Re: [PATCH 2/4] target/riscv: Add CPU feature for AIA CSRs

[Alistair Francis]

On Sat, May 15, 2021 at 12:35 AM Anup Patel <anup.patel@wdc.com> wrote:
>
> We add experimental CPU feature to enable AIA CSRs. This experimental
> feature can be enabled by setting "x-aia=true" for CPU in the QEMU
> command-line parameters.
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> ---
>  target/riscv/cpu.c | 5 +++++
>  target/riscv/cpu.h | 4 +++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 7d6ed80f6b..f3702111ae 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -414,6 +414,10 @@ static void riscv_cpu_realize(DeviceState *dev, Error 
> **errp)
>          set_feature(env, RISCV_FEATURE_PMP);
>      }
>
> +    if (cpu->cfg.aia) {
> +        set_feature(env, RISCV_FEATURE_AIA);
> +    }
> +
>      set_resetvec(env, cpu->cfg.resetvec);
>
>      /* If only XLEN is set for misa, then set misa from properties */
> @@ -554,6 +558,7 @@ static Property riscv_cpu_properties[] = {
>      DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
>      DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
>      DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
> +    DEFINE_PROP_BOOL("x-aia", RISCVCPU, cfg.aia, false),

This line should be a seperate patch at the end of the series.

The idea is that we don't allow users to enable the feature until it
has been fully implemented.

Alistair

>      DEFINE_PROP_UINT64("resetvec", RISCVCPU, cfg.resetvec, DEFAULT_RSTVEC),
>      DEFINE_PROP_END_OF_LIST(),
>  };
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 0a33d387ba..f00c60c840 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -80,7 +80,8 @@
>  enum {
>      RISCV_FEATURE_MMU,
>      RISCV_FEATURE_PMP,
> -    RISCV_FEATURE_MISA
> +    RISCV_FEATURE_MISA,
> +    RISCV_FEATURE_AIA
>  };
>
>  #define PRIV_VERSION_1_10_0 0x00011000
> @@ -303,6 +304,7 @@ struct RISCVCPU {
>          uint16_t elen;
>          bool mmu;
>          bool pmp;
> +        bool aia;
>          uint64_t resetvec;
>      } cfg;
>  };
> --
> 2.25.1
>
>