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qemu/accel/tcg/plugin-gen.c
Alex Bennée 453d50ce75 accel/tcg: re-factor plugin_inject_cb so we can assert insn_idx is valid 
Coverity doesn't know enough about how we have arranged our plugin TCG
ops to know we will always have incremented insn_idx before injecting
the callback. Let us assert it for the benefit of Coverity and protect
ourselves from accidentally breaking the assumption and triggering
harder to grok errors deeper in the code if we attempt a negative
indexed array lookup.

However to get to this point we re-factor the code and remove the
second hand instruction boundary detection in favour of scanning the
full set of ops and using the existing INDEX_op_insn_start to cleanly
detect when the instruction has started. As we no longer need the
plugin specific list of ops we delete that.

My initial benchmarks shows no discernible impact of dropping the
plugin specific ops list.

Fixes: Coverity 1459509
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210917162332.3511179-12-alex.bennee@linaro.org>
2021-10-12 08:38:10 +01:00

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/*
* plugin-gen.c - TCG-related bits of plugin infrastructure
*
* Copyright (C) 2018, Emilio G. Cota <cota@braap.org>
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* We support instrumentation at an instruction granularity. That is,
* if a plugin wants to instrument the memory accesses performed by a
* particular instruction, it can just do that instead of instrumenting
* all memory accesses. Thus, in order to do this we first have to
* translate a TB, so that plugins can decide what/where to instrument.
*
* Injecting the desired instrumentation could be done with a second
* translation pass that combined the instrumentation requests, but that
* would be ugly and inefficient since we would decode the guest code twice.
* Instead, during TB translation we add "empty" instrumentation calls for all
* possible instrumentation events, and then once we collect the instrumentation
* requests from plugins, we either "fill in" those empty events or remove them
* if they have no requests.
*
* When "filling in" an event we first copy the empty callback's TCG ops. This
* might seem unnecessary, but it is done to support an arbitrary number
* of callbacks per event. Take for example a regular instruction callback.
* We first generate a callback to an empty helper function. Then, if two
* plugins register one callback each for this instruction, we make two copies
* of the TCG ops generated for the empty callback, substituting the function
* pointer that points to the empty helper function with the plugins' desired
* callback functions. After that we remove the empty callback's ops.
*
* Note that the location in TCGOp.args[] of the pointer to a helper function
* varies across different guest and host architectures. Instead of duplicating
* the logic that figures this out, we rely on the fact that the empty
* callbacks point to empty functions that are unique pointers in the program.
* Thus, to find the right location we just have to look for a match in
* TCGOp.args[]. This is the main reason why we first copy an empty callback's
* TCG ops and then fill them in; regardless of whether we have one or many
* callbacks for that event, the logic to add all of them is the same.
*
* When generating more than one callback per event, we make a small
* optimization to avoid generating redundant operations. For instance, for the
* second and all subsequent callbacks of an event, we do not need to reload the
* CPU's index into a TCG temp, since the first callback did it already.
*/
#include "qemu/osdep.h"
#include "tcg/tcg.h"
#include "tcg/tcg-op.h"
#include "exec/exec-all.h"
#include "exec/plugin-gen.h"
#include "exec/translator.h"
#ifdef CONFIG_SOFTMMU
# define CONFIG_SOFTMMU_GATE 1
#else
# define CONFIG_SOFTMMU_GATE 0
#endif
/*
* plugin_cb_start TCG op args[]:
* 0: enum plugin_gen_from
* 1: enum plugin_gen_cb
* 2: set to 1 for mem callback that is a write, 0 otherwise.
