Re: [PATCH v4 35/41] target/riscv: Make riscv_cpu_tlb_fill sysemu only

[Alistair Francis]

On Thu, Oct 7, 2021 at 4:12 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The fallback code in cpu_loop_exit_sigsegv is sufficient
> for riscv linux-user.
>
> Remove the code from cpu_loop that raised SIGSEGV.
>
> Cc: qemu-riscv@nongnu.org
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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

Alistair

> ---
>  linux-user/riscv/cpu_loop.c |  7 -------
>  target/riscv/cpu.c          |  2 +-
>  target/riscv/cpu_helper.c   | 21 +--------------------
>  3 files changed, 2 insertions(+), 28 deletions(-)
>
> diff --git a/linux-user/riscv/cpu_loop.c b/linux-user/riscv/cpu_loop.c
> index 9859a366e4..aef019b1c8 100644
> --- a/linux-user/riscv/cpu_loop.c
> +++ b/linux-user/riscv/cpu_loop.c
> @@ -87,13 +87,6 @@ void cpu_loop(CPURISCVState *env)
>              sigcode = TARGET_TRAP_BRKPT;
>              sigaddr = env->pc;
>              break;
> -        case RISCV_EXCP_INST_PAGE_FAULT:
> -        case RISCV_EXCP_LOAD_PAGE_FAULT:
> -        case RISCV_EXCP_STORE_PAGE_FAULT:
> -            signum = TARGET_SIGSEGV;
> -            sigcode = TARGET_SEGV_MAPERR;
> -            sigaddr = env->badaddr;
> -            break;
>          case RISCV_EXCP_SEMIHOST:
>              env->gpr[xA0] = do_common_semihosting(cs);
>              env->pc += 4;
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 7c626d89cd..0292a72feb 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -675,9 +675,9 @@ static const struct SysemuCPUOps riscv_sysemu_ops = {
>  static const struct TCGCPUOps riscv_tcg_ops = {
>      .initialize = riscv_translate_init,
>      .synchronize_from_tb = riscv_cpu_synchronize_from_tb,
> -    .tlb_fill = riscv_cpu_tlb_fill,
>
>  #ifndef CONFIG_USER_ONLY
> +    .tlb_fill = riscv_cpu_tlb_fill,
>      .cpu_exec_interrupt = riscv_cpu_exec_interrupt,
>      .do_interrupt = riscv_cpu_do_interrupt,
>      .do_transaction_failed = riscv_cpu_do_transaction_failed,
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index d41d5cd27c..b520d6fc78 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -748,7 +748,6 @@ void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr 
> addr,
>                              riscv_cpu_two_stage_lookup(mmu_idx);
>      riscv_raise_exception(env, cs->exception_index, retaddr);
>  }
> -#endif /* !CONFIG_USER_ONLY */
>
>  bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
>                          MMUAccessType access_type, int mmu_idx,
> @@ -756,7 +755,6 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int 
> size,
>  {
>      RISCVCPU *cpu = RISCV_CPU(cs);
>      CPURISCVState *env = &cpu->env;
> -#ifndef CONFIG_USER_ONLY
>      vaddr im_address;
>      hwaddr pa = 0;
>      int prot, prot2, prot_pmp;
> @@ -888,25 +886,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int 
> size,
>      }
>
>      return true;
> -
> -#else
> -    switch (access_type) {
> -    case MMU_INST_FETCH:
> -        cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
> -        break;
> -    case MMU_DATA_LOAD:
> -        cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
> -        break;
> -    case MMU_DATA_STORE:
> -        cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
> -        break;
> -    default:
> -        g_assert_not_reached();
> -    }
> -    env->badaddr = address;
> -    cpu_loop_exit_restore(cs, retaddr);
> -#endif
>  }
> +#endif /* !CONFIG_USER_ONLY */
>
>  /*
>   * Handle Traps
> --
> 2.25.1
>
>