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From: Gleb Natapov <gleb@redhat.com>
To: "Ren, Yongjie" <yongjie.ren@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	ehabkost@redhat.com
Subject: Re: [PATCH] target-i386: upgrade family number of qemu64 CPU model to 15
Date: Thu, 18 Apr 2013 14:07:56 +0300	[thread overview]
Message-ID: <20130418110756.GT8997@redhat.com> (raw)
In-Reply-To: <1B4B44D9196EFF41AE41FDA404FC0A10C96B9B@SHSMSX101.ccr.corp.intel.com>

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 <yongjie.ren@intel.com>
> ---
>  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.

  reply	other threads:[~2013-04-18 11:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-18 10:45 [PATCH] target-i386: upgrade family number of qemu64 CPU model to 15 Ren, Yongjie
2013-04-18 11:07 ` Gleb Natapov [this message]
2013-04-18 14:47   ` Ren, Yongjie
2013-04-18 14:56     ` Eduardo Habkost

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