Re: [PATCH v3 1/3] xsm: only search for a policy file when needed

[Jan Beulich <jbeulich@xxxxxxxx>]

On 31.05.2022 18:15, Daniel P. Smith wrote:
> 
> On 5/31/22 11:51, Jan Beulich wrote:
>> On 31.05.2022 17:08, Daniel P. Smith wrote:
>>> It is possible to select a few different build configurations that results 
>>> in
>>> the unnecessary walking of the boot module list looking for a policy module.
>>> This specifically occurs when the flask policy is enabled but either the 
>>> dummy
>>> or the SILO policy is selected as the enforcing policy. This is not ideal 
>>> for
>>> configurations like hyperlaunch and dom0less when there could be a number of
>>> modules to be walked or doing an unnecessary device tree lookup.
>>>
>>> This patch introduces the policy_file_required flag for tracking when an XSM
>>> policy module requires a policy file. Only when the policy_file_required 
>>> flag
>>> is set to true, will XSM search the boot modules for a policy file.
>>>
>>> Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
>>
>> Looks technically okay, so
>> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
>> but couldn't you ...
>>
>>> @@ -148,7 +160,7 @@ int __init xsm_multiboot_init(
>>>  
>>>      printk("XSM Framework v" XSM_FRAMEWORK_VERSION " initialized\n");
>>>  
>>> -    if ( XSM_MAGIC )
>>> +    if ( policy_file_required && XSM_MAGIC )
>>>      {
>>>          ret = xsm_multiboot_policy_init(module_map, mbi, &policy_buffer,
>>>                                          &policy_size);
>>> @@ -176,7 +188,7 @@ int __init xsm_dt_init(void)
>>>  
>>>      printk("XSM Framework v" XSM_FRAMEWORK_VERSION " initialized\n");
>>>  
>>> -    if ( XSM_MAGIC )
>>> +    if ( policy_file_required && XSM_MAGIC )
>>>      {
>>>          ret = xsm_dt_policy_init(&policy_buffer, &policy_size);
>>>          if ( ret )
>>
>> ... drop the two "&& XSM_MAGIC" here at this time? Afaict 
>> policy_file_required
>> cannot be true when XSM_MAGIC is zero.
> 
> I was on the fence about this, as it should be rendered as redundant as
> you point out. I am good with dropping on next spin.

I'd also be okay dropping this while committing, unless a v4 appears
first ...

Jan