Re: [Xen-devel] [PATCH 03/14] xen/x86: Make mfn_to_gfn typesafe

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 10.05.19 at 15:02, <julien.grall@xxxxxxx> wrote:

> 
> On 10/05/2019 12:35, Jan Beulich wrote:
>>>>> On 07.05.19 at 17:14, <julien.grall@xxxxxxx> wrote:
>>> --- a/xen/arch/x86/mm/shadow/common.c
>>> +++ b/xen/arch/x86/mm/shadow/common.c
>>> @@ -474,7 +474,8 @@ static inline void trace_resync(int event, mfn_t gmfn)
>>>       if ( tb_init_done )
>>>       {
>>>           /* Convert gmfn to gfn */
>>> -        unsigned long gfn = mfn_to_gfn(current->domain, gmfn);
>>> +        unsigned long gfn = gfn_x(mfn_to_gfn(current->domain, gmfn));
>>> +
>>>           __trace_var(event, 0/*!tsc*/, sizeof(gfn), &gfn);
>>>       }
>> 
>> Can't you use gfn_t here, and hence avoid the gfn_x()? Same again further
>> down.
> Because __trace_var will export the value to the guest. I wasn't sure 
> whether we 
> can safely consider that gfn_t is exactly the same as unsigned long in 
> debug-build.

Hmm, well - see the definition of gfn_t. George, what do you think?

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel