Re: [PATCH 3/4] target/riscv: Support MSTATUS.MPV/GVA only when RVH is enabled

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

On 2023/6/12 11:16, Weiwei Li wrote:
>
> On 2023/6/12 11:08, LIU Zhiwei wrote:
>>
>> On 2023/5/29 20:17, Weiwei Li wrote:
>>> MPV and GVA bits are added by hypervisor extension to mstatus
>>> and mstatush (if MXLEN=32).
>>
>> Have you found the CSR field specifications for them, especially for 
>> GVA.
>
> Yeah.  in the section 9.4.1 of the privilege spec:
>
> "/The hypervisor extension adds two fields, MPV and GVA, to the 
> machine-level mstatus or mstatush CSR/".

I mean the WARL or other CSR field specifications here.

Zhiwei

>
> Regards,
>
> Weiwei Li
>
>>
>> Zhiwei
>>
>>>
>>> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
>>> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
>>> ---
>>>   target/riscv/csr.c | 10 ++++------
>>>   1 file changed, 4 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
>>> index 58499b5afc..6ac11d1f11 100644
>>> --- a/target/riscv/csr.c
>>> +++ b/target/riscv/csr.c
>>> @@ -1311,11 +1311,9 @@ static RISCVException 
>>> write_mstatus(CPURISCVState *env, int csrno,
>>>       }
>>>         if (xl != MXL_RV32 || env->debugger) {
>>> -        /*
>>> -         * RV32: MPV and GVA are not in mstatus. The current plan 
>>> is to
>>> -         * add them to mstatush. For now, we just don't support it.
>>> -         */
>>> -        mask |= MSTATUS_MPV | MSTATUS_GVA;
>>> +        if (riscv_has_ext(env, RVH)) {
>>> +            mask |= MSTATUS_MPV | MSTATUS_GVA;
>>> +        }
>>>           if ((val & MSTATUS64_UXL) != 0) {
>>>               mask |= MSTATUS64_UXL;
>>>           }
>>> @@ -1351,7 +1349,7 @@ static RISCVException 
>>> write_mstatush(CPURISCVState *env, int csrno,
>>>                                        target_ulong val)
>>>   {
>>>       uint64_t valh = (uint64_t)val << 32;
>>> -    uint64_t mask = MSTATUS_MPV | MSTATUS_GVA;
>>> +    uint64_t mask = riscv_has_ext(env, RVH) ? MSTATUS_MPV | 
>>> MSTATUS_GVA : 0;
>>>         env->mstatus = (env->mstatus & ~mask) | (valh & mask);