*/
enum plugin_gen_from {
PLUGIN_GEN_FROM_TB,
PLUGIN_GEN_FROM_INSN,
PLUGIN_GEN_FROM_MEM,
PLUGIN_GEN_AFTER_INSN,
PLUGIN_GEN_N_FROMS,
};
enum plugin_gen_cb {
PLUGIN_GEN_CB_UDATA,
PLUGIN_GEN_CB_INLINE,
PLUGIN_GEN_CB_MEM,
PLUGIN_GEN_ENABLE_MEM_HELPER,
PLUGIN_GEN_DISABLE_MEM_HELPER,
PLUGIN_GEN_N_CBS,
};
/*
* These helpers are stubs that get dynamically switched out for calls
* direct to the plugin if they are subscribed to.
*/
void HELPER(plugin_vcpu_udata_cb)(uint32_t cpu_index, void *udata)
{ }
void HELPER(plugin_vcpu_mem_cb)(unsigned int vcpu_index,
qemu_plugin_meminfo_t info, uint64_t vaddr,
void *userdata)
{ }
static void do_gen_mem_cb(TCGv vaddr, uint32_t info)
{
TCGv_i32 cpu_index = tcg_temp_new_i32();
TCGv_i32 meminfo = tcg_const_i32(info);
TCGv_i64 vaddr64 = tcg_temp_new_i64();
TCGv_ptr udata = tcg_const_ptr(NULL);
tcg_gen_ld_i32(cpu_index, cpu_env,
-offsetof(ArchCPU, env) + offsetof(CPUState, cpu_index));
tcg_gen_extu_tl_i64(vaddr64, vaddr);
gen_helper_plugin_vcpu_mem_cb(cpu_index, meminfo, vaddr64, udata);
tcg_temp_free_ptr(udata);
tcg_temp_free_i64(vaddr64);
tcg_temp_free_i32(meminfo);
tcg_temp_free_i32(cpu_index);
}
static void gen_empty_udata_cb(void)
{
TCGv_i32 cpu_index = tcg_temp_new_i32();
TCGv_ptr udata = tcg_const_ptr(NULL); /* will be overwritten later */
tcg_gen_ld_i32(cpu_index, cpu_env,
-offsetof(ArchCPU, env) + offsetof(CPUState, cpu_index));
gen_helper_plugin_vcpu_udata_cb(cpu_index, udata);
tcg_temp_free_ptr(udata);
tcg_temp_free_i32(cpu_index);
}
/*
* For now we only support addi_i64.
* When we support more ops, we can generate one empty inline cb for each.
*/
static void gen_empty_inline_cb(void)
{
TCGv_i64 val = tcg_temp_new_i64();
TCGv_ptr ptr = tcg_const_ptr(NULL); /* overwritten later */
tcg_gen_ld_i64(val, ptr, 0);
/* pass an immediate != 0 so that it doesn't get optimized away */
tcg_gen_addi_i64(val, val, 0xdeadface);
tcg_gen_st_i64(val, ptr, 0);
tcg_temp_free_ptr(ptr);
tcg_temp_free_i64(val);
}
static void gen_empty_mem_cb(TCGv addr, uint32_t info)
{
do_gen_mem_cb(addr, info);
}
/*
* Share the same function for enable/disable. When enabling, the NULL
* pointer will be overwritten later.
