Re: [PATCH v11 4/5] target/riscv: smstateen check for fcsr

[Mayuresh Chitale]

On Fri, Mar 24, 2023 at 7:01 PM liweiwei <liweiwei@iscas.ac.cn> wrote:
>
>
> On 2022/11/21 07:35, Alistair Francis wrote:
> > On Sun, Oct 16, 2022 at 11:09 PM Mayuresh Chitale
> > <mchitale@ventanamicro.com> wrote:
> >> If smstateen is implemented and sstateen0.fcsr is clear then the floating 
> >> point
> >> operations must return illegal instruction exception or virtual instruction
> >> trap, if relevant.
> >>
> >> Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
> >> Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
> >> ---
> >>   target/riscv/csr.c                        | 23 ++++++++++++
> >>   target/riscv/insn_trans/trans_rvf.c.inc   | 43 +++++++++++++++++++++--
> >>   target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
> >>   3 files changed, 75 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> >> index 71236f2b5d..8b25f885ec 100644
> >> --- a/target/riscv/csr.c
> >> +++ b/target/riscv/csr.c
> >> @@ -84,6 +84,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
> >>           !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
> >>           return RISCV_EXCP_ILLEGAL_INST;
> >>       }
> >> +
> >> +    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
> >> +        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
> >> +    }
> >>   #endif
> >>       return RISCV_EXCP_NONE;
> >>   }
> >> @@ -2023,6 +2027,9 @@ static RISCVException write_mstateen0(CPURISCVState 
> >> *env, int csrno,
> >>                                         target_ulong new_val)
> >>   {
> >>       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >> +    if (!riscv_has_ext(env, RVF)) {
> >> +        wr_mask |= SMSTATEEN0_FCSR;
> >> +    }
> >>
> >>       return write_mstateen(env, csrno, wr_mask, new_val);
> >>   }
> >> @@ -2059,6 +2066,10 @@ static RISCVException 
> >> write_mstateen0h(CPURISCVState *env, int csrno,
> >>   {
> >>       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >>
> >> +    if (!riscv_has_ext(env, RVF)) {
> >> +        wr_mask |= SMSTATEEN0_FCSR;
> >> +    }
> >> +
> >>       return write_mstateenh(env, csrno, wr_mask, new_val);
> >>   }
> >>
> >> @@ -2096,6 +2107,10 @@ static RISCVException write_hstateen0(CPURISCVState 
> >> *env, int csrno,
> >>   {
> >>       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >>
> >> +    if (!riscv_has_ext(env, RVF)) {
> >> +        wr_mask |= SMSTATEEN0_FCSR;
> >> +    }
> >> +
> >>       return write_hstateen(env, csrno, wr_mask, new_val);
> >>   }
> >>
> >> @@ -2135,6 +2150,10 @@ static RISCVException 
> >> write_hstateen0h(CPURISCVState *env, int csrno,
> >>   {
> >>       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >>
> >> +    if (!riscv_has_ext(env, RVF)) {
> >> +        wr_mask |= SMSTATEEN0_FCSR;
> >> +    }
> >> +
> >>       return write_hstateenh(env, csrno, wr_mask, new_val);
> >>   }
> >>
> >> @@ -2182,6 +2201,10 @@ static RISCVException write_sstateen0(CPURISCVState 
> >> *env, int csrno,
> >>   {
> >>       uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
> >>
> >> +    if (!riscv_has_ext(env, RVF)) {
> >> +        wr_mask |= SMSTATEEN0_FCSR;
> >> +    }
> >> +
> >>       return write_sstateen(env, csrno, wr_mask, new_val);
> >>   }
> >>
> >> diff --git a/target/riscv/insn_trans/trans_rvf.c.inc 
> >> b/target/riscv/insn_trans/trans_rvf.c.inc
> >> index a1d3eb52ad..93657680c6 100644
> >> --- a/target/riscv/insn_trans/trans_rvf.c.inc
> >> +++ b/target/riscv/insn_trans/trans_rvf.c.inc
> >> @@ -24,9 +24,46 @@
> >>               return false; \
> >>   } while (0)
> >>
> >> -#define REQUIRE_ZFINX_OR_F(ctx) do {\
> >> -    if (!ctx->cfg_ptr->ext_zfinx) { \
> >> -        REQUIRE_EXT(ctx, RVF); \
> >> +#ifndef CONFIG_USER_ONLY
> >> +static inline bool smstateen_fcsr_check(DisasContext *ctx, int index)
> >> +{
> >> +    CPUState *cpu = ctx->cs;
> >> +    CPURISCVState *env = cpu->env_ptr;
> >> +    uint64_t stateen = env->mstateen[index];
> > Sorry I missed this the first time around. You can't access env here
> >
> > Richard pointed it out here:
> > https://patchwork.kernel.org/project/qemu-devel/patch/20221117070316.58447-8-liweiwei@iscas.ac.cn/#25095773
> >
> > I'm going to drop this patch and patch v5
> >
> > Alistair
>
> Hi, Any new updates for the last two patches after they were dropped?
>
> Regards,
>
> Weiwei Li
>
Looks like I missed the original comments from Richard and Alistair. I
am not yet clear how to implement it but I am looking into it.