Re: [PATCH v11 3/5] target/riscv: generate virtual instruction exception

[Alistair Francis <alistair23@gmail.com>]

On Sun, Oct 16, 2022 at 10:58 PM Mayuresh Chitale
<mchitale@ventanamicro.com> wrote:
>
> This patch adds a mechanism to generate a virtual instruction
> instruction exception instead of an illegal instruction exception
> during instruction decode when virt is enabled.
>
> Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>

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

Alistair

> ---
>  target/riscv/translate.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index db123da5ec..8b0bd38bb2 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -76,6 +76,7 @@ typedef struct DisasContext {
>         to reset this known value.  */
>      int frm;
>      RISCVMXL ol;
> +    bool virt_inst_excp;
>      bool virt_enabled;
>      const RISCVCPUConfig *cfg_ptr;
>      bool hlsx;
> @@ -243,7 +244,11 @@ static void gen_exception_illegal(DisasContext *ctx)
>  {
>      tcg_gen_st_i32(tcg_constant_i32(ctx->opcode), cpu_env,
>                     offsetof(CPURISCVState, bins));
> -    generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
> +    if (ctx->virt_inst_excp) {
> +        generate_exception(ctx, RISCV_EXCP_VIRT_INSTRUCTION_FAULT);
> +    } else {
> +        generate_exception(ctx, RISCV_EXCP_ILLEGAL_INST);
> +    }
>  }
>
>  static void gen_exception_inst_addr_mis(DisasContext *ctx)
> @@ -1062,6 +1067,7 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
>          { has_XVentanaCondOps_p,  decode_XVentanaCodeOps },
>      };
>
> +    ctx->virt_inst_excp = false;
>      /* Check for compressed insn */
>      if (insn_len(opcode) == 2) {
>          if (!has_ext(ctx, RVC)) {
> --
> 2.25.1
>
>