mirror of https://github.com/proxmox/mirror_qemu
556 lines
19 KiB
C
556 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 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 "config.h"
|
|
#include "cpu.h"
|
|
#include "trace.h"
|
|
#include "disas/disas.h"
|
|
#include "tcg.h"
|
|
#include "qemu/atomic.h"
|
|
#include "sysemu/qtest.h"
|
|
#include "qemu/timer.h"
|
|
|
|
/* -icount align implementation. */
|
|
|
|
typedef struct SyncClocks {
|
|
int64_t diff_clk;
|
|
int64_t last_cpu_icount;
|
|
int64_t realtime_clock;
|
|
} SyncClocks;
|
|
|
|
#if !defined(CONFIG_USER_ONLY)
|
|
/* 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
|
|
|
|
static void align_clocks(SyncClocks *sc, const CPUState *cpu)
|
|
{
|
|
int64_t cpu_icount;
|
|
|
|
if (!icount_align_option) {
|
|
return;
|
|
}
|
|
|
|
cpu_icount = cpu->icount_extra + cpu->icount_decr.u16.low;
|
|
sc->diff_clk += cpu_icount_to_ns(sc->last_cpu_icount - cpu_icount);
|
|
sc->last_cpu_icount = cpu_icount;
|
|
|
|
if (sc->diff_clk > VM_CLOCK_ADVANCE) {
|
|
#ifndef _WIN32
|
|
struct timespec sleep_delay, rem_delay;
|
|
sleep_delay.tv_sec = sc->diff_clk / 1000000000LL;
|
|
sleep_delay.tv_nsec = sc->diff_clk % 1000000000LL;
|
|
if (nanosleep(&sleep_delay, &rem_delay) < 0) {
|
|
sc->diff_clk = rem_delay.tv_sec * 1000000000LL + rem_delay.tv_nsec;
|
|
} else {
|
|
sc->diff_clk = 0;
|
|
}
|
|
#else
|
|
Sleep(sc->diff_clk / SCALE_MS);
|
|
sc->diff_clk = 0;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
static void print_delay(const SyncClocks *sc)
|
|
{
|
|
static float threshold_delay;
|
|
static int64_t last_realtime_clock;
|
|
static int nb_prints;
|
|
|
|
if (icount_align_option &&
|
|
sc->realtime_clock - last_realtime_clock >= MAX_DELAY_PRINT_RATE &&
|
|
nb_prints < MAX_NB_PRINTS) {
|
|
if ((-sc->diff_clk / (float)1000000000LL > threshold_delay) ||
|
|
(-sc->diff_clk / (float)1000000000LL <
|
|
(threshold_delay - THRESHOLD_REDUCE))) {
|
|
threshold_delay = (-sc->diff_clk / 1000000000LL) + 1;
|
|
printf("Warning: The guest is now late by %.1f to %.1f seconds\n",
|
|
threshold_delay - 1,
|
|
threshold_delay);
|
|
nb_prints++;
|
|
last_realtime_clock = sc->realtime_clock;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void init_delay_params(SyncClocks *sc,
|
|
const CPUState *cpu)
|
|
{
|
|
if (!icount_align_option) {
|
|
return;
|
|
}
|
|
sc->realtime_clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT);
|
|
sc->diff_clk = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - sc->realtime_clock;
|
|
sc->last_cpu_icount = cpu->icount_extra + cpu->icount_decr.u16.low;
|
|
if (sc->diff_clk < max_delay) {
|
|
max_delay = sc->diff_clk;
|
|
}
|
|
if (sc->diff_clk > max_advance) {
|
|
max_advance = sc->diff_clk;
|
|
}
|
|
|
|
/* Print every 2s max if the guest is late. We limit the number
|
|
of printed messages to NB_PRINT_MAX(currently 100) */
|
|
print_delay(sc);
|
|
}
|
|
#else
|
|
static void align_clocks(SyncClocks *sc, const CPUState *cpu)
|
|
{
|
|
}
|
|
|
|
static void init_delay_params(SyncClocks *sc, const CPUState *cpu)
|
|
{
|
|
}
|
|
#endif /* CONFIG USER ONLY */
|
|
|
|
void cpu_loop_exit(CPUState *cpu)
|
|
{
|
|
cpu->current_tb = NULL;
|
|
siglongjmp(cpu->jmp_env, 1);
|
|
}
|
|
|
|
/* exit the current TB from a signal handler. The host registers are
|
|
restored in a state compatible with the CPU emulator
|
|
*/
|
|
#if defined(CONFIG_SOFTMMU)
|
|
void cpu_resume_from_signal(CPUState *cpu, void *puc)
|
|
{
|
|
/* XXX: restore cpu registers saved in host registers */
|
|
|
|
cpu->exception_index = -1;
|
|
siglongjmp(cpu->jmp_env, 1);
|
|
}
|
|
#endif
|
|
|
|
/* Execute a TB, and fix up the CPU state afterwards if necessary */
|
|
static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr)
|
|
{
|
|
CPUArchState *env = cpu->env_ptr;
|
|
uintptr_t next_tb;
|
|
|
|
#if defined(DEBUG_DISAS)
|
|
if (qemu_loglevel_mask(CPU_LOG_TB_CPU)) {
|
|
#if defined(TARGET_I386)
|
|
log_cpu_state(cpu, CPU_DUMP_CCOP);
|
|
#elif defined(TARGET_M68K)
|
|
/* ??? Should not modify env state for dumping. */
|
|
cpu_m68k_flush_flags(env, env->cc_op);
|
|
env->cc_op = CC_OP_FLAGS;
|
|
env->sr = (env->sr & 0xffe0) | env->cc_dest | (env->cc_x << 4);
|
|
log_cpu_state(cpu, 0);
|
|
#else
|
|
log_cpu_state(cpu, 0);
|
|
#endif
|
|
}
|
|
#endif /* DEBUG_DISAS */
|
|
|
|
cpu->can_do_io = 0;
|
|
next_tb = tcg_qemu_tb_exec(env, tb_ptr);
|
|
cpu->can_do_io = 1;
|
|
trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK),
|
|
next_tb & TB_EXIT_MASK);
|
|
|
|
if ((next_tb & TB_EXIT_MASK) > 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);
|
|
TranslationBlock *tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK);
|
|
if (cc->synchronize_from_tb) {
|
|
cc->synchronize_from_tb(cpu, tb);
|
|
} else {
|
|
assert(cc->set_pc);
|
|
cc->set_pc(cpu, tb->pc);
|
|
}
|
|
}
|
|
if ((next_tb & TB_EXIT_MASK) == 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 next_tb;
|
|
}
|
|
|
|
/* Execute the code without caching the generated code. An interpreter
|
|
could be used if available. */
|
|
static void cpu_exec_nocache(CPUArchState *env, int max_cycles,
|
|
TranslationBlock *orig_tb)
|
|
{
|
|
CPUState *cpu = ENV_GET_CPU(env);
|
|
TranslationBlock *tb;
|
|
target_ulong pc = orig_tb->pc;
|
|
target_ulong cs_base = orig_tb->cs_base;
|
|
uint64_t flags = orig_tb->flags;
|
|
|
|
/* Should never happen.
