Re: [PATCH v2 50/50] target/i386: Remove user-only i/o stubs

[Paolo Bonzini]

On 14/05/21 17:13, Richard Henderson wrote:
> With the previous patch for check_io, we now have enough for
> the compiler to dead-code eliminate all of the i/o helpers.
>
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

> ---
>   target/i386/helper.h              |  3 +-
>   target/i386/tcg/translate.c       |  6 ++++
>   target/i386/tcg/user/misc_stubs.c | 55 -------------------------------
>   target/i386/tcg/user/meson.build  |  1 -
>   4 files changed, 7 insertions(+), 58 deletions(-)
>   delete mode 100644 target/i386/tcg/user/misc_stubs.c
>
> diff --git a/target/i386/helper.h b/target/i386/helper.h
> index 3fd0253298..f3d8c3f949 100644
> --- a/target/i386/helper.h
> +++ b/target/i386/helper.h
> @@ -86,14 +86,13 @@ DEF_HELPER_1(rdtsc, void, env)
>   DEF_HELPER_1(rdtscp, void, env)
>   DEF_HELPER_FLAGS_1(rdpmc, TCG_CALL_NO_WG, noreturn, env)
>   
> +#ifndef CONFIG_USER_ONLY
>   DEF_HELPER_3(outb, void, env, i32, i32)
>   DEF_HELPER_2(inb, tl, env, i32)
>   DEF_HELPER_3(outw, void, env, i32, i32)
>   DEF_HELPER_2(inw, tl, env, i32)
>   DEF_HELPER_3(outl, void, env, i32, i32)
>   DEF_HELPER_2(inl, tl, env, i32)
> -
> -#ifndef CONFIG_USER_ONLY
>   DEF_HELPER_FLAGS_3(check_io, TCG_CALL_NO_WG, void, env, i32, i32)
>   DEF_HELPER_FLAGS_4(bpt_io, TCG_CALL_NO_WG, void, env, i32, i32, tl)
>   DEF_HELPER_2(svm_check_intercept, void, env, i32)
> diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
> index bcc642bf6e..08ff3fe232 100644
> --- a/target/i386/tcg/translate.c
> +++ b/target/i386/tcg/translate.c
> @@ -197,8 +197,14 @@ STUB_HELPER(check_io, TCGv_env env, TCGv_i32 port, 
> TCGv_i32 size)
>   STUB_HELPER(clgi, TCGv_env env)
>   STUB_HELPER(flush_page, TCGv_env env, TCGv addr)
>   STUB_HELPER(hlt, TCGv_env env, TCGv_i32 pc_ofs)
> +STUB_HELPER(inb, TCGv ret, TCGv_env env, TCGv_i32 port)
> +STUB_HELPER(inw, TCGv ret, TCGv_env env, TCGv_i32 port)
> +STUB_HELPER(inl, TCGv ret, TCGv_env env, TCGv_i32 port)
>   STUB_HELPER(monitor, TCGv_env env, TCGv addr)
>   STUB_HELPER(mwait, TCGv_env env, TCGv_i32 pc_ofs)
> +STUB_HELPER(outb, TCGv_env env, TCGv_i32 port, TCGv_i32 val)
> +STUB_HELPER(outw, TCGv_env env, TCGv_i32 port, TCGv_i32 val)
> +STUB_HELPER(outl, TCGv_env env, TCGv_i32 port, TCGv_i32 val)
>   STUB_HELPER(rdmsr, TCGv_env env)
>   STUB_HELPER(read_crN, TCGv ret, TCGv_env env, TCGv_i32 reg)
>   STUB_HELPER(set_dr, TCGv_env env, TCGv_i32 reg, TCGv val)
> diff --git a/target/i386/tcg/user/misc_stubs.c 
> b/target/i386/tcg/user/misc_stubs.c
> deleted file mode 100644
> index df38b44d6e..0000000000
> --- a/target/i386/tcg/user/misc_stubs.c
> +++ /dev/null
> @@ -1,55 +0,0 @@
> -/*
> - *  x86 misc helpers
> - *
> - *  Copyright (c) 2003 Fabrice Bellard
> - *
> - * This library is free software; you can redistribute it and/or
> - * modify it under the terms of the GNU Lesser General Public
> - * License as published by the Free Software Foundation; either
> - * version 2.1 of the License, or (at your option) any later version.
> - *
> - * This library is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> - * Lesser General Public License for more details.
> - *
> - * You should have received a copy of the GNU Lesser General Public
> - * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> - */
> -
> -#include "qemu/osdep.h"
> -#include "cpu.h"
> -#include "exec/helper-proto.h"
> -
> -void helper_outb(CPUX86State *env, uint32_t port, uint32_t data)
> -{
> -    g_assert_not_reached();
> -}
> -
> -target_ulong helper_inb(CPUX86State *env, uint32_t port)
> -{
> -    g_assert_not_reached();
> -    return 0;
> -}
> -
> -void helper_outw(CPUX86State *env, uint32_t port, uint32_t data)
> -{
> -    g_assert_not_reached();
> -}
> -
> -target_ulong helper_inw(CPUX86State *env, uint32_t port)
> -{
> -    g_assert_not_reached();
> -    return 0;
> -}
> -
> -void helper_outl(CPUX86State *env, uint32_t port, uint32_t data)
> -{
> -    g_assert_not_reached();
> -}
> -
> -target_ulong helper_inl(CPUX86State *env, uint32_t port)
> -{
> -    g_assert_not_reached();
> -    return 0;
> -}
> diff --git a/target/i386/tcg/user/meson.build b/target/i386/tcg/user/meson.build
> index 3555b15bdd..1df6bc4343 100644
> --- a/target/i386/tcg/user/meson.build
> +++ b/target/i386/tcg/user/meson.build
> @@ -1,5 +1,4 @@
>   i386_user_ss.add(when: ['CONFIG_TCG', 'CONFIG_USER_ONLY'], if_true: files(
>     'excp_helper.c',
> -  'misc_stubs.c',
>     'seg_helper.c',
>   ))