exec.c

qemu虚拟机代码

#endif /* TARGET_HAS_SMC */
}

/* Allocate a new translation block. Flush the translation buffer if
   too many translation blocks or too much generated code. */
TranslationBlock *tb_alloc(target_ulong pc)
{
    TranslationBlock *tb;

    if (nb_tbs >= CODE_GEN_MAX_BLOCKS || 
        (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE)
        return NULL;
    tb = &tbs[nb_tbs++];
    tb->pc = pc;
    tb->cflags = 0;
    return tb;
}

/* add a new TB and link it to the physical page tables. phys_page2 is
   (-1) to indicate that only one page contains the TB. */
void tb_link_phys(TranslationBlock *tb, 
                  target_ulong phys_pc, target_ulong phys_page2)
{
    unsigned int h;
    TranslationBlock **ptb;

    /* add in the physical hash table */
    h = tb_phys_hash_func(phys_pc);
    ptb = &tb_phys_hash[h];
    tb->phys_hash_next = *ptb;
    *ptb = tb;

    /* add in the page list */
    tb_alloc_page(tb, 0, phys_pc & TARGET_PAGE_MASK);
    if (phys_page2 != -1)
        tb_alloc_page(tb, 1, phys_page2);
    else
        tb->page_addr[1] = -1;

    tb->jmp_first = (TranslationBlock *)((long)tb | 2);
    tb->jmp_next[0] = NULL;
    tb->jmp_next[1] = NULL;
#ifdef USE_CODE_COPY
    tb->cflags &= ~CF_FP_USED;
    if (tb->cflags & CF_TB_FP_USED)
        tb->cflags |= CF_FP_USED;
#endif

    /* init original jump addresses */
    if (tb->tb_next_offset[0] != 0xffff)
        tb_reset_jump(tb, 0);
    if (tb->tb_next_offset[1] != 0xffff)
        tb_reset_jump(tb, 1);

#ifdef DEBUG_TB_CHECK
    tb_page_check();
#endif
}

/* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
   tb[1].tc_ptr. Return NULL if not found */
TranslationBlock *tb_find_pc(unsigned long tc_ptr)
{
    int m_min, m_max, m;
    unsigned long v;
    TranslationBlock *tb;

    if (nb_tbs <= 0)
        return NULL;
    if (tc_ptr < (unsigned long)code_gen_buffer ||
        tc_ptr >= (unsigned long)code_gen_ptr)
        return NULL;
    /* binary search (cf Knuth) */
    m_min = 0;
    m_max = nb_tbs - 1;
    while (m_min <= m_max) {
        m = (m_min + m_max) >> 1;
        tb = &tbs[m];
        v = (unsigned long)tb->tc_ptr;
        if (v == tc_ptr)
            return tb;
        else if (tc_ptr < v) {
            m_max = m - 1;
        } else {
            m_min = m + 1;
        }
    } 
    return &tbs[m_max];
}

static void tb_reset_jump_recursive(TranslationBlock *tb);

static inline void tb_reset_jump_recursive2(TranslationBlock *tb, int n)
{
    TranslationBlock *tb1, *tb_next, **ptb;
    unsigned int n1;

    tb1 = tb->jmp_next[n];
    if (tb1 != NULL) {
        /* find head of list */
        for(;;) {
            n1 = (long)tb1 & 3;
            tb1 = (TranslationBlock *)((long)tb1 & ~3);
            if (n1 == 2)
                break;
            tb1 = tb1->jmp_next[n1];
        }
        /* we are now sure now that tb jumps to tb1 */
        tb_next = tb1;

        /* remove tb from the jmp_first list */
        ptb = &tb_next->jmp_first;
        for(;;) {
            tb1 = *ptb;
            n1 = (long)tb1 & 3;
            tb1 = (TranslationBlock *)((long)tb1 & ~3);
            if (n1 == n && tb1 == tb)
                break;
            ptb = &tb1->jmp_next[n1];
        }
        *ptb = tb->jmp_next[n];
        tb->jmp_next[n] = NULL;
        
        /* suppress the jump to next tb in generated code */
        tb_reset_jump(tb, n);

        /* suppress jumps in the tb on which we could have jumped */
        tb_reset_jump_recursive(tb_next);
    }
}

static void tb_reset_jump_recursive(TranslationBlock *tb)
{
    tb_reset_jump_recursive2(tb, 0);
    tb_reset_jump_recursive2(tb, 1);
}

#if defined(TARGET_HAS_ICE)
static void breakpoint_invalidate(CPUState *env, target_ulong pc)
{
    target_ulong addr, pd;
    ram_addr_t ram_addr;
    PhysPageDesc *p;

    addr = cpu_get_phys_page_debug(env, pc);
    p = phys_page_find(addr >> TARGET_PAGE_BITS);
    if (!p) {
        pd = IO_MEM_UNASSIGNED;
    } else {
        pd = p->phys_offset;
    }
    ram_addr = (pd & TARGET_PAGE_MASK) | (pc & ~TARGET_PAGE_MASK);
    tb_invalidate_phys_page_range(ram_addr, ram_addr + 1, 0);
}
#endif

/* add a breakpoint. EXCP_DEBUG is returned by the CPU loop if a
   breakpoint is reached */
int cpu_breakpoint_insert(CPUState *env, target_ulong pc)
{
#if defined(TARGET_HAS_ICE)
    int i;
    
    for(i = 0; i < env->nb_breakpoints; i++) {
        if (env->breakpoints[i] == pc)
            return 0;
    }

    if (env->nb_breakpoints >= MAX_BREAKPOINTS)
        return -1;
    env->breakpoints[env->nb_breakpoints++] = pc;
    
    breakpoint_invalidate(env, pc);
    return 0;
#else
    return -1;
#endif
}

/* remove a breakpoint */
int cpu_breakpoint_remove(CPUState *env, target_ulong pc)
{
#if defined(TARGET_HAS_ICE)
    int i;
    for(i = 0; i < env->nb_breakpoints; i++) {
        if (env->breakpoints[i] == pc)
            goto found;
    }
    return -1;
 found:
    env->nb_breakpoints--;
    if (i < env->nb_breakpoints)
      env->breakpoints[i] = env->breakpoints[env->nb_breakpoints];

    breakpoint_invalidate(env, pc);
    return 0;
#else
    return -1;
#endif
}

/* enable or disable single step mode. EXCP_DEBUG is returned by the
   CPU loop after each instruction */
void cpu_single_step(CPUState *env, int enabled)
{
#if defined(TARGET_HAS_ICE)
    if (env->singlestep_enabled != enabled) {
        env->singlestep_enabled = enabled;
        /* must flush all the translated code to avoid inconsistancies */
        /* XXX: only flush what is necessary */
        tb_flush(env);
    }
#endif
}

/* enable or disable low levels log */
void cpu_set_log(int log_flags)
{
    loglevel = log_flags;
    if (loglevel && !logfile) {
        logfile = fopen(logfilename, "w");
        if (!logfile) {
            perror(logfilename);
            _exit(1);
        }
#if !defined(CONFIG_SOFTMMU)
        /* must avoid mmap() usage of glibc by setting a buffer "by hand" */
        {
            static uint8_t logfile_buf[4096];
            setvbuf(logfile, logfile_buf, _IOLBF, sizeof(logfile_buf));
        }
#else
        setvbuf(logfile, NULL, _IOLBF, 0);
#endif
    }
}

void cpu_set_log_filename(const char *filename)
{
    logfilename = strdup(filename);
}

/* mask must never be zero, except for A20 change call */
void cpu_interrupt(CPUState *env, int mask)
{
    TranslationBlock *tb;
    static int interrupt_lock;

    env->interrupt_request |= mask;
    /* if the cpu is currently executing code, we must unlink it and
       all the potentially executing TB */
    tb = env->current_tb;
    if (tb && !testandset(&interrupt_lock)) {
        env->current_tb = NULL;
        tb_reset_jump_recursive(tb);
        interrupt_lock = 0;
    }
}

void cpu_reset_interrupt(CPUState *env, int mask)
{
    env->interrupt_request &= ~mask;
}

CPULogItem cpu_log_items[] = {
    { CPU_LOG_TB_OUT_ASM, "out_asm", 
      "show generated host assembly code for each compiled TB" },
    { CPU_LOG_TB_IN_ASM, "in_asm",
      "show target assembly code for each compiled TB" },
    { CPU_LOG_TB_OP, "op", 
      "show micro ops for each compiled TB (only usable if 'in_asm' used)" },
#ifdef TARGET_I386
    { CPU_LOG_TB_OP_OPT, "op_opt",
      "show micro ops after optimization for each compiled TB" },
#endif
    { CPU_LOG_INT, "int",
      "show interrupts/exceptions in short format" },
    { CPU_LOG_EXEC, "exec",
      "show trace before each executed TB (lots of logs)" },
    { CPU_LOG_TB_CPU, "cpu",
      "show CPU state before bloc translation" },
#ifdef TARGET_I386
    { CPU_LOG_PCALL, "pcall",
      "show protected mode far calls/returns/exceptions" },
#endif
#ifdef DEBUG_IOPORT
    { CPU_LOG_IOPORT, "ioport",
      "show all i/o ports accesses" },
#endif
    { 0, NULL, NULL },
};

static int cmp1(const char *s1, int n, const char *s2)
{
    if (strlen(s2) != n)
        return 0;
    return memcmp(s1, s2, n) == 0;
}
      
