Re: [Qemu-devel] [PATCH] target-i386: upgrade family number of qemu64 CPU model to 15

[Gleb Natapov]

On Thu, Apr 18, 2013 at 10:45:38AM +0000, Ren, Yongjie wrote:
> qemu64 is the default CPU model for QEMU/KVM on x86-64, but its family number 
> definition is not accurate. The vendor of 'qemu64' is defined as 'AMD'. For 
> AMD 
> processors, AMD K8 (i.e. Family 15) firstly introduced SSE3 instruction set. 
> 'qemu64' already has 'CPUID_EXT_SSE3' in its ext_features, but its family 
> number is only 6 which is not equal to or greater than 15.
> So, upgrade the CPU family number of qemu64 model to 15.
> After this upgrade, 32bit Windows 8 can boot up with qemu64 CPU model.
> This upgrade can be also a fix to the below bug about 32bit Windows 8 booting.
> https://bugs.launchpad.net/qemu/+bug/1007269

Changing cpuid info is not that simple since this is guest visible
information and can impact migration. Old machine models should still
expose the old family.

> 
> Signed-off-by: Yongjie Ren <address@hidden>
> ---
>  target-i386/cpu.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index e2302d8..3f8e6c3 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -420,7 +420,7 @@ static x86_def_t builtin_x86_defs[] = {
>          .name = "qemu64",
>          .level = 4,
>          .vendor = CPUID_VENDOR_AMD,
> -        .family = 6,
> +        .family = 15,
>          .model = 2,
>          .stepping = 3,
>          .features = PPRO_FEATURES |
> --
> 1.7.1

--
                        Gleb.