Re: [PATCH v5 60/60] target/riscv: configure and turn on vector extension from command line

[Alistair Francis]

On Thu, Mar 12, 2020 at 10:00 AM LIU Zhiwei <address@hidden> wrote:
>
> Vector extension is default off. The only way to use vector extension is
> 1. use cpu rv32 or rv64
> 2. turn on it by command line
> "-cpu rv64,v=true,vlen=128,elen=64,vext_spec=v0.7.1".
>
> vlen is the vector register length, default value is 128 bit.
> elen is the max operator size in bits, default value is 64 bit.
> vext_spec is the vector specification version, default value is v0.7.1.
> These properties can be specified with other values.
>
> Signed-off-by: LIU Zhiwei <address@hidden>
> ---
>  target/riscv/cpu.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
>  target/riscv/cpu.h |  2 ++
>  2 files changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 6e4135583d..5f1cdd4f2b 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -395,7 +395,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error 
> **errp)
>      }
>
>      set_priv_version(env, priv_version);
> -    set_vext_version(env, vext_version);
>      set_resetvec(env, DEFAULT_RSTVEC);
>
>      if (cpu->cfg.mmu) {
> @@ -463,6 +462,45 @@ static void riscv_cpu_realize(DeviceState *dev, Error 
> **errp)
>          if (cpu->cfg.ext_h) {
>              target_misa |= RVH;
>          }
> +        if (cpu->cfg.ext_v) {
> +            target_misa |= RVV;
> +            if (!is_power_of_2(cpu->cfg.vlen)) {
> +                error_setg(errp,
> +                        "Vector extension VLEN must be power of 2");
> +                return;
> +            }
> +            if (cpu->cfg.vlen > RV_VLEN_MAX || cpu->cfg.vlen < 128) {
> +                error_setg(errp,
> +                        "Vector extension implementation only supports VLEN "
> +                        "in the range [128, %d]", RV_VLEN_MAX);
> +                return;
> +            }
> +            if (!is_power_of_2(cpu->cfg.elen)) {
> +                error_setg(errp,
> +                        "Vector extension ELEN must be power of 2");
> +                return;
> +            }
> +            if (cpu->cfg.elen > 64 || cpu->cfg.vlen < 8) {
> +                error_setg(errp,
> +                        "Vector extension implementation only supports ELEN "
> +                        "in the range [8, 64]");
> +                return;
> +            }
> +            if (cpu->cfg.vext_spec) {
> +                if (!g_strcmp0(cpu->cfg.vext_spec, "v0.7.1")) {
> +                    vext_version = VEXT_VERSION_0_07_1;
> +                } else {
> +                    error_setg(errp,
> +                           "Unsupported vector spec version '%s'",
> +                           cpu->cfg.vext_spec);
> +                    return;
> +                }
> +            } else {
> +                qemu_log("vector verison is not specified, "
> +                        "use the default value v0.7.1\n");
> +            }
> +            set_vext_version(env, vext_version);
> +        }
>
>          set_misa(env, RVXLEN | target_misa);
>      }
> @@ -500,10 +538,14 @@ static Property riscv_cpu_properties[] = {
>      DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
>      /* This is experimental so mark with 'x-' */
>      DEFINE_PROP_BOOL("x-h", RISCVCPU, cfg.ext_h, false),
> +    DEFINE_PROP_BOOL("v", RISCVCPU, cfg.ext_v, false),

This should be x-v as it's experimental.

Alistair

>      DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
>      DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
>      DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
>      DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
> +    DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
> +    DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
> +    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_END_OF_LIST(),
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index e069e55e81..36ead8d6d5 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -285,12 +285,14 @@ typedef struct RISCVCPU {
>          bool ext_s;
>          bool ext_u;
>          bool ext_h;
> +        bool ext_v;
>          bool ext_counters;
>          bool ext_ifencei;
>          bool ext_icsr;
>
>          char *priv_spec;
>          char *user_spec;
> +        char *vext_spec;
>          uint16_t vlen;
>          uint16_t elen;
>          bool mmu;
> --
> 2.23.0
>