vhost: Fix mmap size calculation

I had a bug where a requested size of 1G was resulting in
an aligned size of '1G + 2M', resulting in an OOM error.

Previous code was adding one huge page size
when memory is already aligned.

Change-Id: Idd3aa0e9b893fb3efccba6ae1c7161e26d3f9456
Signed-off-by: Pierre Pfister <ppfister@cisco.com>

diff --git a/src/vnet/devices/virtio/vhost-user.c b/src/vnet/devices/virtio/vhost-user.c
index bcfef9f..3ac7697 100644 (file)
--- a/src/vnet/devices/virtio/vhost-user.c
+++ b/src/vnet/devices/virtio/vhost-user.c
@@ -303,7 +303,7 @@ unmap_all_mem_regions (vhost_user_intf_t * vui)
 
          ssize_t map_sz = (vui->regions[i].memory_size +
                            vui->regions[i].mmap_offset +
-                           page_sz) & ~(page_sz - 1);
+                           page_sz - 1) & ~(page_sz - 1);
 
          r =
            munmap (vui->region_mmap_addr[i] - vui->regions[i].mmap_offset,
@@ -917,7 +917,7 @@ vhost_user_socket_read (unix_file_t * uf)
          /* align size to 2M page */
          ssize_t map_sz = (vui->regions[i].memory_size +
                            vui->regions[i].mmap_offset +
-                           page_sz) & ~(page_sz - 1);
+                           page_sz - 1) & ~(page_sz - 1);
 
          vui->region_mmap_addr[i] = mmap (0, map_sz, PROT_READ | PROT_WRITE,
                                           MAP_SHARED, fds[i], 0);
@@ -1168,7 +1168,7 @@ vhost_user_socket_read (unix_file_t * uf)
        /* align size to 2M page */
        long page_sz = get_huge_page_size (fd);
        ssize_t map_sz =
-         (msg.log.size + msg.log.offset + page_sz) & ~(page_sz - 1);
+         (msg.log.size + msg.log.offset + page_sz - 1) & ~(page_sz - 1);
 
        vui->log_base_addr = mmap (0, map_sz, PROT_READ | PROT_WRITE,
                                   MAP_SHARED, fd, 0);