Re: [PATCH] UefiCpuPkg/CpuDxe: Remove MSR_IA32_MISC_ENABLE check

[Anthony PERARD <anthony.perard@citrix.com>]

On Wed, Mar 15, 2017 at 09:54:30AM +0800, Jeff Fan wrote:
> The architectural MSR MSR_IA32_MISC_ENABLE is not supported by AMD processors.
> Because reading CPUID.80000001H:EDK[20] is enough to check if XD feature is
> supported or not, we just remove checking MSR_IA32_MISC_ENABLE(0x1A0).
> 
> Cc: Anthony PERARD <anthony.perard@citrix.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Feng Tian <feng.tian@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jeff Fan <jeff.fan@intel.com>

Thanks, that works for me. I've tested on AMD and Intel machine, with
Xen.

Tested-by: Anthony PERARD <anthony.perard@citrix.com>

> ---
>  UefiCpuPkg/CpuDxe/CpuPageTable.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/UefiCpuPkg/CpuDxe/CpuPageTable.c b/UefiCpuPkg/CpuDxe/CpuPageTable.c
> index 65f607a..ab664b4 100644
> --- a/UefiCpuPkg/CpuDxe/CpuPageTable.c
> +++ b/UefiCpuPkg/CpuDxe/CpuPageTable.c
> @@ -193,12 +193,9 @@ GetCurrentPagingContext (
>      AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);
>      if ((RegEdx & BIT20) != 0) {
>        // XD supported
> -      if ((AsmReadMsr64 (0x000001A0) & BIT34) == 0) {
> -        // XD enabled
> -        if ((AsmReadMsr64 (0xC0000080) & BIT11) != 0) {
> -          // XD activated
> -          PagingContext->ContextData.Ia32.Attributes |= PAGE_TABLE_LIB_PAGING_CONTEXT_IA32_X64_ATTRIBUTES_XD_ACTIVATED;
> -        }
> +      if ((AsmReadMsr64 (0xC0000080) & BIT11) != 0) {
> +        // XD activated
> +        PagingContext->ContextData.Ia32.Attributes |= PAGE_TABLE_LIB_PAGING_CONTEXT_IA32_X64_ATTRIBUTES_XD_ACTIVATED;
>        }
>      }
>      if ((RegEdx & BIT26) != 0) {
> -- 
> 2.9.3.windows.2
> 

-- 
Anthony PERARD