From cfd405eae6ad7a0e20b006e3295c5e8edab3ce3f Mon Sep 17 00:00:00 2001 From: Alex Bennée Date: Sat, 13 Feb 2021 13:03:22 +0000 Subject: accel/tcg: allow plugin instrumentation to be disable via cflags MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When icount is enabled and we recompile an MMIO access we end up double counting the instruction execution. To avoid this we introduce the CF_MEMI cflag which only allows memory instrumentation for the next TB (which won't yet have been counted). As this is part of the hashed compile flags we will only execute the generated TB while coming out of a cpu_io_recompile. While we are at it delete the old TODO. We might as well keep the translation handy as it's likely you will repeatedly hit it on each MMIO access. Reported-by: Aaron Lindsay Signed-off-by: Alex Bennée Tested-by: Aaron Lindsay Reviewed-by: Richard Henderson Message-Id: <20210213130325.14781-21-alex.bennee@linaro.org> --- accel/tcg/translator.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'accel/tcg/translator.c') diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c index a49a794065..2dfc27102f 100644 --- a/accel/tcg/translator.c +++ b/accel/tcg/translator.c @@ -58,7 +58,8 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db, ops->tb_start(db, cpu); tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ - plugin_enabled = plugin_gen_tb_start(cpu, tb); + plugin_enabled = plugin_gen_tb_start(cpu, tb, + tb_cflags(db->tb) & CF_MEMI_ONLY); while (true) { db->num_insns++; @@ -100,6 +101,8 @@ void translator_loop(const TranslatorOps *ops, DisasContextBase *db, gen_io_start(); ops->translate_insn(db, cpu); } else { + /* we should only see CF_MEMI_ONLY for io_recompile */ + tcg_debug_assert(!(tb_cflags(db->tb) & CF_MEMI_ONLY)); ops->translate_insn(db, cpu); } -- cgit 1.4.1