kvmvapic: Disable if there is insufficient memory

[qemu.git] / qemu-barrier.h

diff --git a/qemu-barrier.h b/qemu-barrier.h
index f0b842e5b250fedf00849482659f449649b5c5d0..7e11197814e1e2de566f837d8c9cda409fd9f382 100644 (file)
--- a/qemu-barrier.h
+++ b/qemu-barrier.h
@@ -7,12 +7,13 @@
 #if defined(__i386__)
 
 /*
- * Because of the strongly ordered x86 storage model, wmb() is a nop
+ * Because of the strongly ordered x86 storage model, wmb() and rmb() are nops
  * on x86(well, a compiler barrier only).  Well, at least as long as
  * qemu doesn't do accesses to write-combining memory or non-temporal
  * load/stores from C code.
  */
 #define smp_wmb()   barrier()
+#define smp_rmb()   barrier()
 /*
  * We use GCC builtin if it's available, as that can use
  * mfence on 32 bit as well, e.g. if built with -march=pentium-m.
@@ -27,6 +28,7 @@
 #elif defined(__x86_64__)
 
 #define smp_wmb()   barrier()
+#define smp_rmb()   barrier()
 #define smp_mb() asm volatile("mfence" ::: "memory")
 
 #elif defined(_ARCH_PPC)
@@ -37,6 +39,13 @@
  * each other
  */
 #define smp_wmb()   asm volatile("eieio" ::: "memory")
+
+#if defined(__powerpc64__)
+#define smp_rmb()   asm volatile("lwsync" ::: "memory")
+#else
+#define smp_rmb()   asm volatile("sync" ::: "memory")
+#endif
+
 #define smp_mb()   asm volatile("sync" ::: "memory")
 
 #else
@@ -45,10 +54,11 @@
  * For (host) platforms we don't have explicit barrier definitions
  * for, we use the gcc __sync_synchronize() primitive to generate a
  * full barrier.  This should be safe on all platforms, though it may
- * be overkill for wmb().
+ * be overkill for wmb() and rmb().
  */
 #define smp_wmb()   __sync_synchronize()
 #define smp_mb()   __sync_synchronize()
+#define smp_rmb()   __sync_synchronize()
 
 #endif