tcg: Note requirement on atomic direct jump patching

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1461341333-19646-12-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 30cdd699f400c349fed447bffff6e787c8a27b4d..6c113a3d20107ad4a48073805a7ad58dd7879ccf 100644 (file)
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -230,6 +230,7 @@ static inline void tlb_flush_by_mmuidx(CPUState *cpu, ...)
     || defined(__sparc__) || defined(__aarch64__) \
     || defined(__s390x__) || defined(__mips__) \
     || defined(CONFIG_TCG_INTERPRETER)
+/* NOTE: Direct jump patching must be atomic to be thread-safe. */
 #define USE_DIRECT_JUMP
 #endif