unicorn/qemu/accel/tcg/cpu-exec.c

619 lines
19 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 2.1 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/>.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "hw/core/cpu.h"
#include "exec/exec-all.h"
#include "tcg/tcg.h"
#include "qemu/atomic.h"
#include "qemu/timer.h"
#include "exec/tb-hash.h"
#include "exec/tb-lookup.h"
#include "sysemu/cpus.h"
#include "uc_priv.h"
/* -icount align implementation. */
typedef struct SyncClocks {
int64_t diff_clk;
int64_t last_cpu_icount;
int64_t realtime_clock;
} SyncClocks;
/* Allow the guest to have a max 3ms advance.
* The difference between the 2 clocks could therefore
* oscillate around 0.
*/
#define VM_CLOCK_ADVANCE 3000000
#define THRESHOLD_REDUCE 1.5
#define MAX_DELAY_PRINT_RATE 2000000000LL
#define MAX_NB_PRINTS 100
/* 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;
uintptr_t ret;
TranslationBlock *last_tb;
int tb_exit;
uint8_t *tb_ptr = itb->tc.ptr;
UC_TRACE_START(UC_TRACE_TB_EXEC);
tb_exec_lock(cpu->uc->tcg_ctx);
ret = tcg_qemu_tb_exec(env, tb_ptr);
tb_exec_unlock(cpu->uc->tcg_ctx);
UC_TRACE_END(UC_TRACE_TB_EXEC, "[uc] exec tb 0x%" PRIx64 ": ", itb->pc);
cpu->can_do_io = 1;
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(cpu);
if (!HOOK_EXISTS(env->uc, UC_HOOK_CODE)) {
// We should sync pc for R/W error.
switch (env->uc->invalid_error) {
case UC_ERR_WRITE_PROT:
case UC_ERR_READ_PROT:
case UC_ERR_FETCH_PROT:
case UC_ERR_WRITE_UNMAPPED:
case UC_ERR_READ_UNMAPPED:
case UC_ERR_FETCH_UNMAPPED:
case UC_ERR_WRITE_UNALIGNED:
case UC_ERR_READ_UNALIGNED:
case UC_ERR_FETCH_UNALIGNED:
break;
default:
// If we receive a quit request, users has sync-ed PC themselves.
if (!cpu->uc->quit_request) {
if (cc->synchronize_from_tb) {
cc->synchronize_from_tb(cpu, last_tb);
} else {
assert(cc->set_pc);
cc->set_pc(cpu, last_tb->pc);
}
}
}
}
cpu->tcg_exit_req = 0;
}
return ret;
}
/* Execute the code without caching the generated code. An interpreter
could be used if available. */
static void cpu_exec_nocache(CPUState *cpu, int max_cycles,
TranslationBlock *orig_tb, bool ignore_icount)
{
TranslationBlock *tb;
uint32_t cflags = curr_cflags() | CF_NOCACHE;
if (ignore_icount) {
cflags &= ~CF_USE_ICOUNT;
}
/* Should never happen.
We only end up here when an existing TB is too long. */
cflags |= MIN(max_cycles, CF_COUNT_MASK);
mmap_lock();
tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base,
orig_tb->flags, cflags);
tb->orig_tb = orig_tb;
mmap_unlock();
/* execute the generated code */
cpu_tb_exec(cpu, tb);
mmap_lock();
tb_phys_invalidate(cpu->uc->tcg_ctx, tb, -1);
mmap_unlock();
tcg_tb_remove(cpu->uc->tcg_ctx, tb);
}
struct tb_desc {
target_ulong pc;
target_ulong cs_base;
CPUArchState *env;
tb_page_addr_t phys_page1;
uint32_t flags;
uint32_t cf_mask;
uint32_t trace_vcpu_dstate;
};
static bool tb_lookup_cmp(struct uc_struct *uc, const void *p, const void *d)
{
const TranslationBlock *tb = p;
const struct tb_desc *desc = d;
if (tb->pc == desc->pc &&
tb->page_addr[0] == desc->phys_page1 &&
tb->cs_base == desc->cs_base &&
tb->flags == desc->flags &&
tb->trace_vcpu_dstate == desc->trace_vcpu_dstate &&
(tb_cflags(tb) & (CF_HASH_MASK | CF_INVALID)) == desc->cf_mask) {
/* check next page if needed */
if (tb->page_addr[1] == -1) {
return true;
} else {
tb_page_addr_t phys_page2;
target_ulong virt_page2;
virt_page2 = (desc->pc & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
phys_page2 = get_page_addr_code(desc->env, virt_page2);
if (tb->page_addr[1] == phys_page2) {
return true;
}
}
}
return false;
}
TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc,
target_ulong cs_base, uint32_t flags,
uint32_t cf_mask)
{
struct uc_struct *uc = cpu->uc;
tb_page_addr_t phys_pc;
struct tb_desc desc;
uint32_t h;
desc.env = (CPUArchState *)cpu->env_ptr;
desc.cs_base = cs_base;
desc.flags = flags;
desc.cf_mask = cf_mask;
desc.trace_vcpu_dstate = *cpu->trace_dstate;
desc.pc = pc;
phys_pc = get_page_addr_code(desc.env, pc);
if (phys_pc == -1) {
return NULL;
}
desc.phys_page1 = phys_pc & TARGET_PAGE_MASK;
h = tb_hash_func(phys_pc, pc, flags, cf_mask, *cpu->trace_dstate);
return qht_lookup_custom(uc, &cpu->uc->tcg_ctx->tb_ctx.htable, &desc, h, tb_lookup_cmp);
}
void tb_set_jmp_target(TranslationBlock *tb, int n, uintptr_t addr)
{
if (TCG_TARGET_HAS_direct_jump) {
uintptr_t offset = tb->jmp_target_arg[n];
uintptr_t tc_ptr = (uintptr_t)tb->tc.ptr;
tb_target_set_jmp_target(tc_ptr, tc_ptr + offset, addr);
} else {
tb->jmp_target_arg[n] = addr;
}
}
static inline void tb_add_jump(TranslationBlock *tb, int n,
TranslationBlock *tb_next)
{
uintptr_t old;
assert(n < ARRAY_SIZE(tb->jmp_list_next));
/* make sure the destination TB is valid */
if (tb_next->cflags & CF_INVALID) {
goto out_unlock_next;
}
/* Atomically claim the jump destination slot only if it was NULL */
#ifdef _MSC_VER
old = atomic_cmpxchg((long *)&tb->jmp_dest[n], (uintptr_t)NULL, (uintptr_t)tb_next);
#else
old = atomic_cmpxchg(&tb->jmp_dest[n], (uintptr_t)NULL, (uintptr_t)tb_next);
#endif
if (old) {
goto out_unlock_next;
}
/* patch the native jump address */
tb_set_jmp_target(tb, n, (uintptr_t)tb_next->tc.ptr);
/* add in TB jmp list */
tb->jmp_list_next[n] = tb_next->jmp_list_head;
tb_next->jmp_list_head = (uintptr_t)tb | n;
return;
out_unlock_next:
return;
}
static inline TranslationBlock *tb_find(CPUState *cpu,
TranslationBlock *last_tb,
int tb_exit, uint32_t cf_mask)
{
TranslationBlock *tb;
target_ulong cs_base, pc;
uint32_t flags;
uc_tb cur_tb, prev_tb;
uc_engine *uc = cpu->uc;
struct list_item *cur;
struct hook *hook;
tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags, cf_mask);
if (tb == NULL) {
mmap_lock();
tb = tb_gen_code(cpu, pc, cs_base, flags, cf_mask);
mmap_unlock();
/* We add the TB in the virtual pc hash table for the fast lookup */
cpu->tb_jmp_cache[tb_jmp_cache_hash_func(cpu->uc, pc)] = tb;
if (uc->last_tb) {
UC_TB_COPY(&cur_tb, tb);
UC_TB_COPY(&prev_tb, uc->last_tb);
for (cur = uc->hook[UC_HOOK_EDGE_GENERATED_IDX].head;
cur != NULL && (hook = (struct hook *)cur->data); cur = cur->next) {
if (hook->to_delete) {
continue;
}
if (HOOK_BOUND_CHECK(hook, (uint64_t)tb->pc)) {
((uc_hook_edge_gen_t)hook->callback)(uc, &cur_tb, &prev_tb, hook->user_data);
}
}
}
}
/* We don't take care of direct jumps when address mapping changes in
* system emulation. So it's not safe to make a direct jump to a TB
* spanning two pages because the mapping for the second page can change.
