Re: [PATCH 12/24] x86-64: remove PGE from must-have feature list

H. Peter Anvin
2009-03-15T21:23:06Z

Jeremy Fitzhardinge wrote:
> From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
>
> PGE may not be available when running paravirtualized, so test the cpuid
> bit before using it.
>
> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> ---
> arch/x86/include/asm/required-features.h | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
> index d5cd6c5..a4737dd 100644
> --- a/arch/x86/include/asm/required-features.h
> +++ b/arch/x86/include/asm/required-features.h
> @@ -50,7 +50,7 @@
> #ifdef CONFIG_X86_64
> #define NEED_PSE 0
> #define NEED_MSR (1<<(X86_FEATURE_MSR & 31))
> -#define NEED_PGE (1<<(X86_FEATURE_PGE & 31))
> +#define NEED_PGE 0
> #define NEED_FXSR (1<<(X86_FEATURE_FXSR & 31))
> #define NEED_XMM (1<<(X86_FEATURE_XMM & 31))
> #define NEED_XMM2 (1<<(X86_FEATURE_XMM2 & 31))

This should be conditionalized on CONFIG_PARAVIRT, since doing this
removes real-hardware optimimizations.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.