin_insn, 1);
insn->data = g_byte_array_sized_new(4);
for (i = 0; i < PLUGIN_N_CB_TYPES; i++) {
for (j = 0; j < PLUGIN_N_CB_SUBTYPES; j++) {
insn->cbs[i][j] = g_array_new(false, false,
sizeof(struct qemu_plugin_dyn_cb));
}
}
return insn;
}
struct qemu_plugin_tb {
GPtrArray *insns;
size_t n;
uint64_t vaddr;
uint64_t vaddr2;
void *haddr1;
void *haddr2;
GArray *cbs[PLUGIN_N_CB_SUBTYPES];
};
/**
* qemu_plugin_tb_insn_get(): get next plugin record for translation.
*
*/
static inline
struct qemu_plugin_insn *qemu_plugin_tb_insn_get(struct qemu_plugin_tb *tb)
{
struct qemu_plugin_insn *insn;
int i, j;
if (unlikely(tb->n == tb->insns->len)) {
struct qemu_plugin_insn *new_insn = qemu_plugin_insn_alloc();
g_ptr_array_add(tb->insns, new_insn);
}
insn = g_ptr_array_index(tb->insns, tb->n++);
g_byte_array_set_size(insn->data, 0);
insn->calls_helpers = false;
insn->mem_helper = false;
for (i = 0; i < PLUGIN_N_CB_TYPES; i++) {
for (j = 0; j < PLUGIN_N_CB_SUBTYPES; j++) {
g_array_set_size(insn->cbs[i][j], 0);
}
}
return insn;
}
#ifdef CONFIG_PLUGIN
void qemu_plugin_vcpu_init_hook(CPUState *cpu);
void qemu_plugin_vcpu_exit_hook(CPUState *cpu);
void qemu_plugin_tb_trans_cb(CPUState *cpu, struct qemu_plugin_tb *tb);
void qemu_plugin_vcpu_idle_cb(CPUState *cpu);
void qemu_plugin_vcpu_resume_cb(CPUState *cpu);
void
qemu_plugin_vcpu_syscall(CPUState *cpu, int64_t num, uint64_t a1,
uint64_t a2, uint64_t a3, uint64_t a4, uint64_t a5,
uint64_t a6, uint64_t a7, uint64_t a8);
void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret);
void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr, uint32_t meminfo);
void qemu_plugin_flush_cb(void);
void qemu_plugin_atexit_cb(void);
void qemu_plugin_add_dyn_cb_arr(GArray *arr);
void qemu_plugin_disable_mem_helpers(CPUState *cpu);
#else /* !CONFIG_PLUGIN */
static inline void qemu_plugin_vcpu_init_hook(CPUState *cpu)
{ }
static inline void qemu_plugin_vcpu_exit_hook(CPUState *cpu)
{ }
static inline void qemu_plugin_tb_trans_cb(CPUState *cpu,
struct qemu_plugin_tb *tb)
{ }
static inline void qemu_plugin_vcpu_idle_cb(CPUState *cpu)
{ }
static inline void qemu_plugin_vcpu_resume_cb(CPUState *cpu)
{ }
static inline void
qemu_plugin_vcpu_syscall(CPUState *cpu, int64_t num, uint64_t a1, uint64_t a2,
uint64_t a3, uint64_t a4, uint64_t a5, uint64_t a6,
uint64_t a7, uint64_t a8)
{ }
static inline
void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)
{ }
static inline void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr,
uint32_t meminfo)
{ }
static inline void qemu_plugin_flush_cb(void)
{ }
static inline void qemu_plugin_atexit_cb(void)
{ }
static inline
void qemu_plugin_add_dyn_cb_arr(GArray *arr)
{ }
static inline void qemu_plugin_disable_mem_helpers(CPUState *cpu)
{ }
#endif /* !CONFIG_PLUGIN */
#endif /* QEMU_PLUGIN_H */

6
plugins/Makefile.objs Normal file
View file

@ -0,0 +1,6 @@
#
# Plugin Support
#
obj-y += loader.o
obj-y += core.o

502
plugins/core.c Normal file
View file

@ -0,0 +1,502 @@
/*
* QEMU Plugin Core code
*
* This is the core code that deals with injecting instrumentation into the code
*
* Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
* Copyright (C) 2019, Linaro
*
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
#include "qapi/error.h"
#include "qemu/option.h"
#include "qemu/rcu_queue.h"
#include "qemu/xxhash.h"
#include "qemu/rcu.h"
#include "hw/core/cpu.h"
#include "exec/cpu-common.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "exec/helper-proto.h"
#include "sysemu/sysemu.h"
#include "tcg/tcg.h"
#include "tcg/tcg-op.h"
#include "trace/mem-internal.h" /* mem_info macros */
#include "plugin.h"
struct qemu_plugin_cb {
struct qemu_plugin_ctx *ctx;
union qemu_plugin_cb_sig f;
void *udata;
QLIST_ENTRY(qemu_plugin_cb) entry;
};
struct qemu_plugin_state plugin;
struct qemu_plugin_ctx *plugin_id_to_ctx_locked(qemu_plugin_id_t id)
{
struct qemu_plugin_ctx *ctx;
qemu_plugin_id_t *id_p;
id_p = g_hash_table_lookup(plugin.id_ht, &id);
ctx = container_of(id_p, struct qemu_plugin_ctx, id);
if (ctx == NULL) {
error_report("plugin: invalid plugin id %" PRIu64, id);
abort();
}
return ctx;
}
static void plugin_cpu_update__async(CPUState *cpu, run_on_cpu_data data)
{
bitmap_copy(cpu->plugin_mask, &data.host_ulong, QEMU_PLUGIN_EV_MAX);
cpu_tb_jmp_cache_clear(cpu);
}
static void plugin_cpu_update__locked(gpointer k, gpointer v, gpointer udata)
{
CPUState *cpu = container_of(k, CPUState, cpu_index);
run_on_cpu_data mask = RUN_ON_CPU_HOST_ULONG(*plugin.mask);
if (cpu->created) {
async_run_on_cpu(cpu, plugin_cpu_update__async, mask);
} else {
plugin_cpu_update__async(cpu, mask);
}
}
void plugin_unregister_cb__locked(struct qemu_plugin_ctx *ctx,
enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb = ctx->callbacks[ev];
if (cb == NULL) {
return;
}
QLIST_REMOVE_RCU(cb, entry);
g_free(cb);
ctx->callbacks[ev] = NULL;
if (QLIST_EMPTY_RCU(&plugin.cb_lists[ev])) {
clear_bit(ev, plugin.mask);
g_hash_table_foreach(plugin.cpu_ht, plugin_cpu_update__locked, NULL);
}
}
static void plugin_vcpu_cb__simple(CPUState *cpu, enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb, *next;
switch (ev) {
case QEMU_PLUGIN_EV_VCPU_INIT:
case QEMU_PLUGIN_EV_VCPU_EXIT:
case QEMU_PLUGIN_EV_VCPU_IDLE:
case QEMU_PLUGIN_EV_VCPU_RESUME:
/* iterate safely; plugins might uninstall themselves at any time */
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_simple_cb_t func = cb->f.vcpu_simple;
func(cb->ctx->id, cpu->cpu_index);
}
break;
default:
g_assert_not_reached();
}
}
static void plugin_cb__simple(enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb, *next;
switch (ev) {
case QEMU_PLUGIN_EV_FLUSH:
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_simple_cb_t func = cb->f.simple;
func(cb->ctx->id);
}
break;
default:
g_assert_not_reached();
}
}
static void plugin_cb__udata(enum qemu_plugin_event ev)
{
struct qemu_plugin_cb *cb, *next;
switch (ev) {
case QEMU_PLUGIN_EV_ATEXIT:
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_udata_cb_t func = cb->f.udata;
func(cb->ctx->id, cb->udata);
}
break;
default:
g_assert_not_reached();
}
}
static void
do_plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func, void *udata)
{
struct qemu_plugin_ctx *ctx;
qemu_rec_mutex_lock(&plugin.lock);
ctx = plugin_id_to_ctx_locked(id);
/* if the plugin is on its way out, ignore this request */
if (unlikely(ctx->uninstalling)) {
goto out_unlock;
}
if (func) {
struct qemu_plugin_cb *cb = ctx->callbacks[ev];
if (cb) {
cb->f.generic = func;
cb->udata = udata;
} else {
cb = g_new(struct qemu_plugin_cb, 1);
cb->ctx = ctx;
cb->f.generic = func;
cb->udata = udata;
ctx->callbacks[ev] = cb;
QLIST_INSERT_HEAD_RCU(&plugin.cb_lists[ev], cb, entry);
if (!test_bit(ev, plugin.mask)) {
set_bit(ev, plugin.mask);
g_hash_table_foreach(plugin.cpu_ht, plugin_cpu_update__locked,
NULL);
}
}
} else {
plugin_unregister_cb__locked(ctx, ev);
}
out_unlock:
qemu_rec_mutex_unlock(&plugin.lock);
}
void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func)
{
do_plugin_register_cb(id, ev, func, NULL);
}
void
plugin_register_cb_udata(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func, void *udata)
{
do_plugin_register_cb(id, ev, func, udata);
}
void qemu_plugin_vcpu_init_hook(CPUState *cpu)
{
bool success;
qemu_rec_mutex_lock(&plugin.lock);
plugin_cpu_update__locked(&cpu->cpu_index, NULL, NULL);
success = g_hash_table_insert(plugin.cpu_ht, &cpu->cpu_index,
&cpu->cpu_index);
g_assert(success);
qemu_rec_mutex_unlock(&plugin.lock);
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_INIT);
}
void qemu_plugin_vcpu_exit_hook(CPUState *cpu)
{
bool success;
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_EXIT);
qemu_rec_mutex_lock(&plugin.lock);
success = g_hash_table_remove(plugin.cpu_ht, &cpu->cpu_index);
g_assert(success);
qemu_rec_mutex_unlock(&plugin.lock);
}
struct plugin_for_each_args {
struct qemu_plugin_ctx *ctx;
qemu_plugin_vcpu_simple_cb_t cb;
};
static void plugin_vcpu_for_each(gpointer k, gpointer v, gpointer udata)
{
struct plugin_for_each_args *args = udata;
int cpu_index = *(int *)k;
args->cb(args->ctx->id, cpu_index);
}
void qemu_plugin_vcpu_for_each(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
struct plugin_for_each_args args;
if (cb == NULL) {
return;
}
qemu_rec_mutex_lock(&plugin.lock);
args.ctx = plugin_id_to_ctx_locked(id);
args.cb = cb;
g_hash_table_foreach(plugin.cpu_ht, plugin_vcpu_for_each, &args);
qemu_rec_mutex_unlock(&plugin.lock);
}
/* Allocate and return a callback record */
static struct qemu_plugin_dyn_cb *plugin_get_dyn_cb(GArray **arr)
{
GArray *cbs = *arr;
if (!cbs) {
cbs = g_array_sized_new(false, false,
sizeof(struct qemu_plugin_dyn_cb), 1);
*arr = cbs;
}
g_array_set_size(cbs, cbs->len + 1);
return &g_array_index(cbs, struct qemu_plugin_dyn_cb, cbs->len - 1);
}
void plugin_register_inline_op(GArray **arr,
enum qemu_plugin_mem_rw rw,
enum qemu_plugin_op op, void *ptr,
uint64_t imm)
{
struct qemu_plugin_dyn_cb *dyn_cb;
dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = ptr;
dyn_cb->type = PLUGIN_CB_INLINE;
dyn_cb->rw = rw;
dyn_cb->inline_insn.op = op;
dyn_cb->inline_insn.imm = imm;
}
static inline uint32_t cb_to_tcg_flags(enum qemu_plugin_cb_flags flags)
{
uint32_t ret;
switch (flags) {
case QEMU_PLUGIN_CB_RW_REGS:
ret = 0;
case QEMU_PLUGIN_CB_R_REGS:
ret = TCG_CALL_NO_WG;
break;
case QEMU_PLUGIN_CB_NO_REGS:
default:
ret = TCG_CALL_NO_RWG;
}
return ret;
}
inline void
plugin_register_dyn_cb__udata(GArray **arr,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags, void *udata)
{
struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = udata;
dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
dyn_cb->f.vcpu_udata = cb;
dyn_cb->type = PLUGIN_CB_REGULAR;
}
void plugin_register_vcpu_mem_cb(GArray **arr,
void *cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_mem_rw rw,
void *udata)
{
struct qemu_plugin_dyn_cb *dyn_cb;
dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = udata;
dyn_cb->tcg_flags = cb_to_tcg_flags(flags);
dyn_cb->type = PLUGIN_CB_REGULAR;
dyn_cb->rw = rw;
dyn_cb->f.generic = cb;
}
void qemu_plugin_tb_trans_cb(CPUState *cpu, struct qemu_plugin_tb *tb)
{
struct qemu_plugin_cb *cb, *next;
enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_TB_TRANS;
/* no plugin_mask check here; caller should have checked */
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_tb_trans_cb_t func = cb->f.vcpu_tb_trans;
func(cb->ctx->id, tb);
}
}
void
qemu_plugin_vcpu_syscall(CPUState *cpu, int64_t num, uint64_t a1, uint64_t a2,
uint64_t a3, uint64_t a4, uint64_t a5,
uint64_t a6, uint64_t a7, uint64_t a8)
{
struct qemu_plugin_cb *cb, *next;
enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_SYSCALL;
if (!test_bit(ev, cpu->plugin_mask)) {
return;
}
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_syscall_cb_t func = cb->f.vcpu_syscall;
func(cb->ctx->id, cpu->cpu_index, num, a1, a2, a3, a4, a5, a6, a7, a8);
}
}
void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)
{
struct qemu_plugin_cb *cb, *next;
enum qemu_plugin_event ev = QEMU_PLUGIN_EV_VCPU_SYSCALL_RET;
if (!test_bit(ev, cpu->plugin_mask)) {
return;
}
QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) {
qemu_plugin_vcpu_syscall_ret_cb_t func = cb->f.vcpu_syscall_ret;
func(cb->ctx->id, cpu->cpu_index, num, ret);
}
}
void qemu_plugin_vcpu_idle_cb(CPUState *cpu)
{
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_IDLE);
}
void qemu_plugin_vcpu_resume_cb(CPUState *cpu)
{
plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_RESUME);
}
void qemu_plugin_register_vcpu_idle_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_IDLE, cb);
}
void qemu_plugin_register_vcpu_resume_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_RESUME, cb);
}
void qemu_plugin_register_flush_cb(qemu_plugin_id_t id,
qemu_plugin_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_FLUSH, cb);
}
static bool free_dyn_cb_arr(void *p, uint32_t h, void *userp)
{