*/
static void gen_empty_mem_helper(void)
{
TCGv_ptr ptr;
ptr = tcg_const_ptr(NULL);
tcg_gen_st_ptr(ptr, cpu_env, offsetof(CPUState, plugin_mem_cbs) -
offsetof(ArchCPU, env));
tcg_temp_free_ptr(ptr);
}
static void gen_plugin_cb_start(enum plugin_gen_from from,
enum plugin_gen_cb type, unsigned wr)
{
tcg_gen_plugin_cb_start(from, type, wr);
}
static void gen_wrapped(enum plugin_gen_from from,
enum plugin_gen_cb type, void (*func)(void))
{
gen_plugin_cb_start(from, type, 0);
func();
tcg_gen_plugin_cb_end();
}
static void plugin_gen_empty_callback(enum plugin_gen_from from)
{
switch (from) {
case PLUGIN_GEN_AFTER_INSN:
gen_wrapped(from, PLUGIN_GEN_DISABLE_MEM_HELPER,
gen_empty_mem_helper);
break;
case PLUGIN_GEN_FROM_INSN:
/*
* Note: plugin_gen_inject() relies on ENABLE_MEM_HELPER being
* the first callback of an instruction
*/
gen_wrapped(from, PLUGIN_GEN_ENABLE_MEM_HELPER,
gen_empty_mem_helper);
/* fall through */
case PLUGIN_GEN_FROM_TB:
gen_wrapped(from, PLUGIN_GEN_CB_UDATA, gen_empty_udata_cb);
gen_wrapped(from, PLUGIN_GEN_CB_INLINE, gen_empty_inline_cb);
break;
default:
g_assert_not_reached();
}
}
union mem_gen_fn {
void (*mem_fn)(TCGv, uint32_t);
void (*inline_fn)(void);
};
static void gen_mem_wrapped(enum plugin_gen_cb type,
const union mem_gen_fn *f, TCGv addr,
uint32_t info, bool is_mem)
{
enum qemu_plugin_mem_rw rw = get_plugin_meminfo_rw(info);
gen_plugin_cb_start(PLUGIN_GEN_FROM_MEM, type, rw);
if (is_mem) {
f->mem_fn(addr, info);
} else {
f->inline_fn();
}
tcg_gen_plugin_cb_end();
}
void plugin_gen_empty_mem_callback(TCGv addr, uint32_t info)
{
union mem_gen_fn fn;
fn.mem_fn = gen_empty_mem_cb;
gen_mem_wrapped(PLUGIN_GEN_CB_MEM, &fn, addr, info, true);
fn.inline_fn = gen_empty_inline_cb;
gen_mem_wrapped(PLUGIN_GEN_CB_INLINE, &fn, 0, info, false);
}
static TCGOp *find_op(TCGOp *op, TCGOpcode opc)
{
while (op) {
if (op->opc == opc) {
return op;
}
op = QTAILQ_NEXT(op, link);
}
return NULL;
}
static TCGOp *rm_ops_range(TCGOp *begin, TCGOp *end)
{
TCGOp *ret = QTAILQ_NEXT(end, link);
QTAILQ_REMOVE_SEVERAL(&tcg_ctx->ops, begin, end, link);
return ret;
}
/* remove all ops until (and including) plugin_cb_end */
static TCGOp *rm_ops(TCGOp *op)
{
TCGOp *end_op = find_op(op, INDEX_op_plugin_cb_end);
tcg_debug_assert(end_op);
return rm_ops_range(op, end_op);
}
static TCGOp *copy_op_nocheck(TCGOp **begin_op, TCGOp *op)
{
*begin_op = QTAILQ_NEXT(*begin_op, link);
tcg_debug_assert(*begin_op);
op = tcg_op_insert_after(tcg_ctx, op, (*begin_op)->opc);
memcpy(op->args, (*begin_op)->args, sizeof(op->args));
return op;
}
static TCGOp *copy_op(TCGOp **begin_op, TCGOp *op, TCGOpcode opc)
{
op = copy_op_nocheck(begin_op, op);
tcg_debug_assert((*begin_op)->opc == opc);
return op;
}
static TCGOp *copy_extu_i32_i64(TCGOp **begin_op, TCGOp *op)
{
if (TCG_TARGET_REG_BITS == 32) {
