unicorn/qemu/cpu-exec.c
Paolo Bonzini 2f4ae94b5c
target-i386: make cpu-qom.h not target specific
Make X86CPU an opaque type within cpu-qom.h, and move all definitions of
private methods, as well as all type definitions that require knowledge
of the layout to cpu.h. This helps making files independent of NEED_CPU_H
if they only need to pass around CPU pointers.

Backports commit 4da6f8d954429c0cd1471d25cb9dbe909607374e from qemu
2018-02-24 00:55:22 -05:00

438 lines
14 KiB
C

/*
* emulator main execution loop
*
* Copyright (c) 2003-2005 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/* Modified for Unicorn Engine by Nguyen Anh Quynh, 2015 */
#include "qemu/osdep.h"
#include "tcg.h"
#include "sysemu/sysemu.h"
#include "exec/address-spaces.h"
#include "exec/tb-hash.h"
#include "uc_priv.h"
/* Execute a TB, and fix up the CPU state afterwards if necessary */
static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)
{
CPUArchState *env = cpu->env_ptr;
TCGContext *tcg_ctx = env->uc->tcg_ctx;
uintptr_t ret;
TranslationBlock *last_tb;
int tb_exit;
uint8_t *tb_ptr = itb->tc_ptr;
// Unicorn: commented out
//qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc,
// "Trace %p [" TARGET_FMT_lx "] %s\n",
// itb->tc_ptr, itb->pc, lookup_symbol(itb->pc));
ret = tcg_qemu_tb_exec(env, tb_ptr);
last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
tb_exit = ret & TB_EXIT_MASK;
//trace_exec_tb_exit(last_tb, tb_exit);
if (tb_exit > TB_EXIT_IDX1) {
/* We didn't start executing this TB (eg because the instruction
* counter hit zero); we must restore the guest PC to the address
* of the start of the TB.
*/
CPUClass *cc = CPU_GET_CLASS(env->uc, cpu);
// Unicorn: commented out
//qemu_log_mask_and_addr(CPU_LOG_EXEC, last_tb->pc,
// "Stopped execution of TB chain before %p ["
// TARGET_FMT_lx "] %s\n",
// last_tb->tc_ptr, last_tb->pc,
// lookup_symbol(last_tb->pc));
if (cc->synchronize_from_tb) {
// avoid sync twice when helper_uc_tracecode() already did this.
if (env->uc->emu_counter <= env->uc->emu_count &&
!env->uc->stop_request && !env->uc->quit_request) {
cc->synchronize_from_tb(cpu, last_tb);
}
} else {
assert(cc->set_pc);
// avoid sync twice when helper_uc_tracecode() already did this.
if (env->uc->emu_counter <= env->uc->emu_count && !env->uc->quit_request) {
cc->set_pc(cpu, last_tb->pc);
}
}
}
if (tb_exit == TB_EXIT_REQUESTED) {
/* We were asked to stop executing TBs (probably a pending
* interrupt. We've now stopped, so clear the flag.
*/
cpu->tcg_exit_req = 0;
}
return ret;
}
static TranslationBlock *tb_find_slow(CPUState *cpu,
target_ulong pc,
target_ulong cs_base,
uint64_t flags)
{
CPUArchState *env = (CPUArchState *)cpu->env_ptr;
TCGContext *tcg_ctx = env->uc->tcg_ctx;
TranslationBlock *tb, **ptb1;
unsigned int h;
tb_page_addr_t phys_pc, phys_page1;
target_ulong virt_page2;
/* find translated block using physical mappings */
phys_pc = get_page_addr_code(env, pc); // qq
if (phys_pc == -1) { // invalid code?
return NULL;
}
phys_page1 = phys_pc & TARGET_PAGE_MASK;
h = tb_phys_hash_func(phys_pc);
ptb1 = &tcg_ctx->tb_ctx.tb_phys_hash[h];
for(;;) {
tb = *ptb1;
if (!tb)
goto not_found;
if (tb->pc == pc &&
tb->page_addr[0] == phys_page1 &&
tb->cs_base == cs_base &&
tb->flags == flags) {
/* check next page if needed */
if (tb->page_addr[1] != -1) {
tb_page_addr_t phys_page2;
virt_page2 = (pc & TARGET_PAGE_MASK) +
TARGET_PAGE_SIZE;
phys_page2 = get_page_addr_code(env, virt_page2);
if (tb->page_addr[1] == phys_page2)
goto found;
} else {
goto found;
}
}
ptb1 = &tb->phys_hash_next;
}
not_found:
/* if no translated code available, then translate it now */
tb = tb_gen_code(cpu, pc, cs_base, (int)flags, 0); // qq
found:
/* Move the last found TB to the head of the list */
if (likely(*ptb1)) {
*ptb1 = tb->phys_hash_next;
tb->phys_hash_next = tcg_ctx->tb_ctx.tb_phys_hash[h];
tcg_ctx->tb_ctx.tb_phys_hash[h] = tb;
}
/* we add the TB in the virtual pc hash table */
cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;
return tb;
}
static inline TranslationBlock *tb_find_fast(CPUState *cpu,
TranslationBlock **last_tb,
int tb_exit)
{
CPUArchState *env = (CPUArchState *)cpu->env_ptr;
TranslationBlock *tb;
target_ulong cs_base, pc;
uint32_t flags;
/* we record a subset of the CPU state. It will
always be the same before a given translated block
is executed. */
cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
// Unicorn: commented out
//tb_lock();
tb = cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];
if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
tb->flags != flags)) {
tb = tb_find_slow(cpu, pc, cs_base, flags); // qq
}
if (cpu->tb_flushed) {
/* Ensure that no TB jump will be modified as the
* translation buffer has been flushed.
*/
*last_tb = NULL;
cpu->tb_flushed = false;
}
/* See if we can patch the calling TB. */
if (*last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
tb_add_jump(*last_tb, tb_exit, tb);
}
// Unicorn: commented out
//tb_unlock();
return tb;
}
static inline bool cpu_handle_halt(CPUState *cpu)
{
if (cpu->halted) {
if (!cpu_has_work(cpu)) {
return true;
}
cpu->halted = 0;
}
return false;
}
static inline void cpu_handle_debug_exception(CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
CPUWatchpoint *wp;
if (!cpu->watchpoint_hit) {
QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
wp->flags &= ~BP_WATCHPOINT_HIT;
}
}
cc->debug_excp_handler(cpu);
}
static inline bool cpu_handle_exception(struct uc_struct *uc, CPUState *cpu, int *ret)
{
struct hook *hook;
if (cpu->exception_index >= 0) {
if (uc->stop_interrupt && uc->stop_interrupt(cpu->exception_index)) {
cpu->halted = 1;
uc->invalid_error = UC_ERR_INSN_INVALID;
*ret = EXCP_HLT;
return true;
}
if (cpu->exception_index >= EXCP_INTERRUPT) {
/* exit request from the cpu execution loop */
*ret = cpu->exception_index;
if (*ret == EXCP_DEBUG) {
cpu_handle_debug_exception(cpu);
}
cpu->exception_index = -1;
return true;
} else {
#if defined(CONFIG_USER_ONLY)
/* if user mode only, we simulate a fake exception
which will be handled outside the cpu execution
loop */
#if defined(TARGET_I386)
CPUClass *cc = CPU_GET_CLASS(cpu);
cc->do_interrupt(cpu);
#endif
*ret = cpu->exception_index;
cpu->exception_index = -1;
return true;
#else
bool catched = false;
// Unicorn: call registered interrupt callbacks
HOOK_FOREACH_VAR_DECLARE;
HOOK_FOREACH(uc, hook, UC_HOOK_INTR) {
((uc_cb_hookintr_t)hook->callback)(uc, cpu->exception_index, hook->user_data);
catched = true;
}
// Unicorn: If un-catched interrupt, stop executions.