/* takes a comma separated list of log masks. Return 0 if error. */
int cpu_str_to_log_mask(const char *str)
{
    CPULogItem *item;
    int mask;
    const char *p, *p1;

    p = str;
    mask = 0;
    for(;;) {
        p1 = strchr(p, ',');
        if (!p1)
            p1 = p + strlen(p);
	if(cmp1(p,p1-p,"all")) {
		for(item = cpu_log_items; item->mask != 0; item++) {
			mask |= item->mask;
		}
	} else {
        for(item = cpu_log_items; item->mask != 0; item++) {
            if (cmp1(p, p1 - p, item->name))
                goto found;
        }
        return 0;
	}
    found:
        mask |= item->mask;
        if (*p1 != ',')
            break;
        p = p1 + 1;
    }
    return mask;
}

void cpu_abort(CPUState *env, const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    fprintf(stderr, "qemu: fatal: ");
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
#ifdef TARGET_I386
    cpu_dump_state(env, stderr, fprintf, X86_DUMP_FPU | X86_DUMP_CCOP);
#else
    cpu_dump_state(env, stderr, fprintf, 0);
#endif
    va_end(ap);
    abort();
}

#if !defined(CONFIG_USER_ONLY)

/* NOTE: if flush_global is true, also flush global entries (not
   implemented yet) */
void tlb_flush(CPUState *env, int flush_global)
{
    int i;

#if defined(DEBUG_TLB)
    printf("tlb_flush:\n");
#endif
    /* must reset current TB so that interrupts cannot modify the
       links while we are modifying them */
    env->current_tb = NULL;

    for(i = 0; i < CPU_TLB_SIZE; i++) {
        env->tlb_table[0][i].addr_read = -1;
        env->tlb_table[0][i].addr_write = -1;
        env->tlb_table[0][i].addr_code = -1;
        env->tlb_table[1][i].addr_read = -1;
        env->tlb_table[1][i].addr_write = -1;
        env->tlb_table[1][i].addr_code = -1;
    }

    memset (env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof (void *));

#if !defined(CONFIG_SOFTMMU)
    munmap((void *)MMAP_AREA_START, MMAP_AREA_END - MMAP_AREA_START);
#endif
#ifdef USE_KQEMU
    if (env->kqemu_enabled) {
        kqemu_flush(env, flush_global);
    }
#endif
    tlb_flush_count++;
}

static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr)
{
    if (addr == (tlb_entry->addr_read & 
                 (TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
        addr == (tlb_entry->addr_write & 
                 (TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
        addr == (tlb_entry->addr_code & 
                 (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
        tlb_entry->addr_read = -1;
        tlb_entry->addr_write = -1;
        tlb_entry->addr_code = -1;
    }
}

void tlb_flush_page(CPUState *env, target_ulong addr)
{
    int i;
    TranslationBlock *tb;

#if defined(DEBUG_TLB)
    printf("tlb_flush_page: " TARGET_FMT_lx "\n", addr);
#endif
    /* must reset current TB so that interrupts cannot modify the
       links while we are modifying them */
    env->current_tb = NULL;

    addr &= TARGET_PAGE_MASK;
    i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
    tlb_flush_entry(&env->tlb_table[0][i], addr);
    tlb_flush_entry(&env->tlb_table[1][i], addr);

    for(i = 0; i < TB_JMP_CACHE_SIZE; i++) {
        tb = env->tb_jmp_cache[i];
        if (tb && 
            ((tb->pc & TARGET_PAGE_MASK) == addr ||
             ((tb->pc + tb->size - 1) & TARGET_PAGE_MASK) == addr)) {
            env->tb_jmp_cache[i] = NULL;
        }
    }

#if !defined(CONFIG_SOFTMMU)
    if (addr < MMAP_AREA_END)
        munmap((void *)addr, TARGET_PAGE_SIZE);
#endif
#ifdef USE_KQEMU
    if (env->kqemu_enabled) {
        kqemu_flush_page(env, addr);
    }
#endif