Re: [Qemu-devel] Re: [PATCH 1/3] kvm-unit-tests: add x86 port io accessors

[Anthony Liguori <anthony@codemonkey.ws>]

On 02/27/2011 06:44 AM, Avi Kivity wrote:
> On 02/24/2011 11:48 PM, Anthony Liguori wrote:
>> Signed-off-by: Anthony Liguori<aliguori@us.ibm.com>
>>
>> diff --git a/lib/x86/io.h b/lib/x86/io.h
>> new file mode 100644
>> index 0000000..bd6341c
>> --- /dev/null
>> +++ b/lib/x86/io.h
>> @@ -0,0 +1,40 @@
>> +#ifndef IO_H
>> +#define IO_H
>> +
>> +static inline unsigned char inb(unsigned short port)
>> +{
>> +    unsigned char value;
>> +    asm volatile("inb %w1, %0" : "=a" (value) : "Nd" (port));
>> +    return value;
>> +}
>
> Are those %[wb] really needed?  gcc should do the right thing based on 
> the argument type.

It's just a little extra type safety.

>
> Might as well put all of that into processor.h.

Seems reasonable.

Regards,

Anthony Liguori