*/
if (tb->page_addr[1] != -1) {
last_tb = NULL;
}
/* See if we can patch the calling TB. */
if (last_tb) {
tb_add_jump(last_tb, tb_exit, tb);
}
return tb;
}
static inline bool cpu_handle_halt(CPUState *cpu)
{
if (cpu->halted) {
#if 0
#if defined(TARGET_I386)
if ((cpu->interrupt_request & CPU_INTERRUPT_POLL)
&& replay_interrupt()) {
X86CPU *x86_cpu = X86_CPU(cpu);
apic_poll_irq(x86_cpu->apic_state);
cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
}
#endif
#endif
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);
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(CPUState *cpu, int *ret)
{
bool catched = false;
struct uc_struct *uc = cpu->uc;
struct hook *hook;
// printf(">> exception index = %u\n", cpu->exception_index); qq
if (cpu->uc->stop_interrupt && cpu->uc->stop_interrupt(cpu->uc, cpu->exception_index)) {
// Unicorn: call registered invalid instruction callbacks
catched = false;
HOOK_FOREACH_VAR_DECLARE;
HOOK_FOREACH(uc, hook, UC_HOOK_INSN_INVALID) {
if (hook->to_delete) {
continue;
}
catched = ((uc_cb_hookinsn_invalid_t)hook->callback)(uc, hook->user_data);
if (catched) {
break;
}
}
if (!catched) {
uc->invalid_error = UC_ERR_INSN_INVALID;
}
// we want to stop emulation
*ret = EXCP_HLT;
return true;
}
if (cpu->exception_index < 0) {
return false;
}
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(TARGET_X86_64)
CPUArchState *env = cpu->env_ptr;
if (env->exception_is_int) {
// point EIP to the next instruction after INT
env->eip = env->exception_next_eip;
}
#endif
#if defined(TARGET_MIPS) || defined(TARGET_MIPS64)
// Unicorn: Imported from https://github.com/unicorn-engine/unicorn/pull/1098
CPUMIPSState *env = &(MIPS_CPU(cpu)->env);
env->active_tc.PC = uc->next_pc;
#endif
#if defined(TARGET_RISCV)
CPURISCVState *env = &(RISCV_CPU(uc->cpu)->env);
env->pc += 4;
#endif
#if defined(TARGET_PPC)
CPUPPCState *env = &(POWERPC_CPU(uc->cpu)->env);
env->nip += 4;
#endif
// Unicorn: call registered interrupt callbacks
catched = false;
HOOK_FOREACH_VAR_DECLARE;
HOOK_FOREACH(uc, hook, UC_HOOK_INTR) {
if (hook->to_delete) {
continue;
}
((uc_cb_hookintr_t)hook->callback)(uc, cpu->exception_index, hook->user_data);
catched = true;
}
// Unicorn: If un-catched interrupt, stop executions.
if (!catched) {
// printf("AAAAAAAAAAAA\n"); qq
uc->invalid_error = UC_ERR_EXCEPTION;
cpu->halted = 1;
*ret = EXCP_HLT;
return true;
}
cpu->exception_index = -1;
}
*ret = EXCP_INTERRUPT;
return false;
}
static inline bool cpu_handle_interrupt(CPUState *cpu,
TranslationBlock **last_tb)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
/* Clear the interrupt flag now since we're processing
* cpu->interrupt_request and cpu->exit_request.
