[PATCH v3] lib: sbi: Enable Ssqosid Ext using mstateen0

[Radim Krčmář]

2025-11-11T17:49:36+08:00, <cp0613 at linux.alibaba.com>:
> On 2025-11-10 02:41 PM, Radim Krčmář wrote:
>> >                                         so there is no need to consider the execution
>> > situation in M-mode, it is only necessary to enable the relevant permissions.
>> 
>> The execution of M-mode is affected by srmcfg, so we have to be
>> extremely careful about isolation in opensbi too, especially when
>> juggling multiple domains.
>> 
>> (I think we might be fine now, but having opensbi switch to a srmcfg
>>  that isn't controlled by S-mode will result in a lot less headaches...)
>> 
>> Thanks.
>
> Indeed, strictly speaking, the execution of M-mode is also affected by srmcfg.
> When dealing with multiple domains, attention needs to be paid to isolation and
> context switching issues. I understand your point of view.
>
> However, I wonder if it could be done in a later stage of the work, because there
> is currently a draft specification smmtt[1] that is also related to this. This
> extension involves multiple Supervisor Domains, and at this time, it is necessary
> to implement context switching of srmcfg between different domains.

I agree that we can return to that issue later, as it's not clearly
buggy for now.  For this patch, I would just like to fix the condition.

Thanks.