/* mov_i32 */
op = copy_op(begin_op, op, INDEX_op_mov_i32);
/* mov_i32 w/ $0 */
op = copy_op(begin_op, op, INDEX_op_mov_i32);
} else {
/* extu_i32_i64 */
op = copy_op(begin_op, op, INDEX_op_extu_i32_i64);
}
return op;
}
static TCGOp *copy_mov_i64(TCGOp **begin_op, TCGOp *op)
{
if (TCG_TARGET_REG_BITS == 32) {
/* 2x mov_i32 */
op = copy_op(begin_op, op, INDEX_op_mov_i32);
op = copy_op(begin_op, op, INDEX_op_mov_i32);
} else {
/* mov_i64 */
op = copy_op(begin_op, op, INDEX_op_mov_i64);
}
return op;
}
static TCGOp *copy_const_ptr(TCGOp **begin_op, TCGOp *op, void *ptr)
{
if (UINTPTR_MAX == UINT32_MAX) {
/* mov_i32 */
op = copy_op(begin_op, op, INDEX_op_mov_i32);
op->args[1] = tcgv_i32_arg(tcg_constant_i32((uintptr_t)ptr));
} else {
/* mov_i64 */
op = copy_op(begin_op, op, INDEX_op_mov_i64);
op->args[1] = tcgv_i64_arg(tcg_constant_i64((uintptr_t)ptr));
}
return op;
}
static TCGOp *copy_extu_tl_i64(TCGOp **begin_op, TCGOp *op)
{
if (TARGET_LONG_BITS == 32) {
/* extu_i32_i64 */
op = copy_extu_i32_i64(begin_op, op);
} else {
/* mov_i64 */
op = copy_mov_i64(begin_op, op);
}
return op;
}
static TCGOp *copy_ld_i64(TCGOp **begin_op, TCGOp *op)
{
if (TCG_TARGET_REG_BITS == 32) {
/* 2x ld_i32 */
op = copy_op(begin_op, op, INDEX_op_ld_i32);
op = copy_op(begin_op, op, INDEX_op_ld_i32);
} else {
/* ld_i64 */
op = copy_op(begin_op, op, INDEX_op_ld_i64);
}
return op;
}
static TCGOp *copy_st_i64(TCGOp **begin_op, TCGOp *op)
{
if (TCG_TARGET_REG_BITS == 32) {
/* 2x st_i32 */
op = copy_op(begin_op, op, INDEX_op_st_i32);
op = copy_op(begin_op, op, INDEX_op_st_i32);
} else {
/* st_i64 */
op = copy_op(begin_op, op, INDEX_op_st_i64);
}
return op;
}
static TCGOp *copy_add_i64(TCGOp **begin_op, TCGOp *op, uint64_t v)
{
if (TCG_TARGET_REG_BITS == 32) {
/* all 32-bit backends must implement add2_i32 */
g_assert(TCG_TARGET_HAS_add2_i32);
op = copy_op(begin_op, op, INDEX_op_add2_i32);
op->args[4] = tcgv_i32_arg(tcg_constant_i32(v));
op->args[5] = tcgv_i32_arg(tcg_constant_i32(v >> 32));
} else {
op = copy_op(begin_op, op, INDEX_op_add_i64);
op->args[2] = tcgv_i64_arg(tcg_constant_i64(v));
}
return op;
}
static TCGOp *copy_st_ptr(TCGOp **begin_op, TCGOp *op)
{
if (UINTPTR_MAX == UINT32_MAX) {
/* st_i32 */
op = copy_op(begin_op, op, INDEX_op_st_i32);
} else {
/* st_i64 */
op = copy_st_i64(begin_op, op);
}
return op;
}
static TCGOp *copy_call(TCGOp **begin_op, TCGOp *op, void *empty_func,
void *func, int *cb_idx)
{
/* copy all ops until the call */
do {
op = copy_op_nocheck(begin_op, op);
} while (op->opc != INDEX_op_call);
/* fill in the op call */
op->param1 = (*begin_op)->param1;
op->param2 = (*begin_op)->param2;
tcg_debug_assert(op->life == 0);
if (*cb_idx == -1) {
int i;
/*
* Instead of working out the position of the callback in args[], just
* look for @empty_func, since it should be a unique pointer.