* Ensure zeroing happens before reading cpu->exit_request or
* cpu->interrupt_request (see also smp_wmb in cpu_exit())
*/
cpu_neg(cpu)->icount_decr.u16.high = 0;
if (unlikely(cpu->interrupt_request)) {
int interrupt_request;
interrupt_request = cpu->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;
return true;
}
#if defined(TARGET_I386)
else if (interrupt_request & CPU_INTERRUPT_INIT) {
X86CPU *x86_cpu = X86_CPU(cpu);
CPUArchState *env = &x86_cpu->env;
//replay_interrupt();
cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 0);
do_cpu_init(x86_cpu);
cpu->exception_index = EXCP_HALTED;
return true;
}
#else
else if (interrupt_request & CPU_INTERRUPT_RESET) {
//replay_interrupt();
cpu_reset(cpu);
return true;
}
#endif
/* 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. */
else {
if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
//replay_interrupt();
cpu->exception_index = -1;
*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;
}
}
/* Finally, check if we need to exit to the main loop. */
if (unlikely(cpu->exit_request)) {
cpu->exit_request = 0;
if (cpu->exception_index == -1) {
cpu->exception_index = EXCP_INTERRUPT;
}
return true;
}
return false;
}
static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
TranslationBlock **last_tb, int *tb_exit)
{
uintptr_t ret;
int32_t insns_left;
// trace_exec_tb(tb, tb->pc);
ret = cpu_tb_exec(cpu, tb);
cpu->uc->last_tb = tb; // Trace the last tb we executed.
tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK);
*tb_exit = ret & TB_EXIT_MASK;
if (*tb_exit != TB_EXIT_REQUESTED) {
*last_tb = tb;
return;
}
*last_tb = NULL;
insns_left = cpu_neg(cpu)->icount_decr.u32;
if (insns_left < 0) {
/* 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 will be handled by
* cpu_handle_interrupt. cpu_handle_interrupt will also
* clear cpu->icount_decr.u16.high.
*/
return;
}
/* Instruction counter expired. */
/* Refill decrementer and continue execution. */
insns_left = MIN(0xffff, cpu->icount_budget);
cpu_neg(cpu)->icount_decr.u16.low = insns_left;
cpu->icount_extra = cpu->icount_budget - insns_left;
if (!cpu->icount_extra) {
/* Execute any remaining instructions, then let the main loop
* handle the next event.
*/
if (insns_left > 0) {
cpu_exec_nocache(cpu, insns_left, tb, false);
}
}
}
/* main execution loop */
int cpu_exec(struct uc_struct *uc, CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
int ret;
// SyncClocks sc = { 0 };
if (cpu_handle_halt(cpu)) {
return EXCP_HALTED;
}
// rcu_read_lock();
cc->cpu_exec_enter(cpu);
/* Calculate difference between guest clock and host clock.
* This delay includes the delay of the last cycle, so
* what we have to do is sleep until it is 0. As for the
* advance/delay we gain here, we try to fix it next time.
*/
// init_delay_params(&sc, cpu);
// Unicorn: We would like to support nested uc_emu_start calls.
/* prepare setjmp context for exception handling */
// if (sigsetjmp(cpu->jmp_env, 0) != 0) {
if (sigsetjmp(uc->jmp_bufs[uc->nested_level - 1], 0) != 0) {
#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). */
cc = CPU_GET_CLASS(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 */
assert_no_pages_locked();
}
/* if an exception is pending, we execute it here */
while (!cpu_handle_exception(cpu, &ret)) {
TranslationBlock *last_tb = NULL;
int tb_exit = 0;
while (!cpu_handle_interrupt(cpu, &last_tb)) {
uint32_t cflags = cpu->cflags_next_tb;
TranslationBlock *tb;
/* When requested, use an exact setting for cflags for the next
execution. This is used for icount, precise smc, and stop-
after-access watchpoints. Since this request should never
have CF_INVALID set, -1 is a convenient invalid value that
does not require tcg headers for cpu_common_reset. */
if (cflags == -1) {
cflags = curr_cflags();
} else {
cpu->cflags_next_tb = -1;
}
tb = tb_find(cpu, last_tb, tb_exit, cflags);
if (unlikely(cpu->exit_request)) {
continue;
}
cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit);
/* Try to align the host and virtual clocks
if the guest is in advance */
// align_clocks(&sc, cpu);
}
}
// Unicorn: Clear any TCG exit flag that might have been left set by exit requests
uc->cpu->tcg_exit_req = 0;
cc->cpu_exec_exit(cpu);
// rcu_read_unlock();
return ret;
}