Merge branch 's390-next' of git://repo.or.cz/qemu/agraf

* 's390-next' of git://repo.or.cz/qemu/agraf:
  s390x: complain when allocating ram fails
  s390x: fix memory detection for guests > 64GB
  s390x: change mapping base to allow guests > 2GB
  s390x: Fix debugging for unknown sigp order codes
  s390x: build s390x by default
  s390x: remove compatibility cc field
  s390x: Adjust GDB stub
  s390x: translate engine for s390x CPU
  s390x: Adjust internal kvm code
  s390x: Implement opcode helpers
  s390x: helper functions for system emulation
  s390x: Shift variables in CPUState for memset(0)
  s390x: keep hint on virtio managing size
  s390x: make kvm exported functions conditional on kvm
  s390x: s390x-linux-user support
  tcg: extend max tcg opcodes when using 64-on-32bit
  s390x: fix smp support for kvm

1 files changed, 11 insertions, 3 deletions

diff --git a/exec.c b/exec.c
index a6df2d6139..a4785b25f8 100644
--- a/exec.c
+++ b/exec.c
@@ -2910,10 +2910,18 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name,
 #endif
         } else {
 #if defined(TARGET_S390X) && defined(CONFIG_KVM)
-            /* XXX S390 KVM requires the topmost vma of the RAM to be < 256GB */
-            new_block->host = mmap((void*)0x1000000, size,
+            /* S390 KVM requires the topmost vma of the RAM to be smaller than
+               an system defined value, which is at least 256GB. Larger systems
+               have larger values. We put the guest between the end of data
+               segment (system break) and this value. We use 32GB as a base to
+               have enough room for the system break to grow. */
+            new_block->host = mmap((void*)0x800000000, size,
                                    PROT_EXEC|PROT_READ|PROT_WRITE,
-                                   MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+                                   MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+            if (new_block->host == MAP_FAILED) {
+                fprintf(stderr, "Allocating RAM failed\n");
+                abort();
+            }
 #else
             if (xen_mapcache_enabled()) {
                 xen_ram_alloc(new_block->offset, size);