Patchwork [qom-cpu,07/11] target-i386: check/enforce: Check all CPUID.80000001H.EDX bits

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Submitter Eduardo Habkost
Date Jan. 4, 2013, 10:01 p.m.
Message ID <1357336872-7200-8-git-send-email-ehabkost@redhat.com>
Download mbox | patch
Permalink /patch/209555/
State New
Headers show

Comments

Eduardo Habkost - Jan. 4, 2013, 10:01 p.m.
I have no idea why PPRO_FEATURES was being ignored on the check of the
CPUID.80000001H.EDX bits. I believe it was a mistake, and it was
supposed to be ~(PPRO_FEATURES & CPUID_EXT2_AMD_ALIASES) or just
~CPUID_EXT2_AMD_ALIASES, because some time ago kvm_cpu_fill_host() used
the CPUID instruction directly (instead of
kvm_arch_get_supported_cpuid()).

But now kvm_cpu_fill_host() use kvm_arch_get_supported_cpuid(), and
kvm_arch_get_supported_cpuid() returns all supported bits for
CPUID.80000001H.EDX, even the AMD aliases (that are explicitly copied
from CPUID.01H.EDX), so we can make the code check/enforce all the
CPUID.80000001H.EDX bits.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 target-i386/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Gleb Natapov - Jan. 6, 2013, 2:24 p.m.
On Fri, Jan 04, 2013 at 08:01:08PM -0200, Eduardo Habkost wrote:
> I have no idea why PPRO_FEATURES was being ignored on the check of the
> CPUID.80000001H.EDX bits. I believe it was a mistake, and it was
> supposed to be ~(PPRO_FEATURES & CPUID_EXT2_AMD_ALIASES) or just
> ~CPUID_EXT2_AMD_ALIASES, because some time ago kvm_cpu_fill_host() used
> the CPUID instruction directly (instead of
> kvm_arch_get_supported_cpuid()).
> 
> But now kvm_cpu_fill_host() use kvm_arch_get_supported_cpuid(), and
> kvm_arch_get_supported_cpuid() returns all supported bits for
> CPUID.80000001H.EDX, even the AMD aliases (that are explicitly copied
> from CPUID.01H.EDX), so we can make the code check/enforce all the
> CPUID.80000001H.EDX bits.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>

> ---
>  target-i386/cpu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 42c4c99..ce64b98 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -972,7 +972,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def)
>          {&guest_def->ext_features, &host_def.ext_features,
>              ~0, ext_feature_name, 0x00000001, R_ECX},
>          {&guest_def->ext2_features, &host_def.ext2_features,
> -            ~PPRO_FEATURES, ext2_feature_name, 0x80000001, R_EDX},
> +            ~0, ext2_feature_name, 0x80000001, R_EDX},
>          {&guest_def->ext3_features, &host_def.ext3_features,
>              ~CPUID_EXT3_SVM, ext3_feature_name, 0x80000001, R_ECX}
>      };
> -- 
> 1.7.11.7
> 

--
			Gleb.

Patch

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 42c4c99..ce64b98 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -972,7 +972,7 @@  static int kvm_check_features_against_host(x86_def_t *guest_def)
         {&guest_def->ext_features, &host_def.ext_features,
             ~0, ext_feature_name, 0x00000001, R_ECX},
         {&guest_def->ext2_features, &host_def.ext2_features,
-            ~PPRO_FEATURES, ext2_feature_name, 0x80000001, R_EDX},
+            ~0, ext2_feature_name, 0x80000001, R_EDX},
         {&guest_def->ext3_features, &host_def.ext3_features,
             ~CPUID_EXT3_SVM, ext3_feature_name, 0x80000001, R_ECX}
     };