On Mon, Dec 18, 2023 at 10:58 PM Daniel Henrique Barboza
<dbarb...@ventanamicro.com> wrote:
>
> We'll add a new bare CPU type that won't have any default priv_ver. This
> means that the CPU will default to priv_ver = 0, i.e. 1.10.0.
>
> At the same we'll allow these CPUs to enable extensions at will, but
> then, if the extension has a priv_ver newer than 1.10, we'll end up
> disabling it. Users will then need to manually set priv_ver to something
> other than 1.10 to enable the extensions they want, which is not ideal.
>
> Change the setter() of extensions to allow user enabled extensions to
> bump the priv_ver of the CPU. This will make it convenient for users to
> enable extensions for CPUs that doesn't set a default priv_ver.
>
> This change does not affect any existing CPU: vendor CPUs does not allow
> extensions to be enabled, and generic CPUs are already set to priv_ver
> LATEST.
>
> Signed-off-by: Daniel Henrique Barboza <dbarb...@ventanamicro.com>
> Reviewed-by: Andrew Jones <ajo...@ventanamicro.com>

Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>

Alistair

> ---
>  target/riscv/tcg/tcg-cpu.c | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
>
> diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
> index 7670120673..aee98db6f8 100644
> --- a/target/riscv/tcg/tcg-cpu.c
> +++ b/target/riscv/tcg/tcg-cpu.c
> @@ -114,6 +114,26 @@ static int cpu_cfg_ext_get_min_version(uint32_t 
> ext_offset)
>      g_assert_not_reached();
>  }
>
> +static void cpu_bump_multi_ext_priv_ver(CPURISCVState *env,
> +                                        uint32_t ext_offset)
> +{
> +    int ext_priv_ver;
> +
> +    if (env->priv_ver == PRIV_VERSION_LATEST) {
> +        return;
> +    }
> +
> +    ext_priv_ver = cpu_cfg_ext_get_min_version(ext_offset);
> +
> +    if (env->priv_ver < ext_priv_ver) {
> +        /*
> +         * Note: the 'priv_spec' command line option, if present,
> +         * will take precedence over this priv_ver bump.
> +         */
> +        env->priv_ver = ext_priv_ver;
> +    }
> +}
> +
>  static void cpu_cfg_ext_auto_update(RISCVCPU *cpu, uint32_t ext_offset,
>                                      bool value)
>  {
> @@ -757,6 +777,14 @@ static void cpu_set_misa_ext_cfg(Object *obj, Visitor 
> *v, const char *name,
>              return;
>          }
>
> +        if (misa_bit == RVH && env->priv_ver < PRIV_VERSION_1_12_0) {
> +            /*
> +             * Note: the 'priv_spec' command line option, if present,
> +             * will take precedence over this priv_ver bump.
> +             */
> +            env->priv_ver = PRIV_VERSION_1_12_0;
> +        }
> +
>          env->misa_ext |= misa_bit;
>          env->misa_ext_mask |= misa_bit;
>      } else {
> @@ -886,6 +914,10 @@ static void cpu_set_multi_ext_cfg(Object *obj, Visitor 
> *v, const char *name,
>          return;
>      }
>
> +    if (value) {
> +        cpu_bump_multi_ext_priv_ver(&cpu->env, multi_ext_cfg->offset);
> +    }
> +
>      isa_ext_update_enabled(cpu, multi_ext_cfg->offset, value);
>  }
>
> --
> 2.43.0
>
>

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