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authorRoman Bolshakov <r.bolshakov@yadro.com>2021-01-13 06:28:07 +0300
committerRichard Henderson <richard.henderson@linaro.org>2021-01-23 12:13:00 -1000
commit653b87eb36045b506b79f0bb433016ef1c54bc9a (patch)
tree9072762b0292a3b668f5e55f94da53e1edb9c5a2 /include/qemu/osdep.h
parent65269192241104342e3b1ba2b7b0f50e5042052e (diff)
downloadfocaccia-qemu-653b87eb36045b506b79f0bb433016ef1c54bc9a.tar.gz
focaccia-qemu-653b87eb36045b506b79f0bb433016ef1c54bc9a.zip
tcg: Toggle page execution for Apple Silicon
Pages can't be both write and executable at the same time on Apple
Silicon. macOS provides public API to switch write protection [1] for
JIT applications, like TCG.

1. https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon

Tested-by: Alexander Graf <agraf@csgraf.de>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20210113032806.18220-1-r.bolshakov@yadro.com>
[rth: Inline the qemu_thread_jit_* functions;
 drop the MAP_JIT change for a follow-on patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'include/qemu/osdep.h')
-rw-r--r--include/qemu/osdep.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index a434382c58..b6ffdc15bf 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -119,6 +119,10 @@ extern int daemon(int, int);
 #include "sysemu/os-posix.h"
 #endif
 
+#ifdef __APPLE__
+#include <AvailabilityMacros.h>
+#endif
+
 #include "glib-compat.h"
 #include "qemu/typedefs.h"
 
@@ -682,4 +686,28 @@ char *qemu_get_host_name(Error **errp);
  */
 size_t qemu_get_host_physmem(void);
 
+/*
+ * Toggle write/execute on the pages marked MAP_JIT
+ * for the current thread.
+ */
+#if defined(MAC_OS_VERSION_11_0) && \
+    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
+static inline void qemu_thread_jit_execute(void)
+{
+    if (__builtin_available(macOS 11.0, *)) {
+        pthread_jit_write_protect_np(true);
+    }
+}
+
+static inline void qemu_thread_jit_write(void)
+{
+    if (__builtin_available(macOS 11.0, *)) {
+        pthread_jit_write_protect_np(false);
+    }
+}
+#else
+static inline void qemu_thread_jit_write(void) {}
+static inline void qemu_thread_jit_execute(void) {}
+#endif
+
 #endif