I don't know the difference between illegal instruction exception and virtual instruction exception.
For example:
The CSR number of sstatus is 0x100,The CSR number of vsstatus is 0x200.
Q1：When the privilege level is VU, should the CSR instruction access the register numbered 0x100 produce illegal instruction exception or virtual instruction exception?
Q2：When the privilege level is U, should the CSR instruction access the register numbered 0x200 produce illegal instruction exception or virtual instruction exception?
