Re: [Qemu-devel] [PATCH v4 3/3] target-i386:slightly refactor dr7 related function

[Andreas Färber]

This is lacking a proper description of the slight refactoring.

Am 10.12.2012 03:22, schrieb liguang:
> Signed-off-by: liguang <address@hidden>
> ---
>  target-i386/helper.c      |   74 +++++++++++++++++++++++++++++---------------
>  target-i386/machine.c     |    5 ++-
>  target-i386/misc_helper.c |    4 +-
>  target-i386/seg_helper.c  |    7 ++--
>  4 files changed, 58 insertions(+), 32 deletions(-)
> 
> diff --git a/target-i386/helper.c b/target-i386/helper.c
> index bf206cf..62746c5 100644
> --- a/target-i386/helper.c
> +++ b/target-i386/helper.c
> @@ -966,30 +966,33 @@ hwaddr cpu_get_phys_page_debug(CPUX86State *env, 
> target_ulong addr)
>  
>  void hw_breakpoint_insert(CPUX86State *env, int index)
>  {
> -    int type, err = 0;
> +    int type = 0, err = 0;
>  
>      switch (hw_breakpoint_type(env->dr[7], index)) {
> -    case 0:
> -        if (hw_breakpoint_enabled(env->dr[7], index))
> +    case DR7_TYPE_BP_INST:
> +        if (hw_breakpoint_enabled(env->dr[7], index)) {
>              err = cpu_breakpoint_insert(env, env->dr[index], BP_CPU,
>                                          &env->cpu_breakpoint[index]);
> +        }
>          break;
> -    case 1:
> +    case DR7_TYPE_DATA_WR:
>          type = BP_CPU | BP_MEM_WRITE;
> -        goto insert_wp;
> -    case 2:
> -         /* No support for I/O watchpoints yet */
>          break;
> -    case 3:
> +    case DR7_TYPE_DATA_RW:
>          type = BP_CPU | BP_MEM_ACCESS;
> -    insert_wp:
> +        break;
> +     case DR7_TYPE_IO_RW:

Tab should be four spaces.

> +        /* No support for I/O watchpoints yet */
> +        break;
> +    }
> +     if (type) {

Another tab.

>          err = cpu_watchpoint_insert(env, env->dr[index],
>                                      hw_breakpoint_len(env->dr[7], index),
>                                      type, &env->cpu_watchpoint[index]);
> -        break;
>      }
> -    if (err)
> +    if (err) {
>          env->cpu_breakpoint[index] = NULL;
> +    }
>  }
>  
>  void hw_breakpoint_remove(CPUX86State *env, int index)
> @@ -997,15 +1000,16 @@ void hw_breakpoint_remove(CPUX86State *env, int index)
>      if (!env->cpu_breakpoint[index])
>          return;
>      switch (hw_breakpoint_type(env->dr[7], index)) {
> -    case 0:
> -        if (hw_breakpoint_enabled(env->dr[7], index))
> +    case DR7_TYPE_BP_INST:
> +        if (hw_breakpoint_enabled(env->dr[7], index)) {
>              cpu_breakpoint_remove_by_ref(env, env->cpu_breakpoint[index]);
> +        }
>          break;
> -    case 1:
> -    case 3:
> +    case DR7_TYPE_DATA_RW:
> +    case DR7_TYPE_DATA_WR:
>          cpu_watchpoint_remove_by_ref(env, env->cpu_watchpoint[index]);
>          break;
> -    case 2:
> +    case DR7_TYPE_IO_RW:
>          /* No support for I/O watchpoints yet */
>          break;
>      }
> @@ -1014,22 +1018,42 @@ void hw_breakpoint_remove(CPUX86State *env, int index)
>  int check_hw_breakpoints(CPUX86State *env, int force_dr6_update)
>  {
>      target_ulong dr6;
> -    int reg, type;
> +    int index;
>      int hit_enabled = 0;
> +    bool bp_match = false;
> +    bool wp_match = false;
>  
>      dr6 = env->dr[6] & ~0xf;
> -    for (reg = 0; reg < 4; reg++) {
> -        type = hw_breakpoint_type(env->dr[7], reg);
> -        if ((type == 0 && env->dr[reg] == env->eip) ||
> -            ((type & 1) && env->cpu_watchpoint[reg] &&
> -             (env->cpu_watchpoint[reg]->flags & BP_WATCHPOINT_HIT))) {
> -            dr6 |= 1 << reg;
> -            if (hw_breakpoint_enabled(env->dr[7], reg))
> +     for (index = 0; index < DR7_MAX_BP; index++) {
> +        switch (hw_breakpoint_type(env->dr[7], index)) {
> +        case DR7_TYPE_BP_INST:
> +            if (env->dr[index] == env->eip) {
> +                bp_match = true;
> +            }
> +            break;
> +        case DR7_TYPE_DATA_WR:
> +        case DR7_TYPE_DATA_RW:
> +            if (env->cpu_watchpoint[index] &&
> +                env->cpu_watchpoint[index]->flags & BP_WATCHPOINT_HIT) {
> +                wp_match = true;
> +            }
> +                     break;
> +        case DR7_TYPE_IO_RW:
> +            break;
> +        }
> +        if (bp_match || wp_match) {
> +            dr6 |= 1 << index;
> +            if (hw_breakpoint_enabled(env->dr[7], index)) {
>                  hit_enabled = 1;
> +            }
> +            bp_match = false;
> +            wp_match = false;
>          }
>      }
> -    if (hit_enabled || force_dr6_update)
> +    if (hit_enabled || force_dr6_update) {
>          env->dr[6] = dr6;
> +     }
> +
>      return hit_enabled;
>  }
>  
> diff --git a/target-i386/machine.c b/target-i386/machine.c
> index 4771508..67131a4 100644
> --- a/target-i386/machine.c
> +++ b/target-i386/machine.c
> @@ -265,10 +265,11 @@ static int cpu_post_load(void *opaque, int version_id)
>  
>      cpu_breakpoint_remove_all(env, BP_CPU);
>      cpu_watchpoint_remove_all(env, BP_CPU);
> -    for (i = 0; i < 4; i++)
> +    for (i = 0; i < DR7_MAX_BP; i++) {

This trivial change could be in 1/3.

>          hw_breakpoint_insert(env, i);
> -
> +     }

Tab.

>      tlb_flush(env, 1);
> +
>      return 0;
>  }
>  
> diff --git a/target-i386/misc_helper.c b/target-i386/misc_helper.c
> index a020379..5ee0863 100644
> --- a/target-i386/misc_helper.c
> +++ b/target-i386/misc_helper.c
> @@ -197,11 +197,11 @@ void helper_movl_drN_T0(CPUX86State *env, int reg, 
> target_ulong t0)
>          env->dr[reg] = t0;
>          hw_breakpoint_insert(env, reg);
>      } else if (reg == 7) {
> -        for (i = 0; i < 4; i++) {
> +        for (i = 0; i < DR7_MAX_BP; i++) {
>              hw_breakpoint_remove(env, i);
>          }
>          env->dr[7] = t0;
> -        for (i = 0; i < 4; i++) {
> +        for (i = 0; i < DR7_MAX_BP; i++) {
>              hw_breakpoint_insert(env, i);
>          }
>      } else {

Move both into 1/3?

> diff --git a/target-i386/seg_helper.c b/target-i386/seg_helper.c
> index ff93374..306e9d1 100644
> --- a/target-i386/seg_helper.c
> +++ b/target-i386/seg_helper.c
> @@ -465,9 +465,10 @@ static void switch_tss(CPUX86State *env, int 
> tss_selector,
>  
>  #ifndef CONFIG_USER_ONLY
>      /* reset local breakpoints */
> -    if (env->dr[7] & 0x55) {
> -        for (i = 0; i < 4; i++) {
> -            if (hw_breakpoint_enabled(env->dr[7], i) == 0x1) {
> +    if (env->dr[7] & DR7_LOCAL_BP_MASK) {
> +        for (i = 0; i < DR7_MAX_BP; i++) {

1/3?

> +            if (hw_local_breakpoint_enabled(env->dr[7], i) &&
> +                !hw_global_breakpoint_enabled(env->dr[7], i)) {
>                  hw_breakpoint_remove(env, i);
>              }
>          }

Regards,
Andreas

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