Re: [Qemu-devel] [PATCH qom-cpu 09/11] target-i386: check/enforce: Eliminate check_feat field

[Gleb Natapov <gleb@redhat.com>]

On Fri, Jan 04, 2013 at 08:01:10PM -0200, Eduardo Habkost wrote:
> Now that all entries have check_feat=~0 on
> kvm_check_features_against_host(), we can eliminate check_feat entirely
> and make the code check all bits.
> 
> This patch shouldn't introduce any behavior change, as check_feat is set
> to ~0 on all entries.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>

> ---
> Changes v2:
>  - Coding style fix
> ---
>  target-i386/cpu.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index a9dd959..1c3c7e1 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -148,7 +148,6 @@ const char *get_register_name_32(unsigned int reg)
>  typedef struct model_features_t {
>      uint32_t *guest_feat;
>      uint32_t *host_feat;
> -    uint32_t check_feat;
>      const char **flag_names;
>      uint32_t cpuid;
>      int reg;
> @@ -956,8 +955,7 @@ static int unavailable_host_feature(struct model_features_t *f, uint32_t mask)
>  }
>  
>  /* best effort attempt to inform user requested cpu flags aren't making
> - * their way to the guest.  Note: ft[].check_feat ideally should be
> - * specified via a guest_def field to suppress report of extraneous flags.
> + * their way to the guest.
>   *
>   * This function may be called only if KVM is enabled.
>   */
> @@ -968,13 +966,13 @@ static int kvm_check_features_against_host(x86_def_t *guest_def)
>      int rv, i;
>      struct model_features_t ft[] = {
>          {&guest_def->features, &host_def.features,
> -            ~0, feature_name, 0x00000001, R_EDX},
> +            feature_name, 0x00000001, R_EDX},
>          {&guest_def->ext_features, &host_def.ext_features,
> -            ~0, ext_feature_name, 0x00000001, R_ECX},
> +            ext_feature_name, 0x00000001, R_ECX},
>          {&guest_def->ext2_features, &host_def.ext2_features,
> -            ~0, ext2_feature_name, 0x80000001, R_EDX},
> +            ext2_feature_name, 0x80000001, R_EDX},
>          {&guest_def->ext3_features, &host_def.ext3_features,
> -            ~0, ext3_feature_name, 0x80000001, R_ECX}
> +            ext3_feature_name, 0x80000001, R_ECX}
>      };
>  
>      assert(kvm_enabled());
> @@ -982,7 +980,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def)
>      kvm_cpu_fill_host(&host_def);
>      for (rv = 0, i = 0; i < ARRAY_SIZE(ft); ++i)
>          for (mask = 1; mask; mask <<= 1)
> -            if (ft[i].check_feat & mask && *ft[i].guest_feat & mask &&
> +            if (*ft[i].guest_feat & mask &&
>                  !(*ft[i].host_feat & mask)) {
>                      unavailable_host_feature(&ft[i], mask);
>                      rv = 1;
> -- 
> 1.7.11.7
> 

--
			Gleb.