1 files changed, 12 insertions, 3 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 464621d18eb2..5016f19e1661 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -725,9 +725,10 @@ static void free_unmap_vmap_area_addr(unsigned long addr)
 #define VMAP_BBMAP_BITS_MIN     (VMAP_MAX_ALLOC*2)
 #define VMAP_MIN(x, y)          ((x) < (y) ? (x) : (y)) /* can't use min() */
 #define VMAP_MAX(x, y)          ((x) > (y) ? (x) : (y)) /* can't use max() */
-#define VMAP_BBMAP_BITS         VMAP_MIN(VMAP_BBMAP_BITS_MAX,           \
-                                        VMAP_MAX(VMAP_BBMAP_BITS_MIN,   \
-                                                VMALLOC_PAGES / NR_CPUS / 16))
+#define VMAP_BBMAP_BITS         \
+                VMAP_MIN(VMAP_BBMAP_BITS_MAX,   \
+                VMAP_MAX(VMAP_BBMAP_BITS_MIN,   \
+                        VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
 
 #define VMAP_BLOCK_SIZE         (VMAP_BBMAP_BITS * PAGE_SIZE)
 
@@ -2139,6 +2140,14 @@ struct vm_struct *alloc_vm_area(size_t size)
                 return NULL;
         }
 
+        /*
+         * If the allocated address space is passed to a hypercall
+         * before being used then we cannot rely on a page fault to
+         * trigger an update of the page tables.  So sync all the page
+         * tables here.
+         */
+        vmalloc_sync_all();
+
         return area;
 }
 EXPORT_SYMBOL_GPL(alloc_vm_area);