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[PATCH v9 3/4] target/riscv: smstateen check for fcsr

Mayuresh Chitale posted 4 patches 3 years, 4 months ago
Maintainers: Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>
There is a newer version of this series
[PATCH v9 3/4] target/riscv: smstateen check for fcsr
Posted by Mayuresh Chitale 3 years, 4 months ago 
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>
---
 target/riscv/csr.c                        | 23 +++++++++++++
 target/riscv/insn_trans/trans_rvf.c.inc   | 40 +++++++++++++++++++++--
 target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
 3 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 59d5aa74ee..edaecf53ce 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;
 }
@@ -2024,6 +2028,9 @@ 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);
 }
@@ -2072,6 +2079,10 @@ 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);
 }
 
@@ -2121,6 +2132,10 @@ 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);
 }
 
@@ -2172,6 +2187,10 @@ 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);
 }
 
@@ -2231,6 +2250,10 @@ 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..ce8a0cc34b 100644
--- a/target/riscv/insn_trans/trans_rvf.c.inc
+++ b/target/riscv/insn_trans/trans_rvf.c.inc
@@ -24,9 +24,43 @@
             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_check(DisasContext *ctx, int index)
+{
+    CPUState *cpu = ctx->cs;
+    CPURISCVState *env = cpu->env_ptr;
+    uint64_t stateen = env->mstateen[index];
+
+    if (!ctx->cfg_ptr->ext_smstateen || env->priv == PRV_M) {
+        return true;
+    }
+
+    if (ctx->virt_enabled) {
+        stateen &= env->hstateen[index];
+    }
+
+    if (env->priv == PRV_U && has_ext(ctx, RVS)) {
+        stateen &= env->sstateen[index];
+    }
+
+    if (!(stateen & SMSTATEEN0_FCSR)) {
+        return false;
+    }
+
+    return true;
+}
+#else
+#define smstateen_check(ctx, index) (true)
+#endif
+
+#define REQUIRE_ZFINX_OR_F(ctx) do { \
+    if (!has_ext(ctx, RVF)) { \
+        if (!ctx->cfg_ptr->ext_zfinx) { \
+            return false; \
+        } \
+        if (!smstateen_check(ctx, 0)) { \
+            return false; \
+        } \
     } \
 } while (0)
 
diff --git a/target/riscv/insn_trans/trans_rvzfh.c.inc b/target/riscv/insn_trans/trans_rvzfh.c.inc
index 5d07150cd0..44d962c920 100644
--- a/target/riscv/insn_trans/trans_rvzfh.c.inc
+++ b/target/riscv/insn_trans/trans_rvzfh.c.inc
@@ -20,18 +20,27 @@
     if (!ctx->cfg_ptr->ext_zfh) {      \
         return false;         \
     }                         \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZHINX_OR_ZFH(ctx) do { \
     if (!ctx->cfg_ptr->ext_zhinx && !ctx->cfg_ptr->ext_zfh) { \
         return false;                  \
     }                                  \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN(ctx) do {       \
     if (!(ctx->cfg_ptr->ext_zfh || ctx->cfg_ptr->ext_zfhmin)) { \
         return false;                         \
     }                                         \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN_OR_ZHINX_OR_ZHINXMIN(ctx) do { \
@@ -39,6 +48,9 @@
           ctx->cfg_ptr->ext_zhinx || ctx->cfg_ptr->ext_zhinxmin)) {     \
         return false;                                        \
     }                                                        \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 static bool trans_flh(DisasContext *ctx, arg_flh *a)
-- 
2.25.1
Re: [PATCH v9 3/4] target/riscv: smstateen check for fcsr
Posted by weiwei 3 years, 4 months ago 
On 2022/9/19 14:29, Mayuresh Chitale 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>
> ---
>   target/riscv/csr.c                        | 23 +++++++++++++
>   target/riscv/insn_trans/trans_rvf.c.inc   | 40 +++++++++++++++++++++--
>   target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
>   3 files changed, 72 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 59d5aa74ee..edaecf53ce 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;
>   }
> @@ -2024,6 +2028,9 @@ 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);
>   }
> @@ -2072,6 +2079,10 @@ 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);
>   }
>   
> @@ -2121,6 +2132,10 @@ 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);
>   }
>   
> @@ -2172,6 +2187,10 @@ 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);
>   }
>   
> @@ -2231,6 +2250,10 @@ 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..ce8a0cc34b 100644
> --- a/target/riscv/insn_trans/trans_rvf.c.inc
> +++ b/target/riscv/insn_trans/trans_rvf.c.inc
> @@ -24,9 +24,43 @@
>               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_check(DisasContext *ctx, int index)
> +{
> +    CPUState *cpu = ctx->cs;
> +    CPURISCVState *env = cpu->env_ptr;
> +    uint64_t stateen = env->mstateen[index];
> +
> +    if (!ctx->cfg_ptr->ext_smstateen || env->priv == PRV_M) {
> +        return true;
> +    }
> +
> +    if (ctx->virt_enabled) {
> +        stateen &= env->hstateen[index];
> +    }
> +
> +    if (env->priv == PRV_U && has_ext(ctx, RVS)) {
> +        stateen &= env->sstateen[index];
> +    }
> +
> +    if (!(stateen & SMSTATEEN0_FCSR)) {
> +        return false;
> +    }
> +
> +    return true;
> +}
> +#else
> +#define smstateen_check(ctx, index) (true)
> +#endif
> +
> +#define REQUIRE_ZFINX_OR_F(ctx) do { \
> +    if (!has_ext(ctx, RVF)) { \
> +        if (!ctx->cfg_ptr->ext_zfinx) { \
> +            return false; \
> +        } \
> +        if (!smstateen_check(ctx, 0)) { \
> +            return false; \
> +        } \
>       } \
>   } while (0)