*/
for (i = 0; i < MAX_OPC_PARAM_ARGS; i++) {
if ((uintptr_t)(*begin_op)->args[i] == (uintptr_t)empty_func) {
*cb_idx = i;
break;
}
}
tcg_debug_assert(i < MAX_OPC_PARAM_ARGS);
}
op->args[*cb_idx] = (uintptr_t)func;
op->args[*cb_idx + 1] = (*begin_op)->args[*cb_idx + 1];
return op;
}
/*
* When we append/replace ops here we are sensitive to changing patterns of
* TCGOps generated by the tcg_gen_FOO calls when we generated the
* empty callbacks. This will assert very quickly in a debug build as
* we assert the ops we are replacing are the correct ones.
*/
static TCGOp *append_udata_cb(const struct qemu_plugin_dyn_cb *cb,
TCGOp *begin_op, TCGOp *op, int *cb_idx)
{
/* const_ptr */
op = copy_const_ptr(&begin_op, op, cb->userp);
/* copy the ld_i32, but note that we only have to copy it once */
begin_op = QTAILQ_NEXT(begin_op, link);
tcg_debug_assert(begin_op && begin_op->opc == INDEX_op_ld_i32);
if (*cb_idx == -1) {
op = tcg_op_insert_after(tcg_ctx, op, INDEX_op_ld_i32);
memcpy(op->args, begin_op->args, sizeof(op->args));
}
/* call */
op = copy_call(&begin_op, op, HELPER(plugin_vcpu_udata_cb),
cb->f.vcpu_udata, cb_idx);
return op;
}
static TCGOp *append_inline_cb(const struct qemu_plugin_dyn_cb *cb,
TCGOp *begin_op, TCGOp *op,
int *unused)
{
/* const_ptr */
op = copy_const_ptr(&begin_op, op, cb->userp);
/* ld_i64 */
op = copy_ld_i64(&begin_op, op);
/* add_i64 */
op = copy_add_i64(&begin_op, op, cb->inline_insn.imm);
/* st_i64 */
op = copy_st_i64(&begin_op, op);
return op;
}
static TCGOp *append_mem_cb(const struct qemu_plugin_dyn_cb *cb,
TCGOp *begin_op, TCGOp *op, int *cb_idx)
{
enum plugin_gen_cb type = begin_op->args[1];
tcg_debug_assert(type == PLUGIN_GEN_CB_MEM);
/* const_i32 == mov_i32 ("info", so it remains as is) */
op = copy_op(&begin_op, op, INDEX_op_mov_i32);
/* const_ptr */
op = copy_const_ptr(&begin_op, op, cb->userp);
/* copy the ld_i32, but note that we only have to copy it once */
begin_op = QTAILQ_NEXT(begin_op, link);
tcg_debug_assert(begin_op && begin_op->opc == INDEX_op_ld_i32);
if (*cb_idx == -1) {
op = tcg_op_insert_after(tcg_ctx, op, INDEX_op_ld_i32);
memcpy(op->args, begin_op->args, sizeof(op->args));
}
/* extu_tl_i64 */
op = copy_extu_tl_i64(&begin_op, op);
if (type == PLUGIN_GEN_CB_MEM) {
/* call */
op = copy_call(&begin_op, op, HELPER(plugin_vcpu_mem_cb),
cb->f.vcpu_udata, cb_idx);
}
return op;
}
typedef TCGOp *(*inject_fn)(const struct qemu_plugin_dyn_cb *cb,
TCGOp *begin_op, TCGOp *op, int *intp);
typedef bool (*op_ok_fn)(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb);
static bool op_ok(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb)
{
return true;
}
static bool op_rw(const TCGOp *op, const struct qemu_plugin_dyn_cb *cb)
{
int w;
w = op->args[2];
return !!(cb->rw & (w + 1));
}
static void inject_cb_type(const GArray *cbs, TCGOp *begin_op,
inject_fn inject, op_ok_fn ok)
{
TCGOp *end_op;
TCGOp *op;
int cb_idx = -1;
int i;
if (!cbs || cbs->len == 0) {
rm_ops(begin_op);
return;
}
end_op = find_op(begin_op, INDEX_op_plugin_cb_end);
tcg_debug_assert(end_op);
op = end_op;
for (i = 0; i < cbs->len; i++) {
struct qemu_plugin_dyn_cb *cb =
&g_array_index(cbs, struct qemu_plugin_dyn_cb, i);
if (!ok(begin_op, cb)) {
continue;
}
op = inject(cb, begin_op, op, &cb_idx);
}
rm_ops_range(begin_op, end_op);
}
static void
inject_udata_cb(const GArray *cbs, TCGOp *begin_op)
{
inject_cb_type(cbs, begin_op, append_udata_cb, op_ok);
}
static void
inject_inline_cb(const GArray *cbs, TCGOp *begin_op, op_ok_fn ok)
{
inject_cb_type(cbs, begin_op, append_inline_cb, ok);
}
static void
inject_mem_cb(const GArray *cbs, TCGOp *begin_op)
{
inject_cb_type(cbs, begin_op, append_mem_cb, op_rw);
}
/* we could change the ops in place, but we can reuse more code by copying */
static void inject_mem_helper(TCGOp *begin_op, GArray *arr)
{
TCGOp *orig_op = begin_op;
TCGOp *end_op;
TCGOp *op;
end_op = find_op(begin_op, INDEX_op_plugin_cb_end);
tcg_debug_assert(end_op);
/* const ptr */
op = copy_const_ptr(&begin_op, end_op, arr);
/* st_ptr */
op = copy_st_ptr(&begin_op, op);
rm_ops_range(orig_op, end_op);
}
/*
* Tracking memory accesses performed from helpers requires extra work.
* If an instruction is emulated with helpers, we do two things:
* (1) copy the CB descriptors, and keep track of it so that they can be
* freed later on, and (2) point CPUState.plugin_mem_cbs to the descriptors, so
* that we can read them at run-time (i.e. when the helper executes).
* This run-time access is performed from qemu_plugin_vcpu_mem_cb.
*
* Note that plugin_gen_disable_mem_helpers undoes (2). Since it
* is possible that the code we generate after the instruction is
* dead, we also add checks before generating tb_exit etc.
*/
static void inject_mem_enable_helper(struct qemu_plugin_insn *plugin_insn,
TCGOp *begin_op)
{
GArray *cbs[2];
GArray *arr;
size_t n_cbs, i;
cbs[0] = plugin_insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR];
cbs[1] = plugin_insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE];
n_cbs = 0;
for (i = 0; i < ARRAY_SIZE(cbs); i++) {
n_cbs += cbs[i]->len;
}
plugin_insn->mem_helper = plugin_insn->calls_helpers && n_cbs;
if (likely(!plugin_insn->mem_helper)) {
rm_ops(begin_op);
return;
}
arr = g_array_sized_new(false, false,
sizeof(struct qemu_plugin_dyn_cb), n_cbs);
for (i = 0; i < ARRAY_SIZE(cbs); i++) {
g_array_append_vals(arr, cbs[i]->data, cbs[i]->len);
}
qemu_plugin_add_dyn_cb_arr(arr);
inject_mem_helper(begin_op, arr);
}
static void inject_mem_disable_helper(struct qemu_plugin_insn *plugin_insn,
TCGOp *begin_op)
{
if (likely(!plugin_insn->mem_helper)) {
rm_ops(begin_op);
return;
}
inject_mem_helper(begin_op, NULL);
}
/* called before finishing a TB with exit_tb, goto_tb or goto_ptr */
void plugin_gen_disable_mem_helpers(void)
{
TCGv_ptr ptr;
if (likely(tcg_ctx->plugin_insn == NULL ||
!tcg_ctx->plugin_insn->mem_helper)) {
return;
}
ptr = tcg_const_ptr(NULL);
tcg_gen_st_ptr(ptr, cpu_env, offsetof(CPUState, plugin_mem_cbs) -
offsetof(ArchCPU, env));
tcg_temp_free_ptr(ptr);
tcg_ctx->plugin_insn->mem_helper = false;
}
static void plugin_gen_tb_udata(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op)
{
inject_udata_cb(ptb->cbs[PLUGIN_CB_REGULAR], begin_op);
}
static void plugin_gen_tb_inline(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op)
{
inject_inline_cb(ptb->cbs[PLUGIN_CB_INLINE], begin_op, op_ok);
}
static void plugin_gen_insn_udata(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op, int insn_idx)
{
struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
inject_udata_cb(insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR], begin_op);
}
static void plugin_gen_insn_inline(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op, int insn_idx)
{
struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
inject_inline_cb(insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
begin_op, op_ok);
}
static void plugin_gen_mem_regular(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op, int insn_idx)
{
struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
inject_mem_cb(insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR], begin_op);
}
static void plugin_gen_mem_inline(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op, int insn_idx)
{
const GArray *cbs;
struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
cbs = insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE];
inject_inline_cb(cbs, begin_op, op_rw);
}
static void plugin_gen_enable_mem_helper(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op, int insn_idx)
{
struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
inject_mem_enable_helper(insn, begin_op);
}
static void plugin_gen_disable_mem_helper(const struct qemu_plugin_tb *ptb,
TCGOp *begin_op, int insn_idx)
{
struct qemu_plugin_insn *insn = g_ptr_array_index(ptb->insns, insn_idx);
inject_mem_disable_helper(insn, begin_op);
}
/* #define DEBUG_PLUGIN_GEN_OPS */
static void pr_ops(void)
{
#ifdef DEBUG_PLUGIN_GEN_OPS
TCGOp *op;
int i = 0;
QTAILQ_FOREACH(op, &tcg_ctx->ops, link) {
const char *name = "";
const char *type = "";
if (op->opc == INDEX_op_plugin_cb_start) {
switch (op->args[0]) {
case PLUGIN_GEN_FROM_TB:
name = "tb";
break;
case PLUGIN_GEN_FROM_INSN:
name = "insn";
break;
case PLUGIN_GEN_FROM_MEM:
name = "mem";
break;
case PLUGIN_GEN_AFTER_INSN:
name = "after insn";
break;
default:
break;
}
switch (op->args[1]) {
case PLUGIN_GEN_CB_UDATA:
type = "udata";
break;
case PLUGIN_GEN_CB_INLINE:
type = "inline";
break;
case PLUGIN_GEN_CB_MEM:
type = "mem";
break;
case PLUGIN_GEN_ENABLE_MEM_HELPER:
type = "enable mem helper";
break;
case PLUGIN_GEN_DISABLE_MEM_HELPER:
type = "disable mem helper";
break;
default:
break;
}
}
printf("op[%2i]: %s %s %s\n", i, tcg_op_defs[op->opc].name, name, type);
i++;
}
#endif
}
static void plugin_gen_inject(const struct qemu_plugin_tb *plugin_tb)
{
TCGOp *op;
int insn_idx = -1;
pr_ops();
QTAILQ_FOREACH(op, &tcg_ctx->ops, link) {
switch (op->opc) {
case INDEX_op_insn_start:
insn_idx++;
break;
case INDEX_op_plugin_cb_start:
{
enum plugin_gen_from from = op->args[0];
enum plugin_gen_cb type = op->args[1];
switch (from) {
case PLUGIN_GEN_FROM_TB:
{
g_assert(insn_idx == -1);
switch (type) {
