[Qemu-devel] Re: [PATCH] qemu-kvm: Enable xsave related CPUID

[Avi Kivity]

On 05/19/2010 11:34 AM, Sheng Yang wrote:
> Signed-off-by: Sheng Yang<address@hidden>
> ---
>   target-i386/cpuid.c |   32 ++++++++++++++++++++++++++++++++
>    

Can send to Anthony directly, while tcg doesn't support xsave/ymm, all 
the code here is generic.

>   1 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
> index eebf038..21e94f3 100644
> --- a/target-i386/cpuid.c
> +++ b/target-i386/cpuid.c
> @@ -1067,6 +1067,38 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
> uint32_t count,
>           *ecx = 0;
>           *edx = 0;
>           break;
> +    case 0xD:
> +        /* Processor Extended State */
> +        if (!(env->cpuid_ext_features&  CPUID_EXT_XSAVE)) {
> +            *eax = 0;
> +            *ebx = 0;
> +            *ecx = 0;
> +            *edx = 0;
> +            break;
> +        }
> +        if (count == 0) {
> +            *eax = 0x7;
> +            *ebx = 0x340;
> +            *ecx = 0x340;
> +            *edx = 0;
> +        } else if (count == 1) {
> +            /* eax = 1, so we can continue with others */
> +            *eax = 1;
> +            *ebx = 0;
> +            *ecx = 0;
> +            *edx = 0;
> +        } else if (count == 2) {
> +            *eax = 0x100;
> +            *ebx = 0x240;
> +            *ecx = 0;
> +            *edx = 0;
> +        } else {
> +            *eax = 0;
> +            *ebx = 0;
> +            *ecx = 0;
> +            *edx = 0;
> +        }
> +        break;
>    

Lots of magic numbers.  Symbolic constants or explanatory comments.

--
Do not meddle in the internals of kernels, for they are subtle and quick to 
panic.