I think the potential exception triggered by smstateen_check is not 
correct here:

"return false"  can only trigger illegal instruction exception.

However, smstateen_check  is for accessing fcsr CSR, It may trigger 
illegal or  virtual instruction exception

based on the privilege mode and Xstateen CSRs.

Regards,

Weiwei Li

>   
> diff --git a/target/riscv/insn_trans/trans_rvzfh.c.inc b/target/riscv/insn_trans/trans_rvzfh.c.inc
> index 5d07150cd0..44d962c920 100644
> --- a/target/riscv/insn_trans/trans_rvzfh.c.inc
> +++ b/target/riscv/insn_trans/trans_rvzfh.c.inc
> @@ -20,18 +20,27 @@
>       if (!ctx->cfg_ptr->ext_zfh) {      \
>           return false;         \
>       }                         \
> +    if (!smstateen_check(ctx, 0)) { \
> +        return false; \
> +    } \
>   } while (0)
>   
>   #define REQUIRE_ZHINX_OR_ZFH(ctx) do { \
>       if (!ctx->cfg_ptr->ext_zhinx && !ctx->cfg_ptr->ext_zfh) { \
>           return false;                  \
>       }                                  \
> +    if (!smstateen_check(ctx, 0)) { \
> +        return false; \
> +    } \
>   } while (0)
>   
>   #define REQUIRE_ZFH_OR_ZFHMIN(ctx) do {       \
>       if (!(ctx->cfg_ptr->ext_zfh || ctx->cfg_ptr->ext_zfhmin)) { \
>           return false;                         \
>       }                                         \
> +    if (!smstateen_check(ctx, 0)) { \
> +        return false; \
> +    } \
>   } while (0)
>   
>   #define REQUIRE_ZFH_OR_ZFHMIN_OR_ZHINX_OR_ZHINXMIN(ctx) do { \
> @@ -39,6 +48,9 @@
>             ctx->cfg_ptr->ext_zhinx || ctx->cfg_ptr->ext_zhinxmin)) {     \
>           return false;                                        \
>       }                                                        \
> +    if (!smstateen_check(ctx, 0)) { \
> +        return false; \
> +    } \
>   } while (0)
>   
>   static bool trans_flh(DisasContext *ctx, arg_flh *a)
Re: [PATCH v9 3/4] target/riscv: smstateen check for fcsr
Posted by mchitale@ventanamicro.com 3 years, 4 months ago 
On Thu, 2022-09-29 at 09:09 +0800, weiwei wrote:
> On 2022/9/19 14:29, Mayuresh Chitale 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>
> > ---
> >   target/riscv/csr.c                        | 23 +++++++++++++
> >   target/riscv/insn_trans/trans_rvf.c.inc   | 40
> > +++++++++++++++++++++--
> >   target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
> >   3 files changed, 72 insertions(+), 3 deletions(-)
> > 
> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > index 59d5aa74ee..edaecf53ce 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;
> >   }
> > @@ -2024,6 +2028,9 @@ 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);
> >   }
> > @@ -2072,6 +2079,10 @@ 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);
> >   }
> >   
> > @@ -2121,6 +2132,10 @@ 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);
> >   }
> >   
> > @@ -2172,6 +2187,10 @@ 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);
> >   }
> >   
> > @@ -2231,6 +2250,10 @@ 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..ce8a0cc34b 100644
> > --- a/target/riscv/insn_trans/trans_rvf.c.inc
> > +++ b/target/riscv/insn_trans/trans_rvf.c.inc
> > @@ -24,9 +24,43 @@
> >               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_check(DisasContext *ctx, int index)
> > +{
> > +    CPUState *cpu = ctx->cs;
> > +    CPURISCVState *env = cpu->env_ptr;
> > +    uint64_t stateen = env->mstateen[index];
> > +
> > +    if (!ctx->cfg_ptr->ext_smstateen || env->priv == PRV_M) {
> > +        return true;
> > +    }
> > +
> > +    if (ctx->virt_enabled) {
> > +        stateen &= env->hstateen[index];
> > +    }
> > +
> > +    if (env->priv == PRV_U && has_ext(ctx, RVS)) {
> > +        stateen &= env->sstateen[index];
> > +    }
> > +
> > +    if (!(stateen & SMSTATEEN0_FCSR)) {
> > +        return false;
> > +    }
> > +
> > +    return true;
> > +}
> > +#else
> > +#define smstateen_check(ctx, index) (true)
> > +#endif
> > +
> > +#define REQUIRE_ZFINX_OR_F(ctx) do { \
> > +    if (!has_ext(ctx, RVF)) { \
> > +        if (!ctx->cfg_ptr->ext_zfinx) { \
> > +            return false; \
> > +        } \
> > +        if (!smstateen_check(ctx, 0)) { \
> > +            return false; \
> > +        } \
> >       } \
> >   } while (0)
> 
> I think the potential exception triggered by smstateen_check is not 
> correct here:
> 
> "return false"  can only trigger illegal instruction exception.
> 
> However, smstateen_check  is for accessing fcsr CSR, It may trigger 
> illegal or  virtual instruction exception
> 
> based on the privilege mode and Xstateen CSRs.
> 
> Regards,
> 
> Weiwei Li

