Re: [PATCH] target/riscv: Fix itrigger when icount is used

[Alistair Francis <alistair23@gmail.com>]

On Sat, Mar 25, 2023 at 2:04 AM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> When I boot a ubuntu image, QEMU output a "Bad icount read" message and exit.
> The reason is that when execute helper_mret or helper_sret, it will
> cause a call to icount_get_raw_locked (), which needs set can_do_io flag
> on cpustate.
>
> Thus we setting this flag when execute these two instructions.
>
> Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

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

Alistair

> ---
>  target/riscv/insn_trans/trans_privileged.c.inc | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/target/riscv/insn_trans/trans_privileged.c.inc b/target/riscv/insn_trans/trans_privileged.c.inc
> index 59501b2780..e3bee971c6 100644
> --- a/target/riscv/insn_trans/trans_privileged.c.inc
> +++ b/target/riscv/insn_trans/trans_privileged.c.inc
> @@ -77,6 +77,9 @@ static bool trans_sret(DisasContext *ctx, arg_sret *a)
>  #ifndef CONFIG_USER_ONLY
>      if (has_ext(ctx, RVS)) {
>          decode_save_opc(ctx);
> +        if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
> +            gen_io_start();
> +        }
>          gen_helper_sret(cpu_pc, cpu_env);
>          exit_tb(ctx); /* no chaining */
>          ctx->base.is_jmp = DISAS_NORETURN;
> @@ -93,6 +96,9 @@ static bool trans_mret(DisasContext *ctx, arg_mret *a)
>  {
>  #ifndef CONFIG_USER_ONLY
>      decode_save_opc(ctx);
> +    if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) {
> +        gen_io_start();
> +    }
>      gen_helper_mret(cpu_pc, cpu_env);
>      exit_tb(ctx); /* no chaining */
>      ctx->base.is_jmp = DISAS_NORETURN;
> --
> 2.17.1
>
>