virtio: pass argument by value for virtqueue_map_iovec()

Pass num_sg by value instead of by pointer, as num_sg is never modified in
virtqueue_map_iovec().

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1541139396-4727-1-git-send-email-dongli.zhang@oracle.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 5828ed14dfcab07cd096a858b28ebb4ef7a60d4f..22bd1ac34efb2425e266619067eb7c69f62268aa 100644 (file)
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -796,13 +796,13 @@ static void virtqueue_undo_map_desc(unsigned int out_num, unsigned int in_num,
 }
 
 static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg,
-                                hwaddr *addr, unsigned int *num_sg,
+                                hwaddr *addr, unsigned int num_sg,
                                 int is_write)
 {
     unsigned int i;
     hwaddr len;
 
-    for (i = 0; i < *num_sg; i++) {
+    for (i = 0; i < num_sg; i++) {
         len = sg[i].iov_len;
         sg[i].iov_base = dma_memory_map(vdev->dma_as,
                                         addr[i], &len, is_write ?
@@ -821,8 +821,8 @@ static void virtqueue_map_iovec(VirtIODevice *vdev, struct iovec *sg,
 
 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem)
 {
-    virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, &elem->in_num, 1);
-    virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, &elem->out_num, 0);
+    virtqueue_map_iovec(vdev, elem->in_sg, elem->in_addr, elem->in_num, 1);
+    virtqueue_map_iovec(vdev, elem->out_sg, elem->out_addr, elem->out_num, 0);
 }
 
 static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_num)