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From: "Alex Bennée" <alex.bennee@linaro.org>
To: Sergey Fedorov <sergey.fedorov@linaro.org>
Cc: qemu-devel@nongnu.org, Sergey Fedorov <serge.fdrv@gmail.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Peter Crosthwaite <crosthwaite.peter@gmail.com>,
	Richard Henderson <rth@twiddle.net>,
	Riku Voipio <riku.voipio@iki.fi>,
	Blue Swirl <blauwirbel@gmail.com>,
	Peter Maydell <peter.maydell@linaro.org>,
	"Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
	Eduardo Habkost <ehabkost@redhat.com>,
	Michael Walle <michael@walle.cc>,
	Aurelien Jarno <aurelien@aurel32.net>,
	Leon Alrae <leon.alrae@imgtec.com>,
	Anthony Green <green@moxielogic.com>, Jia Liu <proljc@gmail.com>,
	Alexander Graf <agraf@suse.de>,
	Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
	Bastian Koppelmann <kbastian@mail.uni-paderborn.de>,
	Guan Xuetao <gxt@mprc.pku.edu.cn>,
	Max Filippov <jcmvbkbc@gmail.com>,
	qemu-arm@nongnu.org, qemu-ppc@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v4 10/10] tcg: Allow goto_tb to any target PC in user mode
Date: Thu, 21 Apr 2016 15:42:03 +0100	[thread overview]
Message-ID: <87wpnrt45g.fsf@linaro.org> (raw)
In-Reply-To: <1461186921-14977-11-git-send-email-sergey.fedorov@linaro.org>


Sergey Fedorov <sergey.fedorov@linaro.org> writes:

> From: Sergey Fedorov <serge.fdrv@gmail.com>
>
> In user mode, there's only a static address translation, TBs are always
> invalidated properly and direct jumps are reset when mapping change.
> Thus the destination address is always valid for direct jumps and
> there's no need to restrict it to the pages the TB resides in.
>
> Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
> Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
> Cc: Riku Voipio <riku.voipio@iki.fi>
> Cc: Blue Swirl <blauwirbel@gmail.com>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>
> Changes in v4:
>  * Explanatory comments moved to tcg_gen_goto_tb()
>    declaration comment
>  * Cc'ed usermode maintainers in commit message excplicitly
>
>  target-alpha/translate.c      |  4 ++++
>  target-arm/translate-a64.c    |  2 ++
>  target-arm/translate.c        | 18 ++++++++++++------
>  target-cris/translate.c       | 18 ++++++++++++------
>  target-i386/translate.c       | 23 ++++++++++++++---------
>  target-lm32/translate.c       | 21 +++++++++++++++------
>  target-m68k/translate.c       | 18 ++++++++++++------
>  target-microblaze/translate.c | 15 +++++++++++----
>  target-mips/translate.c       | 20 +++++++++++++++-----
>  target-moxie/translate.c      | 21 +++++++++++++++------
>  target-openrisc/translate.c   | 20 +++++++++++++++-----
>  target-ppc/translate.c        | 20 +++++++++++++++-----
>  target-s390x/translate.c      | 17 +++++++++++------
>  target-sh4/translate.c        | 21 +++++++++++++++------
>  target-sparc/translate.c      | 24 +++++++++++++++++-------
>  target-tricore/translate.c    | 20 +++++++++++++++-----
>  target-unicore32/translate.c  | 16 +++++++++++-----
>  target-xtensa/translate.c     |  4 ++++
>  tcg/tcg-op.h                  |  9 ++++++---
>  19 files changed, 221 insertions(+), 90 deletions(-)
>
> diff --git a/target-alpha/translate.c b/target-alpha/translate.c
> index 5b86992dd367..d43b3f41bdd0 100644
> --- a/target-alpha/translate.c
> +++ b/target-alpha/translate.c
> @@ -464,8 +464,12 @@ static bool use_goto_tb(DisasContext *ctx, uint64_t dest)
>      if (in_superpage(ctx, dest)) {
>          return true;
>      }
> +#ifndef CONFIG_USER_ONLY
>      /* Check for the dest on the same page as the start of the TB.  */
>      return ((ctx->tb->pc ^ dest) & TARGET_PAGE_MASK) == 0;
> +#else
> +    return true;
> +#endif
>  }
>
>  static ExitStatus gen_bdirect(DisasContext *ctx, int ra, int32_t disp)
> diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
> index b13cff756ad1..476d677f22d7 100644
> --- a/target-arm/translate-a64.c
> +++ b/target-arm/translate-a64.c
> @@ -274,10 +274,12 @@ static inline bool use_goto_tb(DisasContext *s, int n, uint64_t dest)
>          return false;
>      }
>
> +#ifndef CONFIG_USER_ONLY
>      /* Only link tbs from inside the same guest page */
>      if ((s->tb->pc & TARGET_PAGE_MASK) != (dest & TARGET_PAGE_MASK)) {
>          return false;
>      }
> +#endif
>
>      return true;
>  }
> diff --git a/target-arm/translate.c b/target-arm/translate.c
> index 34196a821772..a43b1f61cf77 100644
> --- a/target-arm/translate.c
> +++ b/target-arm/translate.c
> @@ -4049,16 +4049,22 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn)
>      return 0;
>  }
>
> -static inline void gen_goto_tb(DisasContext *s, int n, target_ulong dest)
> +static inline bool use_goto_tb(DisasContext *s, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> +#ifndef CONFIG_USER_ONLY
> +    return (s->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||
> +           ((s->pc - 1) & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
>
> -    tb = s->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||
> -        ((s->pc - 1) & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {
> +static inline void gen_goto_tb(DisasContext *s, int n, target_ulong dest)
> +{
> +    if (use_goto_tb(s, dest)) {
>          tcg_gen_goto_tb(n);
>          gen_set_pc_im(s, dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)s->tb + n);
>      } else {
>          gen_set_pc_im(s, dest);
>          tcg_gen_exit_tb(0);
> diff --git a/target-cris/translate.c b/target-cris/translate.c
> index 9c8ff8f2308a..f28b1999a786 100644
> --- a/target-cris/translate.c
> +++ b/target-cris/translate.c
> @@ -520,16 +520,22 @@ static void t_gen_cc_jmp(TCGv pc_true, TCGv pc_false)
>      gen_set_label(l1);
>  }
>
> -static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
> +static inline bool use_goto_tb(DisasContext *dc, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = dc->tb;
> +#ifndef CONFIG_USER_ONLY
> +    return (dc->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||
> +           (dc->ppc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
>
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||
> -        (dc->ppc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {
> +static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
> +{
> +    if (use_goto_tb(dc, dest)) {
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_tl(env_pc, dest);
> -                tcg_gen_exit_tb((uintptr_t)tb + n);
> +                tcg_gen_exit_tb((uintptr_t)dc->tb + n);
>      } else {
>          tcg_gen_movi_tl(env_pc, dest);
>          tcg_gen_exit_tb(0);
> diff --git a/target-i386/translate.c b/target-i386/translate.c
> index cb725b41c37d..64d74bf24383 100644
> --- a/target-i386/translate.c
> +++ b/target-i386/translate.c
> @@ -2085,20 +2085,25 @@ static inline int insn_const_size(TCGMemOp ot)
>      }
>  }
>
> +static inline bool use_goto_tb(DisasContext *s, target_ulong pc)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    return (pc & TARGET_PAGE_MASK) == (s->tb->pc & TARGET_PAGE_MASK) ||
> +           (pc & TARGET_PAGE_MASK) == (s->pc_start & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static inline void gen_goto_tb(DisasContext *s, int tb_num, target_ulong eip)
>  {
> -    TranslationBlock *tb;
> -    target_ulong pc;
> -
> -    pc = s->cs_base + eip;
> -    tb = s->tb;
> -    /* NOTE: we handle the case where the TB spans two pages here */
> -    if ((pc & TARGET_PAGE_MASK) == (tb->pc & TARGET_PAGE_MASK) ||
> -        (pc & TARGET_PAGE_MASK) == (s->pc_start & TARGET_PAGE_MASK))  {
> +    target_ulong pc = s->cs_base + eip;
> +
> +    if (use_goto_tb(s, pc))  {
>          /* jump to same page: we can use a direct jump */
>          tcg_gen_goto_tb(tb_num);
>          gen_jmp_im(eip);
> -        tcg_gen_exit_tb((uintptr_t)tb + tb_num);
> +        tcg_gen_exit_tb((uintptr_t)s->tb + tb_num);
>      } else {
>          /* jump to another page: currently not optimized */
>          gen_jmp_im(eip);
> diff --git a/target-lm32/translate.c b/target-lm32/translate.c
> index 256a51f8498f..dd972f5b8c59 100644
> --- a/target-lm32/translate.c
> +++ b/target-lm32/translate.c
> @@ -133,16 +133,25 @@ static inline void t_gen_illegal_insn(DisasContext *dc)
>      gen_helper_ill(cpu_env);
>  }
>
> -static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
> +static inline bool use_goto_tb(DisasContext *dc, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> +    if (unlikely(dc->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (dc->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
>
> -    tb = dc->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -            likely(!dc->singlestep_enabled)) {
> +static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
> +{
> +    if (use_goto_tb(dc, dest)) {
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_tl(cpu_pc, dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)dc->tb + n);
>      } else {
>          tcg_gen_movi_tl(cpu_pc, dest);
>          if (dc->singlestep_enabled) {
> diff --git a/target-m68k/translate.c b/target-m68k/translate.c
> index e2ce6c615e07..e46356e44c78 100644
> --- a/target-m68k/translate.c
> +++ b/target-m68k/translate.c
> @@ -852,19 +852,25 @@ static inline void gen_addr_fault(DisasContext *s)
>          }                                                               \
>      } while (0)
>
> +static inline bool use_goto_tb(DisasContext *s, uint32_t dest)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    return (s->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||
> +           (s->insn_pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  /* Generate a jump to an immediate address.  */
>  static void gen_jmp_tb(DisasContext *s, int n, uint32_t dest)
>  {
> -    TranslationBlock *tb;
> -
> -    tb = s->tb;
>      if (unlikely(s->singlestep_enabled)) {
>          gen_exception(s, dest, EXCP_DEBUG);
> -    } else if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||
> -               (s->insn_pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {
> +    } else if (use_goto_tb(s, dest)) {
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_i32(QREG_PC, dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)s->tb + n);
>      } else {
>          gen_jmp_im(s, dest);
>          tcg_gen_exit_tb(0);
> diff --git a/target-microblaze/translate.c b/target-microblaze/translate.c
> index f944965a14e1..a7a8ac8f995f 100644
> --- a/target-microblaze/translate.c
> +++ b/target-microblaze/translate.c
> @@ -124,14 +124,21 @@ static inline void t_gen_raise_exception(DisasContext *dc, uint32_t index)
>      dc->is_jmp = DISAS_UPDATE;
>  }
>
> +static inline bool use_goto_tb(DisasContext *dc, target_ulong dest)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    return (dc->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = dc->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {
> +    if (use_goto_tb(dc, dest)) {
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_tl(cpu_SR[SR_PC], dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)dc->tb + n);
>      } else {
>          tcg_gen_movi_tl(cpu_SR[SR_PC], dest);
>          tcg_gen_exit_tb(0);
> diff --git a/target-mips/translate.c b/target-mips/translate.c
> index a3a05ec66dd2..ddfb9244d7e3 100644
> --- a/target-mips/translate.c
> +++ b/target-mips/translate.c
> @@ -4191,15 +4191,25 @@ static void gen_trap (DisasContext *ctx, uint32_t opc,
>      tcg_temp_free(t1);
>  }
>
> +static inline bool use_goto_tb(DisasContext *ctx, target_ulong dest)
> +{
> +    if (unlikely(ctx->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (ctx->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static inline void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = ctx->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -        likely(!ctx->singlestep_enabled)) {
> +    if (use_goto_tb(ctx, dest)) {
>          tcg_gen_goto_tb(n);
>          gen_save_pc(dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)ctx->tb + n);
>      } else {
>          gen_save_pc(dest);
>          if (ctx->singlestep_enabled) {
> diff --git a/target-moxie/translate.c b/target-moxie/translate.c
> index a437e2ab6026..58200c25d3f4 100644
> --- a/target-moxie/translate.c
> +++ b/target-moxie/translate.c
> @@ -121,17 +121,26 @@ void moxie_translate_init(void)
>      done_init = 1;
>  }
>
> +static inline bool use_goto_tb(DisasContext *ctx, target_ulong dest)
> +{
> +    if (unlikely(ctx->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (ctx->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static inline void gen_goto_tb(CPUMoxieState *env, DisasContext *ctx,
>                                 int n, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = ctx->tb;
> -
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -        !ctx->singlestep_enabled) {
> +    if (use_goto_tb(ctx, dest)) {
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_i32(cpu_pc, dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)ctx->tb + n);
>      } else {
>          tcg_gen_movi_i32(cpu_pc, dest);
>          if (ctx->singlestep_enabled) {
> diff --git a/target-openrisc/translate.c b/target-openrisc/translate.c
> index 5d0ab442a872..d4f1f260e425 100644
> --- a/target-openrisc/translate.c
> +++ b/target-openrisc/translate.c
> @@ -190,15 +190,25 @@ static void check_ov64s(DisasContext *dc)
>  }
>  #endif*/
>
> +static inline bool use_goto_tb(DisasContext *dc, target_ulong dest)
> +{
> +    if (unlikely(dc->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (dc->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = dc->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -                                       likely(!dc->singlestep_enabled)) {
> +    if (use_goto_tb(dc, dest)) {
>          tcg_gen_movi_tl(cpu_pc, dest);
>          tcg_gen_goto_tb(n);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)dc->tb + n);
>      } else {
>          tcg_gen_movi_tl(cpu_pc, dest);
>          if (dc->singlestep_enabled) {
> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
> index b3860ecdea9c..d485d7c7cb18 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -3822,19 +3822,29 @@ static inline void gen_update_cfar(DisasContext *ctx, target_ulong nip)
>  #endif
>  }
>
> +static inline bool use_goto_tb(DisasContext *ctx, target_ulong dest)
> +{
> +    if (unlikely(ctx->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (ctx->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  /***                                Branch                                 ***/
>  static inline void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = ctx->tb;
>      if (NARROW_MODE(ctx)) {
>          dest = (uint32_t) dest;
>      }
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -        likely(!ctx->singlestep_enabled)) {
> +    if (use_goto_tb(ctx, dest)) {
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_tl(cpu_nip, dest & ~3);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)ctx->tb + n);
>      } else {
>          tcg_gen_movi_tl(cpu_nip, dest & ~3);
>          if (unlikely(ctx->singlestep_enabled)) {
> diff --git a/target-s390x/translate.c b/target-s390x/translate.c
> index c5179fe05d7e..e99eb5cb0169 100644
> --- a/target-s390x/translate.c
> +++ b/target-s390x/translate.c
> @@ -608,12 +608,17 @@ static void gen_op_calc_cc(DisasContext *s)
>
>  static int use_goto_tb(DisasContext *s, uint64_t dest)
>  {
> -    /* NOTE: we handle the case where the TB spans two pages here */
> -    return (((dest & TARGET_PAGE_MASK) == (s->tb->pc & TARGET_PAGE_MASK)
> -             || (dest & TARGET_PAGE_MASK) == (s->pc & TARGET_PAGE_MASK))
> -            && !s->singlestep_enabled
> -            && !(s->tb->cflags & CF_LAST_IO)
> -            && !(s->tb->flags & FLAG_MASK_PER));
> +    if (unlikely(s->singlestep_enabled) ||
> +        (s->tb->cflags & CF_LAST_IO) ||
> +        (s->tb->flags & FLAG_MASK_PER)) {
> +        return false;
> +    }
> +#ifndef CONFIG_USER_ONLY
> +    return (dest & TARGET_PAGE_MASK) == (s->tb->pc & TARGET_PAGE_MASK) ||
> +           (dest & TARGET_PAGE_MASK) == (s->pc & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
>  }
>
>  static void account_noninline_branch(DisasContext *s, int cc_op)
> diff --git a/target-sh4/translate.c b/target-sh4/translate.c
> index 7c189680a7a4..53f782c05467 100644
> --- a/target-sh4/translate.c
> +++ b/target-sh4/translate.c
