Re: [PATCH 1/1] Add Zihintpause support

[Dao Lu]

Thanks Richard! I have fixed it following your advice:

diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
index 528c30c9a2..acd2548e9b 100644
--- a/target/riscv/insn_trans/trans_rvi.c.inc
+++ b/target/riscv/insn_trans/trans_rvi.c.inc
@@ -808,9 +808,13 @@ static bool trans_pause(DisasContext *ctx, arg_pause *a)

     /*
      * PAUSE is a no-op in QEMU,
-     * however we need to clear the reservation
+     * however we need to clear the reservation,
+     * end the TB and return to main loop
      */
     tcg_gen_movi_tl(load_res, -1);
+    gen_set_pc_imm(ctx, ctx->pc_succ_insn);
+    tcg_gen_exit_tb(NULL, 0);
+    ctx->base.is_jmp = DISAS_NORETURN;

     return true;
 }

I will wait a bit to see if there are any more comments.

On Tue, May 10, 2022 at 8:43 AM Richard Henderson <richard.henderson@linaro.org> wrote:

On 5/9/22 23:42, Dao Lu wrote:
> +static bool trans_pause(DisasContext *ctx, arg_pause *a)
> +{
> +    REQUIRE_ZIHINTPAUSE(ctx);
> +
> +    /*
> +     * PAUSE is a no-op in QEMU,
> +     * however we need to clear the reservation
> +     */
> +    tcg_gen_movi_tl(load_res, -1);

I recommend ending the TB and returning to the main loop.  When running in round-robin
mode, this will yield to the next cpu.


r~