3 files changed, 24 insertions, 0 deletions
diff --git a/exec.c b/exec.c
index 37468399fc..61a55325ef 100644
--- a/exec.c
+++ b/exec.c
@@ -2386,6 +2386,10 @@ ram_addr_t qemu_ram_alloc(ram_addr_t size)
     }
     addr = phys_ram_alloc_offset;
     phys_ram_alloc_offset = TARGET_PAGE_ALIGN(phys_ram_alloc_offset + size);
+
+    if (kvm_enabled())
+        kvm_setup_guest_memory(phys_ram_base + addr, size);
+
     return addr;
 }
 
diff --git a/kvm-all.c b/kvm-all.c
index 28c9c07ccb..2b7d535030 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -656,3 +656,21 @@ int kvm_has_sync_mmu(void)
 
     return 0;
 }
+
+void kvm_setup_guest_memory(void *start, size_t size)
+{
+    if (!kvm_has_sync_mmu()) {
+#ifdef MADV_DONTFORK
+        int ret = madvise(start, size, MADV_DONTFORK);
+
+        if (ret) {
+            perror("madvice");
+            exit(1);
+        }
+#else
+        fprintf(stderr,
+                "Need MADV_DONTFORK in absence of synchronous KVM MMU\n");
+        exit(1);
+#endif
+    }
+}
diff --git a/kvm.h b/kvm.h
index efce1450d5..5a52f51cb9 100644
--- a/kvm.h
+++ b/kvm.h
@@ -46,6 +46,8 @@ int kvm_log_stop(target_phys_addr_t phys_addr, target_phys_addr_t len);
 
 int kvm_has_sync_mmu(void);
 
+void kvm_setup_guest_memory(void *start, size_t size);
+
 int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
 int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);