> @@ -205,17 +205,26 @@ static void gen_write_sr(TCGv src)
>      tcg_gen_andi_i32(cpu_sr_t, cpu_sr_t, 1);
>  }
>
> -static void gen_goto_tb(DisasContext * ctx, int n, target_ulong dest)
> +static inline bool use_goto_tb(DisasContext *ctx, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = ctx->tb;
> +    if (unlikely(ctx->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (ctx->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
>
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -	!ctx->singlestep_enabled) {
> +static void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
> +{
> +    if (use_goto_tb(ctx, dest)) {
>  	/* Use a direct jump if in same page and singlestep not enabled */
>          tcg_gen_goto_tb(n);
>          tcg_gen_movi_i32(cpu_pc, dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)ctx->tb + n);
>      } else {
>          tcg_gen_movi_i32(cpu_pc, dest);
>          if (ctx->singlestep_enabled)
> diff --git a/target-sparc/translate.c b/target-sparc/translate.c
> index 7998ff57bf09..d154e3f7b633 100644
> --- a/target-sparc/translate.c
> +++ b/target-sparc/translate.c
> @@ -303,20 +303,30 @@ static inline TCGv gen_dest_gpr(DisasContext *dc, int reg)
>      }
>  }
>
> +static inline bool use_goto_tb(DisasContext *s, target_ulong pc,
> +                               target_ulong npc)
> +{
> +    if (unlikely(s->singlestep)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (pc & TARGET_PAGE_MASK) == (s->tb->pc & TARGET_PAGE_MASK) &&
> +           (npc & TARGET_PAGE_MASK) == (s->tb->pc & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static inline void gen_goto_tb(DisasContext *s, int tb_num,
>                                 target_ulong pc, target_ulong npc)
>  {
> -    TranslationBlock *tb;
> -
> -    tb = s->tb;
> -    if ((pc & TARGET_PAGE_MASK) == (tb->pc & TARGET_PAGE_MASK) &&
> -        (npc & TARGET_PAGE_MASK) == (tb->pc & TARGET_PAGE_MASK) &&
> -        !s->singlestep)  {
> +    if (use_goto_tb(s, pc, npc))  {
>          /* jump to same page: we can use a direct jump */
>          tcg_gen_goto_tb(tb_num);
>          tcg_gen_movi_tl(cpu_pc, pc);
>          tcg_gen_movi_tl(cpu_npc, npc);
> -        tcg_gen_exit_tb((uintptr_t)tb + tb_num);
> +        tcg_gen_exit_tb((uintptr_t)s->tb + tb_num);
>      } else {
>          /* jump to another page: currently not optimized */
>          tcg_gen_movi_tl(cpu_pc, pc);
> diff --git a/target-tricore/translate.c b/target-tricore/translate.c
> index 912bf226bedc..0237e7bea835 100644
> --- a/target-tricore/translate.c
> +++ b/target-tricore/translate.c
> @@ -3236,15 +3236,25 @@ static inline void gen_save_pc(target_ulong pc)
>      tcg_gen_movi_tl(cpu_PC, pc);
>  }
>
> +static inline bool use_goto_tb(DisasContext *ctx, target_ulong dest)
> +{
> +    if (unlikely(ctx->singlestep_enabled)) {
> +        return false;
> +    }
> +
> +#ifndef CONFIG_USER_ONLY
> +    return (ctx->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
> +
>  static inline void gen_goto_tb(DisasContext *ctx, int n, target_ulong dest)
>  {
> -    TranslationBlock *tb;
> -    tb = ctx->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) &&
> -        likely(!ctx->singlestep_enabled)) {
> +    if (use_goto_tb(ctx, dest)) {
>          tcg_gen_goto_tb(n);
>          gen_save_pc(dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)ctx->tb + n);
>      } else {
>          gen_save_pc(dest);
>          if (ctx->singlestep_enabled) {
> diff --git a/target-unicore32/translate.c b/target-unicore32/translate.c
> index 39af3af05f15..307f7b205924 100644
> --- a/target-unicore32/translate.c
> +++ b/target-unicore32/translate.c
> @@ -1089,15 +1089,21 @@ static void disas_ucf64_insn(CPUUniCore32State *env, DisasContext *s, uint32_t i
>      }
>  }
>
> -static inline void gen_goto_tb(DisasContext *s, int n, uint32_t dest)
> +static inline bool use_goto_tb(DisasContext *s, uint32_t dest)
>  {
> -    TranslationBlock *tb;
> +#ifndef CONFIG_USER_ONLY
> +    return (s->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +#else
> +    return true;
> +#endif
> +}
>
> -    tb = s->tb;
