1 files changed, 3 insertions, 15 deletions
diff --git a/exec.c b/exec.c
index dd4833d316..c9fa17de6f 100644
--- a/exec.c
+++ b/exec.c
@@ -2536,26 +2536,14 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
             exit(1);
 #endif
         } else {
-#if defined(TARGET_S390X) && defined(CONFIG_KVM)
-            /* 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 | MAP_FIXED, -1, 0);
-            if (new_block->host == MAP_FAILED) {
-                fprintf(stderr, "Allocating RAM failed\n");
-                abort();
-            }
-#else
             if (xen_enabled()) {
                 xen_ram_alloc(new_block->offset, size, mr);
+            } else if (kvm_enabled()) {
+                /* some s390/kvm configurations have special constraints */
+                new_block->host = kvm_vmalloc(size);
             } else {
                 new_block->host = qemu_vmalloc(size);
             }
-#endif
             qemu_madvise(new_block->host, size, QEMU_MADV_MERGEABLE);
         }
     }