[BUG] <Unknown Values on performance counters>

Created by: AyoubJalali

Is there an existing CVA6 bug for this?

• I have searched the existing bug issues

Bug Description

Hello, The problem here is the a got unknown values on the performance counters (mhpmcounter-h & mhpmevent).

core 0: 0x0000000080000b0c (0xb1e792f3) csrrw t0, mhpmcounter30, a5 3 0x0000000080000b0c (0xb1e792f3) x 5 0xxxxxxxxx (example)

so to reproduce the problem you have to :

• Add the yaml description of the test in cva6_base_testlist.yaml

• test: riscv_arithmetic_basic_hint_illegal_csr_test description: > Arithmetic instruction test, no load/store/branch instructions gen_opts: > +instr_cnt=500 +num_of_sub_program=5 +directed_instr_0=riscv_int_numeric_corner_stream,4 +no_data_page=1 +no_branch_jump=1 +boot_mode=m +no_csr_instr=0 +enable_illegal_csr_instruction=1 +hint_instr_ratio=100 +tvec_alignment=8 iterations: 2 gen_test: riscv_instr_base_test rtl_test: core_base_test

and run the commend :

1. python3 cva6.py --testlist=cva6_base_testlist.yaml --test riscv_arithmetic_basic_hint_illegal_csr_test --iss_yaml cva6.yaml --target cv32a60x --iss=vcs-uvm,spike -i 1 --iss_timeout 300 --seed 3018203365 (bug on mhpmcounter12h)

2. python3 cva6.py --testlist=cva6_base_testlist.yaml --test riscv_arithmetic_basic_hint_illegal_csr_test --iss_yaml cva6.yaml --target cv32a60x --iss=vcs-uvm,spike -i 1 --iss_timeout 300 --seed 2951308182 (bug on mhpmcounter15)

3. python3 cva6.py --testlist=cva6_base_testlist.yaml --test riscv_arithmetic_basic_hint_illegal_csr_test --iss_yaml cva6.yaml --target cv32a60x --iss=vcs-uvm,spike -i 1 --iss_timeout 300 --seed 1147271990 (bug on mhpmevent8)

in core-v-verif/cva6/sim (branch cva6/dev & RTL matser), definitely you gonna find one of test failed because of an unknown values on these perform counter without seeds if you want to.