Ok. Need to check on how to do it.
> 
> >   
> > diff --git a/target/riscv/insn_trans/trans_rvzfh.c.inc
> > b/target/riscv/insn_trans/trans_rvzfh.c.inc
> > index 5d07150cd0..44d962c920 100644
> > --- a/target/riscv/insn_trans/trans_rvzfh.c.inc
> > +++ b/target/riscv/insn_trans/trans_rvzfh.c.inc
> > @@ -20,18 +20,27 @@
> >       if (!ctx->cfg_ptr->ext_zfh) {      \
> >           return false;         \
> >       }                         \
> > +    if (!smstateen_check(ctx, 0)) { \
> > +        return false; \
> > +    } \
> >   } while (0)
> >   
> >   #define REQUIRE_ZHINX_OR_ZFH(ctx) do { \
> >       if (!ctx->cfg_ptr->ext_zhinx && !ctx->cfg_ptr->ext_zfh) { \
> >           return false;                  \
> >       }                                  \
> > +    if (!smstateen_check(ctx, 0)) { \
> > +        return false; \
> > +    } \
> >   } while (0)
> >   
> >   #define REQUIRE_ZFH_OR_ZFHMIN(ctx) do {       \
> >       if (!(ctx->cfg_ptr->ext_zfh || ctx->cfg_ptr->ext_zfhmin)) { \
> >           return false;                         \
> >       }                                         \
> > +    if (!smstateen_check(ctx, 0)) { \
> > +        return false; \
> > +    } \
> >   } while (0)
> >   
> >   #define REQUIRE_ZFH_OR_ZFHMIN_OR_ZHINX_OR_ZHINXMIN(ctx) do { \
> > @@ -39,6 +48,9 @@
> >             ctx->cfg_ptr->ext_zhinx || ctx->cfg_ptr->ext_zhinxmin)) 
> > {     \
> >           return false;                                        \
> >       }                                                        \
> > +    if (!smstateen_check(ctx, 0)) { \
> > +        return false; \
> > +    } \
> >   } while (0)
> >   
> >   static bool trans_flh(DisasContext *ctx, arg_flh *a)

Patchew 2.1-devel-b67e4c2

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