xen/xenpaging.pagefile.patch

Subject: xenpaging: Open paging file only if xenpaging_init() succeeds

Open paging file only if xenpaging_init() succeeds. It can fail if the host
does not support the required virtualization features such as EPT or if
xenpaging was already started for this domain_id.

(xen-unstable changeset:   22435:7818ea9045fd)

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Already-Acked-by: Patrick Colp <pjcolp@cs.ubc.ca>
Already-Acked-by: Keir Fraser <keir.fraser@citrix.com>

---
 tools/xenpaging/xenpaging.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

--- xen-4.0.1-testing.orig/tools/xenpaging/xenpaging.c
+++ xen-4.0.1-testing/tools/xenpaging/xenpaging.c
@@ -495,15 +495,6 @@ int main(int argc, char *argv[])
 
     victims = calloc(num_pages, sizeof(xenpaging_victim_t));
 
-    /* Open file */
-    sprintf(filename, "page_cache_%d", domain_id);
-    fd = open(filename, open_flags, open_mode);
-    if ( fd < 0 )
-    {
-        perror("failed to open file");
-        return -1;
-    }
-
     /* Seed random-number generator */
     srand(time(NULL));
 
@@ -515,6 +506,15 @@ int main(int argc, char *argv[])
         goto out;
     }
 
+    /* Open file */
+    sprintf(filename, "page_cache_%d", domain_id);
+    fd = open(filename, open_flags, open_mode);
+    if ( fd < 0 )
+    {
+        perror("failed to open file");
+        return -1;
+    }
+
     /* Evict pages */
     memset(victims, 0, sizeof(xenpaging_victim_t) * num_pages);
     for ( i = 0; i < num_pages; i++ )