g_array_free((GArray *) p, true);
return true;
}
void qemu_plugin_flush_cb(void)
{
qht_iter_remove(&plugin.dyn_cb_arr_ht, free_dyn_cb_arr, NULL);
qht_reset(&plugin.dyn_cb_arr_ht);
plugin_cb__simple(QEMU_PLUGIN_EV_FLUSH);
}
void exec_inline_op(struct qemu_plugin_dyn_cb *cb)
{
uint64_t *val = cb->userp;
switch (cb->inline_insn.op) {
case QEMU_PLUGIN_INLINE_ADD_U64:
*val += cb->inline_insn.imm;
break;
default:
g_assert_not_reached();
}
}
void qemu_plugin_vcpu_mem_cb(CPUState *cpu, uint64_t vaddr, uint32_t info)
{
GArray *arr = cpu->plugin_mem_cbs;
size_t i;
if (arr == NULL) {
return;
}
for (i = 0; i < arr->len; i++) {
struct qemu_plugin_dyn_cb *cb =
&g_array_index(arr, struct qemu_plugin_dyn_cb, i);
int w = !!(info & TRACE_MEM_ST) + 1;
if (!(w & cb->rw)) {
break;
}
switch (cb->type) {
case PLUGIN_CB_REGULAR:
cb->f.vcpu_mem(cpu->cpu_index, info, vaddr, cb->userp);
break;
case PLUGIN_CB_INLINE:
exec_inline_op(cb);
break;
default:
g_assert_not_reached();
}
}
}
void qemu_plugin_atexit_cb(void)
{
plugin_cb__udata(QEMU_PLUGIN_EV_ATEXIT);
}
void qemu_plugin_register_atexit_cb(qemu_plugin_id_t id,
qemu_plugin_udata_cb_t cb,
void *udata)
{
plugin_register_cb_udata(id, QEMU_PLUGIN_EV_ATEXIT, cb, udata);
}
/*
* Call this function after longjmp'ing to the main loop. It's possible that the
* last instruction of a TB might have used helpers, and therefore the
* "disable" instruction will never execute because it ended up as dead code.
*/
void qemu_plugin_disable_mem_helpers(CPUState *cpu)
{
cpu->plugin_mem_cbs = NULL;
}
static bool plugin_dyn_cb_arr_cmp(const void *ap, const void *bp)
{
return ap == bp;
}
static void __attribute__((__constructor__)) plugin_init(void)
{
int i;
for (i = 0; i < QEMU_PLUGIN_EV_MAX; i++) {
QLIST_INIT(&plugin.cb_lists[i]);
}
qemu_rec_mutex_init(&plugin.lock);
plugin.id_ht = g_hash_table_new(g_int64_hash, g_int64_equal);
plugin.cpu_ht = g_hash_table_new(g_int_hash, g_int_equal);
QTAILQ_INIT(&plugin.ctxs);
qht_init(&plugin.dyn_cb_arr_ht, plugin_dyn_cb_arr_cmp, 16,
QHT_MODE_AUTO_RESIZE);
atexit(qemu_plugin_atexit_cb);
}

362
plugins/loader.c Normal file
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/*
* QEMU Plugin Core Loader Code
*
* This is the code responsible for loading and unloading the plugins.
* Aside from the basic housekeeping tasks we also need to ensure any
* generated code is flushed when we remove a plugin so we cannot end
* up calling and unloaded helper function.
*
* Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
* Copyright (C) 2019, Linaro
*
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
#include "qapi/error.h"
#include "qemu/option.h"
#include "qemu/rcu_queue.h"
#include "qemu/qht.h"
#include "qemu/bitmap.h"
#include "qemu/xxhash.h"
#include "qemu/plugin.h"
#include "hw/core/cpu.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "plugin.h"
/*
* For convenience we use a bitmap for plugin.mask, but really all we need is a
* u32, which is what we store in TranslationBlock.
