Re: [PATCH 3/3] target/riscv: Don't assume PMU counters are continuous

[LIU Zhiwei <zhiwei_liu@linux.alibaba.com>]

On 2023/10/3 20:49, Rob Bradford wrote:
> Check the PMU available bitmask when checking if a counter is valid
> rather than comparing the index against the number of PMUs.
>
> Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
> ---
>   target/riscv/csr.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 85a31dc420..3e126219ba 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -182,7 +182,8 @@ static RISCVException zcmt(CPURISCVState *env, int csrno)
>   #if !defined(CONFIG_USER_ONLY)
>   static RISCVException mctr(CPURISCVState *env, int csrno)
>   {
> -    int pmu_num = riscv_cpu_cfg(env)->pmu_num;
> +    RISCVCPU *cpu = RISCV_CPU(env_cpu(env));
Use env_archcpu(env) instead of RISCV_CPU(env_cpu(env)) macro.
> +    uint32_t pmu_avail_ctrs = cpu->pmu_avail_ctrs;
>       int ctr_index;
>       int base_csrno = CSR_MHPMCOUNTER3;
>   
> @@ -191,7 +192,7 @@ static RISCVException mctr(CPURISCVState *env, int csrno)
>           base_csrno += 0x80;
>       }
>       ctr_index = csrno - base_csrno;
> -    if (!pmu_num || ctr_index >= pmu_num) {
> +    if ((BIT(ctr_index) & pmu_avail_ctrs >> 3) == 0) {

Otherwise,

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

>           /* The PMU is not enabled or counter is out of range */
>           return RISCV_EXCP_ILLEGAL_INST;
>       }