Userspace guest address offsetting

Re-implement GUEST_BASE support.
Offset guest ddress space by default if the guest binary contains
regions below the host mmap_min_addr.
Implement support for i386, x86-64 and arm hosts.

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Paul Brook <paul@codesourcery.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/cpu-all.h b/cpu-all.h
index 116678677f..96b25fca80 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -624,8 +624,13 @@ static inline void stfq_be_p(void *ptr, float64 v)
 /* On some host systems the guest address space is reserved on the host.
  * This allows the guest address space to be offset to a convenient location.
  */
-//#define GUEST_BASE 0x20000000
-#define GUEST_BASE 0
+#if defined(CONFIG_USE_GUEST_BASE)
+extern unsigned long guest_base;
+extern int have_guest_base;
+#define GUEST_BASE guest_base
+#else
+#define GUEST_BASE 0ul
+#endif
 
 /* All direct uses of g2h and h2g need to go away for usermode softmmu.  */
 #define g2h(x) ((void *)((unsigned long)(x) + GUEST_BASE))