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

Gleb Natapov
2013-01-06T14:25:27Z

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.