Re: [PATCH 4/8] unify paravirt parts of system.h

[Andi Kleen]

On Tue, Dec 04, 2007 at 09:18:33PM +0200, Avi Kivity wrote:
> Glauber de Oliveira Costa wrote:
>> This patch moves the i386 control registers manipulation functions,
>> wbinvd, and clts functions to system.h. They are essentially the same
>> as in x86_64, except for the cr8 register, which we add.
>>
>> +
>> +static inline unsigned long native_read_cr8(void)
>> +{
>> +	unsigned long cr8;
>> +	asm volatile("mov %%cr8,%0" : "=r" (cr8), "=m" (__force_order));
>> +	return cr8;
>> +}
>> +
>>   
>
> There is no cr8 register on i386.  This had better be protected by an 
> #ifdef.
>
> (you're likely not getting an error since it's a static inline, so the asm 
> is never emitted)

Linux never uses that register. The only user is suspend save/restore, 
but that' bogus because it wasn't ever initialized by Linux in the first
place. It could be probably all safely removed.

-Andi

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/