Re: [Xen-devel] [PATCH 10/20] xsm: Add IS_PRIV checks to dummy XSM module

[Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>]

On 09/11/2012 03:44 AM, Jan Beulich wrote:
>>>> On 10.09.12 at 21:49, Daniel De Graaf <dgdegra@xxxxxxxxxxxxx> wrote:
>> --- a/xen/include/xsm/xsm.h
>> +++ b/xen/include/xsm/xsm.h
>> @@ -21,11 +21,7 @@
>>  typedef void xsm_op_t;
>>  DEFINE_XEN_GUEST_HANDLE(xsm_op_t);
>>  
>> -#ifdef XSM_ENABLE
>> -    #define xsm_call(fn) xsm_ops->fn
>> -#else
>> -    #define xsm_call(fn) 0
>> -#endif
>> +#define xsm_call(fn) xsm_ops->fn
> 
> So am I getting it right that with XSM disabled this now adds an
> indirect call in almost every hypercall? I'm not really in favor of
> that, particularly not if that affects hot path ones like the MMU
> operations.
> 
> Jan
> 

No. With XSM disabled, this part of the header file is not used;
instead, xsm/dummy.h is included with XSM_DEFAULT set up to generate
inline functions. So there should be no slowdown if XSM is disabled.

-- 
Daniel De Graaf
National Security Agency

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel