SFENCE.VMA instruction privilege

[Seo-sang]

Can sfence.vma instruction be executed in supervisor mode?
I think both 'S' and 'M' modes are possible, but spike doesn't support it in 'M' mode.
Also, it doesn't work even though I changed the code as below in sfence_vma.h file.
require_extension('S') -> require_extension('M')
Is there any solution to support sfence.vma in 'M' mode?

Thank you.

[aswaterman]

Spike does allow SFENCE.VMA to be executed in M-mode, but only if the implementation supports S-mode. This is the correct behavior.