Re: [PATCH 17/24] XSM: make Argo hooks well-formed ones

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.08.2026 23:01, Jason Andryuk wrote:
> On 2026-07-28 09:22, Jan Beulich wrote:
>> --- a/xen/include/xsm/dummy.h
>> +++ b/xen/include/xsm/dummy.h
> 
>> @@ -751,27 +751,32 @@ static XSM_INLINE int xsm_dm_op(XSM_DEFA
>>   #endif
>>   
>>   #ifdef CONFIG_ARGO
>> -static XSM_INLINE int xsm_argo_enable(const struct domain *d)
>> +
>> +static XSM_INLINE int xsm_argo_enable(XSM_DEFAULT_ARG const struct domain 
>> *d)
>>   {
>> -    return 0;
>> +    XSM_ASSERT_ACTION(XSM_HOOK);
>> +    return xsm_default_action(action, current->domain, d);
> 
> This one I think should be
>      return xsm_default_action(action, d, NULL);
> 
> Usually current is passed in for the check, but for domain_create() -> 
> argo_init() it is the under-construction domain.

And in that case we want to make sure that current->domain may enable Argo
for d.

>>   }
>>   
>>   static XSM_INLINE int xsm_argo_register_single_source(
>> -    const struct domain *d, const struct domain *t)
>> +    XSM_DEFAULT_ARG const struct domain *d, const struct domain *t)
>>   {
>> -    return 0;
>> +    XSM_ASSERT_ACTION(XSM_HOOK);
>> +    return xsm_default_action(action, d, t);
>>   }
>>   
>>   static XSM_INLINE int xsm_argo_register_any_source(
>> -    const struct domain *d)
>> +    XSM_DEFAULT_ARG const struct domain *d)
>>   {
>> -    return 0;
>> +    XSM_ASSERT_ACTION(XSM_HOOK);
>> +    return xsm_default_action(action, current->domain, d);
> 
> Similarly:
>      return xsm_default_action(action, d, NULL);
> 
> The single call is:
> xsm_argo_register_any_source(currd);

There being just a single call puts this on the edge. If there was another
one not passing current->domain, I think the same argument as above would
hold here. And the general concept is what I think should matter when
writing the dummy implementations.

> These argo hooks all pass in their arguments explicitly, so I think we 
> should do that and not use current.  (The send and register hooks could 
> use current, and that could make sense as those map to hypercalls.  But 
> it is correct today with the explicit arguments.)
> 
> With the changes:
> Reviewed-by: Jason Andryuk <jason.andryuk@xxxxxxx>

Thanks, but no - unless I misunderstand how permissions are intended to
work here, I don't think I can make the changes requested, and hence I
can't apply the R-b.

Jan