*/
QEMU_BUILD_BUG_ON(QEMU_PLUGIN_EV_MAX > 32);
struct qemu_plugin_desc {
char *path;
char **argv;
QTAILQ_ENTRY(qemu_plugin_desc) entry;
int argc;
};
struct qemu_plugin_parse_arg {
QemuPluginList *head;
struct qemu_plugin_desc *curr;
};
QemuOptsList qemu_plugin_opts = {
.name = "plugin",
.implied_opt_name = "file",
.head = QTAILQ_HEAD_INITIALIZER(qemu_plugin_opts.head),
.desc = {
/* do our own parsing to support multiple plugins */
{ /* end of list */ }
},
};
typedef int (*qemu_plugin_install_func_t)(qemu_plugin_id_t, int, char **);
extern struct qemu_plugin_state plugin;
void qemu_plugin_add_dyn_cb_arr(GArray *arr)
{
uint32_t hash = qemu_xxhash2((uint64_t)(uintptr_t)arr);
bool inserted;
inserted = qht_insert(&plugin.dyn_cb_arr_ht, arr, hash, NULL);
g_assert(inserted);
}
static struct qemu_plugin_desc *plugin_find_desc(QemuPluginList *head,
const char *path)
{
struct qemu_plugin_desc *desc;
QTAILQ_FOREACH(desc, head, entry) {
if (strcmp(desc->path, path) == 0) {
return desc;
}
}
return NULL;
}
static int plugin_add(void *opaque, const char *name, const char *value,
Error **errp)
{
struct qemu_plugin_parse_arg *arg = opaque;
struct qemu_plugin_desc *p;
if (strcmp(name, "file") == 0) {
if (strcmp(value, "") == 0) {
error_setg(errp, "requires a non-empty argument");
return 1;
}
p = plugin_find_desc(arg->head, value);
if (p == NULL) {
p = g_new0(struct qemu_plugin_desc, 1);
p->path = g_strdup(value);
QTAILQ_INSERT_TAIL(arg->head, p, entry);
}
arg->curr = p;
} else if (strcmp(name, "arg") == 0) {
if (arg->curr == NULL) {
error_setg(errp, "missing earlier '-plugin file=' option");
return 1;
}
p = arg->curr;
p->argc++;
p->argv = g_realloc_n(p->argv, p->argc, sizeof(char *));
p->argv[p->argc - 1] = g_strdup(value);
} else {
error_setg(errp, "-plugin: unexpected parameter '%s'; ignored", name);
}
return 0;
}
void qemu_plugin_opt_parse(const char *optarg, QemuPluginList *head)
{
struct qemu_plugin_parse_arg arg;
QemuOpts *opts;
opts = qemu_opts_parse_noisily(qemu_find_opts("plugin"), optarg, true);
if (opts == NULL) {
exit(1);
}
arg.head = head;
arg.curr = NULL;
qemu_opt_foreach(opts, plugin_add, &arg, &error_fatal);
qemu_opts_del(opts);
}
/*
* From: https://en.wikipedia.org/wiki/Xorshift
* This is faster than rand_r(), and gives us a wider range (RAND_MAX is only
* guaranteed to be >= INT_MAX).
*/
static uint64_t xorshift64star(uint64_t x)
{
x ^= x >> 12; /* a */
x ^= x << 25; /* b */
x ^= x >> 27; /* c */
return x * UINT64_C(2685821657736338717);
}
static int plugin_load(struct qemu_plugin_desc *desc)
{
qemu_plugin_install_func_t install;
struct qemu_plugin_ctx *ctx;
gpointer sym;
int rc;
ctx = qemu_memalign(qemu_dcache_linesize, sizeof(*ctx));
memset(ctx, 0, sizeof(*ctx));
ctx->desc = desc;
ctx->handle = g_module_open(desc->path, G_MODULE_BIND_LOCAL);
if (ctx->handle == NULL) {
error_report("%s: %s", __func__, g_module_error());
goto err_dlopen;
}
if (!g_module_symbol(ctx->handle, "qemu_plugin_install", &sym)) {
error_report("%s: %s", __func__, g_module_error());
goto err_symbol;
}
install = (qemu_plugin_install_func_t) sym;
/* symbol was found; it could be NULL though */
if (install == NULL) {
error_report("%s: %s: qemu_plugin_install is NULL",
__func__, desc->path);
goto err_symbol;
}
qemu_rec_mutex_lock(&plugin.lock);
/* find an unused random id with &ctx as the seed */
ctx->id = (uint64_t)(uintptr_t)ctx;
for (;;) {
void *existing;
ctx->id = xorshift64star(ctx->id);
existing = g_hash_table_lookup(plugin.id_ht, &ctx->id);
if (likely(existing == NULL)) {
bool success;
success = g_hash_table_insert(plugin.id_ht, &ctx->id, &ctx->id);
g_assert(success);
break;
}
}
QTAILQ_INSERT_TAIL(&plugin.ctxs, ctx, entry);
ctx->installing = true;
rc = install(ctx->id, desc->argc, desc->argv);
ctx->installing = false;
if (rc) {
error_report("%s: qemu_plugin_install returned error code %d",
__func__, rc);
/*
* we cannot rely on the plugin doing its own cleanup, so
* call a full uninstall if the plugin did not yet call it.
