Re: [PATCH v4 3/3] xsm: properly handle error from XSM init

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

On 6/1/22 02:49, Jan Beulich wrote:
> On 31.05.2022 21:18, Andrew Cooper wrote:
>> On 31/05/2022 19:20, Daniel P. Smith wrote:
>>> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
>>> index 53a73010e0..ed67b50c9d 100644
>>> --- a/xen/arch/x86/setup.c
>>> +++ b/xen/arch/x86/setup.c
>>> @@ -1700,7 +1701,11 @@ void __init noreturn __start_xen(unsigned long mbi_p)
>>>      mmio_ro_ranges = rangeset_new(NULL, "r/o mmio ranges",
>>>                                    RANGESETF_prettyprint_hex);
>>>  
>>> -    xsm_multiboot_init(module_map, mbi);
>>> +    if ( xsm_multiboot_init(module_map, mbi) )
>>> +        warning_add("WARNING: XSM failed to initialize.\n"
>>> +                    "This has implications on the security of the 
>>> system,\n"
>>> +                    "as uncontrolled communications between trusted and\n"
>>> +                    "untrusted domains may occur.\n");
>>
>> The problem with this approach is that it forces each architecture to
>> opencode the failure string, in a function which is very busy with other
>> things too.
>>
>> Couldn't xsm_{multiboot,dt}_init() be void, and the warning_add() move
>> into them, like the SLIO warning for ARM already?
> 
> I, too, was considering to suggest this (but then didn't on v3). Furthermore
> the warning_add() could then be wrapped in a trivial helper function to be
> used by both MB and DT.

Re: helper function, ack.