Re: [PATCH] use upstream cpuid code

[Glauber Costa <glommer@redhat.com>]

On Mon, Aug 03, 2009 at 02:57:47PM +0300, Avi Kivity wrote:
> On 07/28/2009 11:05 PM, Glauber Costa wrote:
>> use cpuid code from upstream. By doing that, we lose the following snippet
>> in kvm_get_supported_cpuid():
>>
>>      ret |= 1<<  12; /* MTRR */
>>      ret |= 1<<  16; /* PAT */
>>      ret |= 1<<  7;  /* MCE */
>>      ret |= 1<<  14; /* MCA */
>>
>> A quick search in mailing lists says this code is not really necessary, and we're
>> keeping it just for backwards compatibility. This is not that important, because
>> we'd lose it anyway in the golden day in which we totally merge with qemu.
>> Anyway, if it do _is_ important, we can send a patch to qemu with it.
>>    
>
> It is important.  Please don't introduce regressions (if you do,  
> introduce them in separate patches).  The procedure to drop such  
> workarounds for kernel bugs is to verify that major distros have the  
> kernel fixes in their supported kernels.
Since this was introduced to fix a bug that did not even existed in Windows,
I can't see what you mean by "distro kernels" here.