Re: [PATCH 5/13] KVM: virtualization infrastructure

[Avi Kivity <avi@qumranet.com>]

Arnd Bergmann wrote:
> On Monday 23 October 2006 22:28, Avi Kivity wrote:
>
>   
>>>> +struct segment_descriptor {
>>>> +    u16 limit_low;
>>>> +    u16 base_low;
>>>> +    u8  base_mid;
>>>> +    u8  type : 4;
>>>> +    u8  system : 1;
>>>> +    u8  dpl : 2;
>>>> +    u8  present : 1;
>>>> +    u8  limit_high : 4;
>>>> +    u8  avl : 1;
>>>> +    u8  long_mode : 1;
>>>> +    u8  default_op : 1;
>>>> +    u8  granularity : 1;
>>>> +    u8  base_high;
>>>> +} __attribute__((packed));
>>>>    
>>>>         
>>> Bitfields are generally frowned upon. It's better to define
>>> constants for each of these and use a u64.
>>>       
>> Any specific reasons?  I find the code much more readable (and
>> lowercase) with bitfields.
>>     
>
> The strongest reason against bitfields is that they are not
> endian-clean. This doesn't apply on a architecture-specific
> patch such as KVM, but it just feels wrong to read code
> with bit fields in the kernel.
>
>   

This structure is suspiciously similar to struct desc_struct in 
asm-x86_64/desc.h.

However, I can't use it because asm-i386/desc.h does not have a similar 
definition.


Andi, will you accept a patch to move it to asm-i386/desc_defs.h so it 
can be used in both archs?

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