Is shared memoy exclusive for the setting hart?

[inochisa]

The doc defines shared memory between SBI and S-mode software at here. It says that SBI implementation needs to check S-mode software access type. I wonder whether SBI implementation needs to check the access type for all harts? or only the setting hart?

And one step further, can SBI implementation assume the share memory is exclusively owned by the setting hart and other harts have no access to it before stopping sharing?

[atishp04]

The doc defines shared memory between SBI and S-mode software at here. It says that SBI implementation needs to check S-mode software access type. I wonder whether SBI implementation needs to check the access type for all harts? or only the setting hart?

Only the setting hart. If S-mode cares about enabling on every hart, it should be invoked from every hart.

And one step further, can SBI implementation assume the share memory is exclusively owned by the setting hart and other harts have no access to it before stopping sharing?

Nope. SBI implementation can not make that assumption. Ideally, S-mode software would allocate memory and store it in a per cpu data structure. But SBI implementation can not trust S/VS mode software to do the correct thing always.