case PLUGIN_GEN_CB_UDATA:
plugin_gen_tb_udata(plugin_tb, op);
break;
case PLUGIN_GEN_CB_INLINE:
plugin_gen_tb_inline(plugin_tb, op);
break;
default:
g_assert_not_reached();
}
break;
}
case PLUGIN_GEN_FROM_INSN:
{
g_assert(insn_idx >= 0);
switch (type) {
case PLUGIN_GEN_CB_UDATA:
plugin_gen_insn_udata(plugin_tb, op, insn_idx);
break;
case PLUGIN_GEN_CB_INLINE:
plugin_gen_insn_inline(plugin_tb, op, insn_idx);
break;
case PLUGIN_GEN_ENABLE_MEM_HELPER:
plugin_gen_enable_mem_helper(plugin_tb, op, insn_idx);
break;
default:
g_assert_not_reached();
}
break;
}
case PLUGIN_GEN_FROM_MEM:
{
g_assert(insn_idx >= 0);
switch (type) {
case PLUGIN_GEN_CB_MEM:
plugin_gen_mem_regular(plugin_tb, op, insn_idx);
break;
case PLUGIN_GEN_CB_INLINE:
plugin_gen_mem_inline(plugin_tb, op, insn_idx);
break;
default:
g_assert_not_reached();
}
break;
}
case PLUGIN_GEN_AFTER_INSN:
{
g_assert(insn_idx >= 0);
switch (type) {
case PLUGIN_GEN_DISABLE_MEM_HELPER:
plugin_gen_disable_mem_helper(plugin_tb, op, insn_idx);
break;
default:
g_assert_not_reached();
}
break;
}
default:
g_assert_not_reached();
}
break;
}
default:
/* plugins don't care about any other ops */
break;
}
}
pr_ops();
}
bool plugin_gen_tb_start(CPUState *cpu, const TranslationBlock *tb, bool mem_only)
{
struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
bool ret = false;
if (test_bit(QEMU_PLUGIN_EV_VCPU_TB_TRANS, cpu->plugin_mask)) {
ret = true;
ptb->vaddr = tb->pc;
ptb->vaddr2 = -1;
get_page_addr_code_hostp(cpu->env_ptr, tb->pc, &ptb->haddr1);
ptb->haddr2 = NULL;
ptb->mem_only = mem_only;
plugin_gen_empty_callback(PLUGIN_GEN_FROM_TB);
}
return ret;
}
void plugin_gen_insn_start(CPUState *cpu, const DisasContextBase *db)
{
struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
struct qemu_plugin_insn *pinsn;
pinsn = qemu_plugin_tb_insn_get(ptb);
tcg_ctx->plugin_insn = pinsn;
pinsn->vaddr = db->pc_next;
plugin_gen_empty_callback(PLUGIN_GEN_FROM_INSN);
/*
* Detect page crossing to get the new host address.
* Note that we skip this when haddr1 == NULL, e.g. when we're
* fetching instructions from a region not backed by RAM.
*/
if (likely(ptb->haddr1 != NULL && ptb->vaddr2 == -1) &&
unlikely((db->pc_next & TARGET_PAGE_MASK) !=
(db->pc_first & TARGET_PAGE_MASK))) {
get_page_addr_code_hostp(cpu->env_ptr, db->pc_next,
&ptb->haddr2);
ptb->vaddr2 = db->pc_next;
}
if (likely(ptb->vaddr2 == -1)) {
pinsn->haddr = ptb->haddr1 + pinsn->vaddr - ptb->vaddr;
} else {
pinsn->haddr = ptb->haddr2 + pinsn->vaddr - ptb->vaddr2;
}
}
void plugin_gen_insn_end(void)
{
plugin_gen_empty_callback(PLUGIN_GEN_AFTER_INSN);
}
void plugin_gen_tb_end(CPUState *cpu)
{
struct qemu_plugin_tb *ptb = tcg_ctx->plugin_tb;
int i;
/* collect instrumentation requests */
qemu_plugin_tb_trans_cb(cpu, ptb);
/* inject the instrumentation at the appropriate places */
plugin_gen_inject(ptb);
/* clean up */
for (i = 0; i < PLUGIN_N_CB_SUBTYPES; i++) {
if (ptb->cbs[i]) {
g_array_set_size(ptb->cbs[i], 0);
}
}
ptb->n = 0;
tcg_ctx->plugin_insn = NULL;
}
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