> -    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {
> +static inline void gen_goto_tb(DisasContext *s, int n, uint32_t dest)
> +{
> +    if (use_goto_tb(s, dest)) {
>          tcg_gen_goto_tb(n);
>          gen_set_pc_im(dest);
> -        tcg_gen_exit_tb((uintptr_t)tb + n);
> +        tcg_gen_exit_tb((uintptr_t)s->tb + n);
>      } else {
>          gen_set_pc_im(dest);
>          tcg_gen_exit_tb(0);
> diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
> index 989448846902..9eac56e2a5bc 100644
> --- a/target-xtensa/translate.c
> +++ b/target-xtensa/translate.c
> @@ -418,9 +418,11 @@ static void gen_jump(DisasContext *dc, TCGv dest)
>  static void gen_jumpi(DisasContext *dc, uint32_t dest, int slot)
>  {
>      TCGv_i32 tmp = tcg_const_i32(dest);
> +#ifndef CONFIG_USER_ONLY
>      if (((dc->tb->pc ^ dest) & TARGET_PAGE_MASK) != 0) {
>          slot = -1;
>      }
> +#endif
>      gen_jump_slot(dc, tmp, slot);
>      tcg_temp_free(tmp);
>  }
> @@ -446,9 +448,11 @@ static void gen_callw(DisasContext *dc, int callinc, TCGv_i32 dest)
>  static void gen_callwi(DisasContext *dc, int callinc, uint32_t dest, int slot)
>  {
>      TCGv_i32 tmp = tcg_const_i32(dest);
> +#ifndef CONFIG_USER_ONLY
>      if (((dc->tb->pc ^ dest) & TARGET_PAGE_MASK) != 0) {
>          slot = -1;
>      }
> +#endif
>      gen_callw_slot(dc, callinc, tmp, slot);
>      tcg_temp_free(tmp);
>  }
> diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
> index ace39619ef89..f217e8074715 100644
> --- a/tcg/tcg-op.h
> +++ b/tcg/tcg-op.h
> @@ -759,9 +759,12 @@ static inline void tcg_gen_exit_tb(uintptr_t val)
>   *
>   * See tcg/README for more info about this TCG operation.
>   *
> - * NOTE: Direct jumps with goto_tb are only safe within the pages this TB
> - * resides in because we don't take care of direct jumps when address mapping
> - * changes, e.g. in tlb_flush().
> + * NOTE: In softmmu emulation, direct jumps with goto_tb are only safe within
> + * the pages this TB resides in because we don't take care of direct jumps when
> + * address mapping changes, e.g. in tlb_flush(). In user mode, there's only a
> + * static address translation, so the destination address is always valid, TBs
> + * are always invalidated properly, and direct jumps are reset when mapping
> + * changes.
>   */
>  void tcg_gen_goto_tb(unsigned idx);


--
Alex Bennée

  reply	other threads:[~2016-04-21 14:42 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-20 21:15 [Qemu-devel] [PATCH v4 00/10] tcg: Direct block chaining clean-up Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 01/10] tcg: Clean up direct block chaining data fields Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 02/10] tcg: Use uintptr_t type for jmp_list_{next|first} fields of TB Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 03/10] tcg: Rearrange tb_link_page() to avoid forward declaration Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 04/10] tcg: Init TB's direct jumps before making it visible Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 05/10] tcg: Clarify thread safety check in tb_add_jump() Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 06/10] tcg: Rename tb_jmp_remove() to tb_remove_from_jmp_list() Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 07/10] tcg: Extract removing of jumps to TB from tb_phys_invalidate() Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 08/10] tcg: Clean up tb_jmp_unlink() Sergey Fedorov
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 09/10] tcg: Clean up direct block chaining safety checks Sergey Fedorov
2016-04-21 13:18   ` Alex Bennée
2016-04-21 15:08     ` Sergey Fedorov
2016-04-21 15:45       ` Alex Bennée
2016-04-20 21:15 ` [Qemu-devel] [PATCH v4 10/10] tcg: Allow goto_tb to any target PC in user mode Sergey Fedorov
2016-04-21 14:42   ` Alex Bennée [this message]
2016-04-28 18:03   ` Richard Henderson
2016-04-28 11:16 ` [Qemu-devel] [PATCH v4 00/10] tcg: Direct block chaining clean-up Alex Bennée
2016-04-28 11:33   ` Sergey Fedorov
2016-04-28 16:34     ` Richard Henderson

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