[Qemu-devel] Re: [PATCH 3/3] Add svm cpuid features

[Avi Kivity <avi@redhat.com>]

  On 09/28/2010 12:05 PM, Roedel, Joerg wrote:
> On Tue, Sep 28, 2010 at 05:37:58AM -0400, Avi Kivity wrote:
> >    On 09/28/2010 11:28 AM, Roedel, Joerg wrote:
>
> >  >  Weird, it worked here as I tested it. I had it on qemu/master and with
> >  >  all three patches. But patch 1 should not make the difference. I take a
> >  >  look, have you pushed the failing uq/master?
> >
> >  Yes, 8fe6a21c76.
> >
> >  >  What was your command line?
> >
> >  qemu-system-x86_64 -m 2G -cpu kvm64,+svm,+npt -enable-kvm ...
> >
> >  Note this is qemu.git, so -enable-kvm is needed.
>
> Ok, I apparently forgot to force the CPUID xlevel to be 0x8000000A when
> SVM is enabled, probably because I only tested CPUID models where xlevel
> already defaults to 0x8000000A. Attached is a fix, thanks for catching
> this.
>
> 	Joerg
>
>
>  From d18d973d037f1af1869e114aea1f076ea3a1ee7a Mon Sep 17 00:00:00 2001
> From: Joerg Roedel<joerg.roedel@amd.com>
> Date: Tue, 28 Sep 2010 11:58:49 +0200
> Subject: [PATCH 1/1] qemu: Force xlevel to at least 0x8000000A if SVM is enabled
>
> This patch forces the extended CPUID level to be at least
> 0x8000000A if SVM is enabled in the CPU model.
>
> Signed-off-by: Joerg Roedel<joerg.roedel@amd.com>
> ---
>   target-i386/cpuid.c |    5 +++++
>   1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
> index 0e0bf60..0630fe1 100644
> --- a/target-i386/cpuid.c
> +++ b/target-i386/cpuid.c
> @@ -714,6 +714,11 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
>       x86_cpu_def->ext3_features&= ~minus_ext3_features;
>       x86_cpu_def->kvm_features&= ~minus_kvm_features;
>       x86_cpu_def->svm_features&= ~minus_svm_features;
> +    if ((x86_cpu_def->ext3_features&  CPUID_EXT3_SVM)&&
> +        (x86_cpu_def->xlevel<  0x8000000A)) {
> +        /* Force xlevel to at least 0x8000000A if SVM enabled */
> +        x86_cpu_def->xlevel = 0x8000000A;
> +    }
>       if (check_cpuid) {
>           if (check_features_against_host(x86_cpu_def)&&  enforce_cpuid)
>               goto error;

I can't say I like the interdependency, but saying something like -cpu 
kvm64,+svm,xlevel=0x8000000a is much worse.

If no one has a better idea, I'll apply the patch.

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