From d3a2a1d80331b437bcfa0dc43f2c447d3104898e Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 20 Jun 2021 15:28:18 -0700 Subject: [PATCH] accel/tcg: Introduce translator_use_goto_tb MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a generic version of the common use_goto_tb test. Various targets avoid the page crossing test for CONFIG_USER_ONLY, but that is wrong: mmap and mprotect can change page permissions. Reviewed-by: Max Filippov Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- accel/tcg/translator.c | 11 +++++++++++ include/exec/translator.h | 10 ++++++++++ 2 files changed, 21 insertions(+) diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c index 1d32732198..59804af37b 100644 --- a/accel/tcg/translator.c +++ b/accel/tcg/translator.c @@ -31,6 +31,17 @@ void translator_loop_temp_check(DisasContextBase *db) } } +bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest) +{ + /* Suppress goto_tb in the case of single-steping. */ + if (db->singlestep_enabled || singlestep) { + return false; + } + + /* Check for the dest on the same page as the start of the TB. */ + return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0; +} + void translator_loop(const TranslatorOps *ops, DisasContextBase *db, CPUState *cpu, TranslationBlock *tb, int max_insns) { diff --git a/include/exec/translator.h b/include/exec/translator.h index 24232ead41..dd9c06d40d 100644 --- a/include/exec/translator.h +++ b/include/exec/translator.h @@ -145,6 +145,16 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db, void translator_loop_temp_check(DisasContextBase *db); +/** + * translator_use_goto_tb + * @db: Disassembly context + * @dest: target pc of the goto + * + * Return true if goto_tb is allowed between the current TB + * and the destination PC. + */ +bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest); + /* * Translator Load Functions *