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

[Avi Kivity <avi@redhat.com>]

On 05/27/2010 12:50 PM, Sheng Yang wrote:
> We can support it in KVM now. The initial values are the minimal requirement
> of XSAVE capable processor.
>
> Signed-off-by: Sheng Yang<sheng@linux.intel.com>
> ---
>   target-i386/cpuid.c |   32 ++++++++++++++++++++++++++++++++
>   1 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
> index eebf038..cbf5595 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; /* FP | SSE | YMM */
> +            *ebx = 0x340; /* FP + SSE + YMM size */
> +            *ecx = 0x340; /* FP + SSE + YMM size */
>    

For -cpu host, we should pick these from KVM_GET_SUPPORTED_CPUID.  For 
canned cpu types (e.g. qemu64), we need to return what we always did.

We can also add a new cpu type that has them built in (there's no cpu on 
the market with avx, right?)

> +            *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; /* YMM size */
> +            *ebx = 0x240; /* YMM offset */
> +            *ecx = 0;
> +            *edx = 0;
>    

These, too.

> +        } else {
> +            *eax = 0;
> +            *ebx = 0;
> +            *ecx = 0;
> +            *edx = 0;
> +        }
> +        break;
>       case 0x80000000:
>           *eax = env->cpuid_xlevel;
>           *ebx = env->cpuid_vendor1;
>    


-- 
error compiling committee.c: too many arguments to function