Am 20.01.2014 17:41, schrieb Eduardo Habkost:
> There's no need to check CPU xlevel2 before calling
> kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX), because:
>
> * The kernel won't return any entry for 0xC0000000 if host CPU vendor
> is not Centaur (See kvm_dev_ioctl_get_supported_cpuid() on the kernel
> code)
> * Similarly, the kernel won't return any entry for 0xC0000001 if
> CPUID[0xC0000000].EAX is < 0xC0000001
> * kvm_arch_get_supported_cpuid() will return 0 if no entry is returned
> by the kernel for the requested leaf
>
> For similar reasons, we can simply set x86_cpu_def->xlevel2 directly
> instead of making it conditional, because it will be set to 0 CPU vendor
> is not Centaur.
Commented on the wrong version:
"... if CPU vendor is not ..." I guess. :)
>
> This will simplify the kvm_cpu_fill_host() code a little.
>
> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> ---
> target-i386/cpu.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 1a86bcf..8bc72c2 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -1173,13 +1173,11 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def)
> cpu_x86_fill_model_id(x86_cpu_def->model_id);
>
> /* Call Centaur's CPUID instruction. */
> - eax = kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
> - if (eax >= 0xC0000001) {
> - /* Support VIA max extended level */
> - x86_cpu_def->xlevel2 = eax;
> - x86_cpu_def->features[FEAT_C000_0001_EDX] =
> - kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX);
> - }
> + x86_cpu_def->xlevel2 =
> + kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
> + /* Support VIA max extended level */
> + x86_cpu_def->features[FEAT_C000_0001_EDX] =
> + kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX);
>
> /* Other KVM-specific feature fields: */
> x86_cpu_def->features[FEAT_SVM] =
Otherwise looks okay to me.
Andreas
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