if (!catched) {
cpu->halted = 1;
uc->invalid_error = UC_ERR_EXCEPTION;
*ret = EXCP_HLT;
return true;
}
cpu->exception_index = -1;
#endif
}
}
return false;
}
static inline void cpu_handle_interrupt(CPUState *cpu,
TranslationBlock **last_tb)
{
CPUClass *cc = CPU_GET_CLASS(cpu->uc, cpu);
int interrupt_request = cpu->interrupt_request;
if (unlikely(interrupt_request)) {
if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
/* Mask out external interrupts for this step. */
interrupt_request &= ~CPU_INTERRUPT_SSTEP_MASK;
}
if (interrupt_request & CPU_INTERRUPT_DEBUG) {
cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
cpu->exception_index = EXCP_DEBUG;
cpu_loop_exit(cpu);
}
if (interrupt_request & CPU_INTERRUPT_HALT) {
cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
cpu->halted = 1;
cpu->exception_index = EXCP_HLT;
cpu_loop_exit(cpu);
}
#if defined(TARGET_I386)
else if (interrupt_request & CPU_INTERRUPT_INIT) {
X86CPU *x86_cpu = X86_CPU(cpu->uc, cpu);
CPUArchState *env = &x86_cpu->env;
cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0);
do_cpu_init(x86_cpu);
cpu->exception_index = EXCP_HALTED;
cpu_loop_exit(cpu);
}
#else
else if (interrupt_request & CPU_INTERRUPT_RESET) {
cpu_reset(cpu);
}
#endif
else {
/* The target hook has 3 exit conditions:
False when the interrupt isn't processed,
True when it is, and we should restart on a new TB,
and via longjmp via cpu_loop_exit. */
if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
*last_tb = NULL;
}
/* The target hook may have updated the 'cpu->interrupt_request';
* reload the 'interrupt_request' value */
interrupt_request = cpu->interrupt_request;
}
if (interrupt_request & CPU_INTERRUPT_EXITTB) {
cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB;
/* ensure that no TB jump will be modified as
the program flow was changed */
*last_tb = NULL;
}
}
if (unlikely(cpu->exit_request)) {
cpu->exit_request = 0;
cpu->exception_index = EXCP_INTERRUPT;
cpu_loop_exit(cpu);
}
}
static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
TranslationBlock **last_tb, int *tb_exit)
{
uintptr_t ret;
if (unlikely(cpu->exit_request)) {
return;
}
/* execute the generated code */
ret = cpu_tb_exec(cpu, tb);
*last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
*tb_exit = ret & TB_EXIT_MASK;
switch (*tb_exit) {
case TB_EXIT_REQUESTED:
/* Something asked us to stop executing
* chained TBs; just continue round the main
* loop. Whatever requested the exit will also
* have set something else (eg exit_request or
* interrupt_request) which we will handle
* next time around the loop. But we need to
* ensure the tcg_exit_req read in generated code
* comes before the next read of cpu->exit_request
* or cpu->interrupt_request.
*/
smp_rmb();
*last_tb = NULL;
break;
default:
break;
}
}
/* main execution loop */
int cpu_exec(struct uc_struct *uc, CPUState *cpu)
{
CPUArchState *env = cpu->env_ptr;
CPUClass *cc = CPU_GET_CLASS(uc, cpu);
int ret;
if (cpu_handle_halt(cpu)) {
return EXCP_HALTED;
}
uc->current_cpu = cpu;
atomic_mb_set(&uc->tcg_current_cpu, cpu);
if (unlikely(atomic_mb_read(&uc->exit_request))) {
cpu->exit_request = 1;
}
cc->cpu_exec_enter(cpu);
cpu->exception_index = -1;
env->invalid_error = UC_ERR_OK;
for(;;) {
TranslationBlock *tb, *last_tb;
int tb_exit = 0;
/* prepare setjmp context for exception handling */
if (sigsetjmp(cpu->jmp_env, 0) == 0) {
if (uc->stop_request || uc->invalid_error) {
break;
}
/* if an exception is pending, we execute it here */
if (cpu_handle_exception(uc, cpu, &ret)) {
break;
}
last_tb = NULL; /* forget the last executed TB after exception */
cpu->tb_flushed = false; /* reset before first TB lookup */
for(;;) {
cpu_handle_interrupt(cpu, &last_tb);
tb = tb_find_fast(cpu, &last_tb, tb_exit);
if (!tb) { // invalid TB due to invalid code?
uc->invalid_error = UC_ERR_FETCH_UNMAPPED;
ret = EXCP_HLT;
break;
}
cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit);
} /* for(;;) */
} else {
#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
/* Some compilers wrongly smash all local variables after
* siglongjmp. There were bug reports for gcc 4.5.0 and clang.
* Reload essential local variables here for those compilers.
* Newer versions of gcc would complain about this code (-Wclobbered). */
cpu = uc->current_cpu;
env = cpu->env_ptr;
cc = CPU_GET_CLASS(uc, cpu);
#else /* buggy compiler */
/* Assert that the compiler does not smash local variables. */
g_assert(cpu == current_cpu);
g_assert(cc == CPU_GET_CLASS(cpu));
#endif /* buggy compiler */
cpu->can_do_io = 1;
}
} /* for(;;) */
cc->cpu_exec_exit(cpu);
// Unicorn: flush JIT cache to because emulation might stop in
// the middle of translation, thus generate incomplete code.
// TODO: optimize this for better performance
tb_flush(cpu);
/* fail safe : never use current_cpu outside cpu_exec() */
uc->current_cpu = NULL;
/* Does not need atomic_mb_set because a spurious wakeup is okay. */
atomic_set(&uc->tcg_current_cpu, NULL);
return ret;
}