|
|
We only end up here when an existing TB is too long. */
|
|
if (max_cycles > CF_COUNT_MASK)
|
|
max_cycles = CF_COUNT_MASK;
|
|
|
|
/* tb_gen_code can flush our orig_tb, invalidate it now */
|
|
tb_phys_invalidate(orig_tb, -1);
|
|
tb = tb_gen_code(cpu, pc, cs_base, flags,
|
|
max_cycles | CF_NOCACHE);
|
|
cpu->current_tb = tb;
|
|
/* execute the generated code */
|
|
trace_exec_tb_nocache(tb, tb->pc);
|
|
cpu_tb_exec(cpu, tb->tc_ptr);
|
|
cpu->current_tb = NULL;
|
|
tb_phys_invalidate(tb, -1);
|
|
tb_free(tb);
|
|
}
|
|
|
|
static TranslationBlock *tb_find_slow(CPUArchState *env,
|
|
target_ulong pc,
|
|
target_ulong cs_base,
|
|
uint64_t flags)
|
|
{
|
|
CPUState *cpu = ENV_GET_CPU(env);
|
|
TranslationBlock *tb, **ptb1;
|
|
unsigned int h;
|
|
tb_page_addr_t phys_pc, phys_page1;
|
|
target_ulong virt_page2;
|
|
|
|
tcg_ctx.tb_ctx.tb_invalidated_flag = 0;
|
|
|
|
/* find translated block using physical mappings */
|
|
phys_pc = get_page_addr_code(env, pc);
|
|
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, flags, 0);
|
|
|
|
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(CPUArchState *env)
|
|
{
|
|
CPUState *cpu = ENV_GET_CPU(env);
|
|
TranslationBlock *tb;
|
|
target_ulong cs_base, pc;
|
|
int 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);
|
|
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(env, pc, cs_base, flags);
|
|
}
|
|
return tb;
|
|
}
|
|
|
|
static void cpu_handle_debug_exception(CPUArchState *env)
|
|
{
|
|
CPUState *cpu = ENV_GET_CPU(env);
|
|
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);
|
|
}
|
|
|
|
/* main execution loop */
|
|
|
|
volatile sig_atomic_t exit_request;
|
|
|
|
int cpu_exec(CPUArchState *env)
|
|
{
|
|
CPUState *cpu = ENV_GET_CPU(env);
|
|
CPUClass *cc = CPU_GET_CLASS(cpu);
|
|
#ifdef TARGET_I386
|
|
X86CPU *x86_cpu = X86_CPU(cpu);
|
|
#endif
|
|
int ret, interrupt_request;
|
|
TranslationBlock *tb;
|
|
uint8_t *tc_ptr;
|
|
uintptr_t next_tb;
|
|
SyncClocks sc;
|
|
|
|
/* This must be volatile so it is not trashed by longjmp() */
|
|
volatile bool have_tb_lock = false;
|
|
|
|
if (cpu->halted) {
|
|
if (!cpu_has_work(cpu)) {
|
|
return EXCP_HALTED;
|
|
}
|
|
|
|
cpu->halted = 0;
|
|
}
|
|
|
|
current_cpu = cpu;
|
|
|
|
/* As long as current_cpu is null, up to the assignment just above,
|
|
* requests by other threads to exit the execution loop are expected to
|
|
* be issued using the exit_request global. We must make sure that our
|
|
* evaluation of the global value is performed past the current_cpu
|
|
* value transition point, which requires a memory barrier as well as
|
|
* an instruction scheduling constraint on modern architectures. */
|
|
smp_mb();
|
|
|
|
if (unlikely(exit_request)) {
|
|
cpu->exit_request = 1;
|
|
}
|
|
|
|
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);
|
|
|
|
/* prepare setjmp context for exception handling */
|
|
for(;;) {
|
|
if (sigsetjmp(cpu->jmp_env, 0) == 0) {
|
|
/* if an exception is pending, we execute it here */
|
|
if (cpu->exception_index >= 0) {
|
|
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(env);
|
|
}
|
|
cpu->exception_index = -1;
|
|
break;
|
|
} 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)
|
|
cc->do_interrupt(cpu);
|
|
#endif
|
|
ret = cpu->exception_index;
|
|
cpu->exception_index = -1;
|
|
break;
|
|
#else
|
|
cc->do_interrupt(cpu);
|
|
cpu->exception_index = -1;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
next_tb = 0; /* force lookup of first TB */
|
|
for(;;) {
|
|
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)
|
|
if (interrupt_request & CPU_INTERRUPT_INIT) {
|
|
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
|
|
if (interrupt_request & CPU_INTERRUPT_RESET) {
|
|
cpu_reset(cpu);
|
|
}
|
|
#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. */
|
|
if (cc->cpu_exec_interrupt(cpu, interrupt_request)) {
|
|
next_tb = 0;
|
|
}
|
|
/* Don't use the cached interrupt_request value,
|
|
do_interrupt may have updated the EXITTB flag. */
|
|
if (cpu->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 */
|
|
next_tb = 0;
|
|
}
|
|
}
|
|
if (unlikely(cpu->exit_request)) {
|
|
cpu->exit_request = 0;
|
|
cpu->exception_index = EXCP_INTERRUPT;
|
|
cpu_loop_exit(cpu);
|
|
}
|
|
spin_lock(&tcg_ctx.tb_ctx.tb_lock);
|
|
have_tb_lock = true;
|
|
tb = tb_find_fast(env);
|
|
/* Note: we do it here to avoid a gcc bug on Mac OS X when
|
|
doing it in tb_find_slow */
|
|
if (tcg_ctx.tb_ctx.tb_invalidated_flag) {
|
|
/* as some TB could have been invalidated because
|
|
of memory exceptions while generating the code, we
|
|
must recompute the hash index here */
|
|
next_tb = 0;
|
|
tcg_ctx.tb_ctx.tb_invalidated_flag = 0;
|
|
}
|
|
if (qemu_loglevel_mask(CPU_LOG_EXEC)) {
|
|
qemu_log("Trace %p [" TARGET_FMT_lx "] %s\n",
|
|
tb->tc_ptr, tb->pc, lookup_symbol(tb->pc));
|
|
}
|
|
/* see if we can patch the calling TB. When the TB
|
|
spans two pages, we cannot safely do a direct
|
|
jump. */
|
|
if (next_tb != 0 && tb->page_addr[1] == -1) {
|
|
tb_add_jump((TranslationBlock *)(next_tb & ~TB_EXIT_MASK),
|
|
next_tb & TB_EXIT_MASK, tb);
|
|
}
|
|
have_tb_lock = false;
|
|
spin_unlock(&tcg_ctx.tb_ctx.tb_lock);
|
|
|
|
/* cpu_interrupt might be called while translating the
|
|
TB, but before it is linked into a potentially
|
|
infinite loop and becomes env->current_tb. Avoid
|
|
starting execution if there is a pending interrupt. */
|
|
cpu->current_tb = tb;
|
|
barrier();
|
|
if (likely(!cpu->exit_request)) {
|
|
trace_exec_tb(tb, tb->pc);
|
|
tc_ptr = tb->tc_ptr;
|
|
/* execute the generated code */
|
|
next_tb = cpu_tb_exec(cpu, tc_ptr);
|
|
switch (next_tb & TB_EXIT_MASK) {
|
|
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.
|
|
*/
|
|
next_tb = 0;
|
|
break;
|
|
case TB_EXIT_ICOUNT_EXPIRED:
|
|
{
|
|
/* Instruction counter expired. */
|
|
int insns_left = cpu->icount_decr.u32;
|
|
if (cpu->icount_extra && insns_left >= 0) {
|
|
/* Refill decrementer and continue execution. */
|
|
cpu->icount_extra += insns_left;
|
|
insns_left = MIN(0xffff, cpu->icount_extra);
|
|
cpu->icount_extra -= insns_left;
|
|
cpu->icount_decr.u16.low = insns_left;
|
|
} else {
|
|
if (insns_left > 0) {
|
|
/* Execute remaining instructions. */
|
|
tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK);
|
|
cpu_exec_nocache(env, insns_left, tb);
|
|
align_clocks(&sc, cpu);
|
|
}
|
|
cpu->exception_index = EXCP_INTERRUPT;
|
|
next_tb = 0;
|
|
cpu_loop_exit(cpu);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
cpu->current_tb = NULL;
|
|
/* Try to align the host and virtual clocks
|
|
if the guest is in advance */
|
|
align_clocks(&sc, cpu);
|
|
/* reset soft MMU for next block (it can currently
|
|
only be set by a memory fault) */
|
|
} /* for(;;) */
|
|
} else {
|
|
/* Reload env after longjmp - the compiler may have smashed all
|
|
* local variables as longjmp is marked 'noreturn'. */
|
|
cpu = current_cpu;
|
|
env = cpu->env_ptr;
|
|
cc = CPU_GET_CLASS(cpu);
|
|
cpu->can_do_io = 1;
|
|
#ifdef TARGET_I386
|
|
x86_cpu = X86_CPU(cpu);
|
|
#endif
|
|
if (have_tb_lock) {
|
|
spin_unlock(&tcg_ctx.tb_ctx.tb_lock);
|
|
have_tb_lock = false;
|
|
}
|
|
}
|
|
} /* for(;;) */
|
|
|
|
cc->cpu_exec_exit(cpu);
|
|
|
|
/* fail safe : never use current_cpu outside cpu_exec() */
|
|
current_cpu = NULL;
|
|
return ret;
|
|
}
|