Re: [PATCH] target/riscv: Exit current TB after an sfence.vma

[Alistair Francis]

On Wed, Mar 16, 2022 at 5:26 AM Idan Horowitz <idan.horowitz@gmail.com> wrote:
>
> If the pages which control the translation of the currently executing
> instructions are changed, and then the TLB is flushed using sfence.vma
> we have to exit the current TB early, to ensure we don't execute stale
> instructions.
>
> Signed-off-by: Idan Horowitz <idan.horowitz@gmail.com>

Thanks!

Applied to riscv-to-apply.next

Alistair

> ---
>  target/riscv/insn_trans/trans_privileged.c.inc | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/target/riscv/insn_trans/trans_privileged.c.inc 
> b/target/riscv/insn_trans/trans_privileged.c.inc
> index 53613682e8..f265e8202d 100644
> --- a/target/riscv/insn_trans/trans_privileged.c.inc
> +++ b/target/riscv/insn_trans/trans_privileged.c.inc
> @@ -114,6 +114,13 @@ static bool trans_sfence_vma(DisasContext *ctx, 
> arg_sfence_vma *a)
>  {
>  #ifndef CONFIG_USER_ONLY
>      gen_helper_tlb_flush(cpu_env);
> +    /*
> +     * The flush might have changed the backing physical memory of
> +     * the instructions we're currently executing
> +     */
> +    gen_set_pc_imm(ctx, ctx->pc_succ_insn);
> +    tcg_gen_exit_tb(NULL, 0);
> +    ctx->base.is_jmp = DISAS_NORETURN;
>      return true;
>  #endif
>      return false;
> --
> 2.35.1
>
>