From ce9a92411db074b081cced02f164735bcd6bbb41 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Tue, 13 Jan 2009 18:36:17 -0200
Subject: [PATCH] Make --mem-path memory allocation depend on mmu notifiers

Without mmu notifiers usage of hugepages to back guest memory can cause
memory corruption.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
 vl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/vl.c b/vl.c
index dd26f079a0..9557a06485 100644
--- a/vl.c
+++ b/vl.c
@@ -4708,6 +4708,11 @@ static void *alloc_mem_area(size_t memory, unsigned long *len, const char *path)
     void *area;
     int fd;
 
+    if (!kvm_has_sync_mmu()) {
+        fprintf(stderr, "host lacks mmu notifiers, disabling --mem-path\n");
+        return NULL;
+    }
+
     if (asprintf(&filename, "%s/kvm.XXXXXX", path) == -1)
 	return NULL;
 
-- 
2.11.4.GIT