======
Subject: avoid allocation failures during fork/exec for migrate/hotplug

From: Andrea Arcangeli <aarcange@redhat.com>

Mark all guest physical memory as MADV_DONTFORK to avoid false positive
allocation failures during fork in migrate/netdev hotplug.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---

diff --git a/exec.c b/exec.c
index db9ff55..9e2aa12 100644
--- a/exec.c
+++ b/exec.c
@@ -2851,6 +2851,9 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name,
             new_block->host = qemu_vmalloc(size);
 #endif
             qemu_madvise(new_block->host, size, QEMU_MADV_MERGEABLE);
+
+            /* no allocation failures during fork/exec for migrate/hotplug */
+            qemu_madvise(new_block->host, size, QEMU_MADV_DONTFORK);
         }
     }