*/
if (!ctx->uninstalling) {
plugin_reset_uninstall(ctx->id, NULL, false);
}
}
qemu_rec_mutex_unlock(&plugin.lock);
return rc;
err_symbol:
err_dlopen:
qemu_vfree(ctx);
return 1;
}
/* call after having removed @desc from the list */
static void plugin_desc_free(struct qemu_plugin_desc *desc)
{
int i;
for (i = 0; i < desc->argc; i++) {
g_free(desc->argv[i]);
}
g_free(desc->argv);
g_free(desc->path);
g_free(desc);
}
/**
* qemu_plugin_load_list - load a list of plugins
* @head: head of the list of descriptors of the plugins to be loaded
*
* Returns 0 if all plugins in the list are installed, !0 otherwise.
*
* Note: the descriptor of each successfully installed plugin is removed
* from the list given by @head.
*/
int qemu_plugin_load_list(QemuPluginList *head)
{
struct qemu_plugin_desc *desc, *next;
QTAILQ_FOREACH_SAFE(desc, head, entry, next) {
int err;
err = plugin_load(desc);
if (err) {
return err;
}
QTAILQ_REMOVE(head, desc, entry);
}
return 0;
}
struct qemu_plugin_reset_data {
struct qemu_plugin_ctx *ctx;
qemu_plugin_simple_cb_t cb;
bool reset;
};
static void plugin_reset_destroy__locked(struct qemu_plugin_reset_data *data)
{
struct qemu_plugin_ctx *ctx = data->ctx;
enum qemu_plugin_event ev;
bool success;
/*
* After updating the subscription lists there is no need to wait for an RCU
* grace period to elapse, because right now we either are in a "safe async"
* work environment (i.e. all vCPUs are asleep), or no vCPUs have yet been
* created.
*/
for (ev = 0; ev < QEMU_PLUGIN_EV_MAX; ev++) {
plugin_unregister_cb__locked(ctx, ev);
}
if (data->reset) {
g_assert(ctx->resetting);
if (data->cb) {
data->cb(ctx->id);
}
ctx->resetting = false;
g_free(data);
return;
}
g_assert(ctx->uninstalling);
/* we cannot dlclose if we are going to return to plugin code */
if (ctx->installing) {
error_report("Calling qemu_plugin_uninstall from the install function "
"is a bug. Instead, return !0 from the install function.");
abort();
}
success = g_hash_table_remove(plugin.id_ht, &ctx->id);
g_assert(success);
QTAILQ_REMOVE(&plugin.ctxs, ctx, entry);
if (data->cb) {
data->cb(ctx->id);
}
if (!g_module_close(ctx->handle)) {
warn_report("%s: %s", __func__, g_module_error());
}
plugin_desc_free(ctx->desc);
qemu_vfree(ctx);
g_free(data);
}
static void plugin_reset_destroy(struct qemu_plugin_reset_data *data)
{
qemu_rec_mutex_lock(&plugin.lock);
plugin_reset_destroy__locked(data);
qemu_rec_mutex_lock(&plugin.lock);
}
static void plugin_flush_destroy(CPUState *cpu, run_on_cpu_data arg)
{
struct qemu_plugin_reset_data *data = arg.host_ptr;
g_assert(cpu_in_exclusive_context(cpu));
tb_flush(cpu);
plugin_reset_destroy(data);
}
void plugin_reset_uninstall(qemu_plugin_id_t id,
qemu_plugin_simple_cb_t cb,
bool reset)
{
struct qemu_plugin_reset_data *data;
struct qemu_plugin_ctx *ctx;
qemu_rec_mutex_lock(&plugin.lock);
ctx = plugin_id_to_ctx_locked(id);
if (ctx->uninstalling || (reset && ctx->resetting)) {
qemu_rec_mutex_unlock(&plugin.lock);
return;
}
ctx->resetting = reset;
ctx->uninstalling = !reset;
qemu_rec_mutex_unlock(&plugin.lock);
data = g_new(struct qemu_plugin_reset_data, 1);
data->ctx = ctx;
data->cb = cb;
data->reset = reset;
/*
* Only flush the code cache if the vCPUs have been created. If so,
* current_cpu must be non-NULL.
