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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2010-06-25 16:56:49 +0200 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2010-07-22 05:52:08 +0200 |
| commit | 1d93f0f03d4d911fdf1dc4ef529d8b2a0c0765f2 (patch) | |
| tree | 843739dbf41d3162ea8c25d8603d6797c0a7ac9c | |
| parent | 1e29a009e35f2184236d09f45e58bc6a954074c6 (diff) | |
| download | qemu-1d93f0f03d4d911fdf1dc4ef529d8b2a0c0765f2.zip qemu-1d93f0f03d4d911fdf1dc4ef529d8b2a0c0765f2.tar.gz qemu-1d93f0f03d4d911fdf1dc4ef529d8b2a0c0765f2.tar.bz2 | |
Introduce proper compiler barrier
Define barrier() as optimization barrier and replace (potentially
unreliable) asm("") fences.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
| -rw-r--r-- | cpu-exec.c | 5 | ||||
| -rw-r--r-- | qemu-barrier.h | 3 |
2 files changed, 6 insertions, 2 deletions
@@ -21,6 +21,7 @@ #include "disas.h" #include "tcg.h" #include "kvm.h" +#include "qemu-barrier.h" #if !defined(CONFIG_SOFTMMU) #undef EAX @@ -233,7 +234,7 @@ int cpu_exec(CPUState *env1) use it. */ QEMU_BUILD_BUG_ON (sizeof (saved_env_reg) != sizeof (env)); saved_env_reg = (host_reg_t) env; - asm(""); + barrier(); env = env1; if (exit_request) { @@ -669,7 +670,7 @@ int cpu_exec(CPUState *env1) #endif /* restore global registers */ - asm(""); + barrier(); env = (void *) saved_env_reg; /* fail safe : never use cpu_single_env outside cpu_exec() */ diff --git a/qemu-barrier.h b/qemu-barrier.h index 3bd1075..b77fce2 100644 --- a/qemu-barrier.h +++ b/qemu-barrier.h @@ -4,4 +4,7 @@ /* FIXME: arch dependant, x86 version */ #define smp_wmb() asm volatile("" ::: "memory") +/* Compiler barrier */ +#define barrier() asm volatile("" ::: "memory") + #endif |