*/
if (current_cpu) {
async_safe_run_on_cpu(current_cpu, plugin_flush_destroy,
RUN_ON_CPU_HOST_PTR(data));
} else {
/*
* If current_cpu isn't set, then we don't have yet any vCPU threads
* and we therefore can remove the callbacks synchronously.
*/
plugin_reset_destroy(data);
}
}

97
plugins/plugin.h Normal file
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/*
* Plugin Shared Internal Functions
*
* Copyright (C) 2019, Linaro
*
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef _PLUGIN_INTERNAL_H_
#define _PLUGIN_INTERNAL_H_
#include <gmodule.h>
/* global state */
struct qemu_plugin_state {
QTAILQ_HEAD(, qemu_plugin_ctx) ctxs;
QLIST_HEAD(, qemu_plugin_cb) cb_lists[QEMU_PLUGIN_EV_MAX];
/*
* Use the HT as a hash map by inserting k == v, which saves memory as
* documented by GLib. The parent struct is obtained with container_of().
*/
GHashTable *id_ht;
/*
* Use the HT as a hash map. Note that we could use a list here,
* but with the HT we avoid adding a field to CPUState.
*/
GHashTable *cpu_ht;
DECLARE_BITMAP(mask, QEMU_PLUGIN_EV_MAX);
/*
* @lock protects the struct as well as ctx->uninstalling.
* The lock must be acquired by all API ops.
* The lock is recursive, which greatly simplifies things, e.g.
* callback registration from qemu_plugin_vcpu_for_each().
*/
QemuRecMutex lock;
/*
* HT of callbacks invoked from helpers. All entries are freed when
* the code cache is flushed.
*/
struct qht dyn_cb_arr_ht;
};
struct qemu_plugin_ctx {
GModule *handle;
qemu_plugin_id_t id;
struct qemu_plugin_cb *callbacks[QEMU_PLUGIN_EV_MAX];
QTAILQ_ENTRY(qemu_plugin_ctx) entry;
/*
* keep a reference to @desc until uninstall, so that plugins do not have
* to strdup plugin args.
*/
struct qemu_plugin_desc *desc;
bool installing;
bool uninstalling;
bool resetting;
};
struct qemu_plugin_ctx *plugin_id_to_ctx_locked(qemu_plugin_id_t id);
void plugin_register_inline_op(GArray **arr,
enum qemu_plugin_mem_rw rw,
enum qemu_plugin_op op, void *ptr,
uint64_t imm);
void plugin_reset_uninstall(qemu_plugin_id_t id,
qemu_plugin_simple_cb_t cb,
bool reset);
void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func);
void plugin_unregister_cb__locked(struct qemu_plugin_ctx *ctx,
enum qemu_plugin_event ev);
void
plugin_register_cb_udata(qemu_plugin_id_t id, enum qemu_plugin_event ev,
void *func, void *udata);
void
plugin_register_dyn_cb__udata(GArray **arr,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags, void *udata);
void plugin_register_vcpu_mem_cb(GArray **arr,
void *cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_mem_rw rw,
void *udata);
void exec_inline_op(struct qemu_plugin_dyn_cb *cb);
#endif /* _PLUGIN_INTERNAL_H_ */