diff mbox

[v3,07/10] virtio: use unsigned int for virtqueue_get_avail_bytes() index

Message ID 1460467534-29147-8-git-send-email-stefanha@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Stefan Hajnoczi April 12, 2016, 1:25 p.m. UTC
The virtio code uses int, unsigned int, and uint16_t for virtqueue
indices.  The uint16_t is used for the low-level descriptor layout in
virtio_ring.h while code that isn't concerned with descriptor layout can
use unsigned int.

Use of int is problematic because it can result in signed/unsigned
comparison and incompatible int*/unsigned int* pointer types.

Make the virtqueue_get_avail_bytes() 'i' variable unsigned int.  This
eliminates the need to introduce casts and modify code further in the
patches that follow.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/virtio/virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Cornelia Huck Sept. 20, 2016, 11:45 a.m. UTC | #1
On Tue, 12 Apr 2016 14:25:31 +0100
Stefan Hajnoczi <stefanha@redhat.com> wrote:

> The virtio code uses int, unsigned int, and uint16_t for virtqueue
> indices.  The uint16_t is used for the low-level descriptor layout in
> virtio_ring.h while code that isn't concerned with descriptor layout can
> use unsigned int.
> 
> Use of int is problematic because it can result in signed/unsigned
> comparison and incompatible int*/unsigned int* pointer types.
> 
> Make the virtqueue_get_avail_bytes() 'i' variable unsigned int.  This
> eliminates the need to introduce casts and modify code further in the
> patches that follow.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  hw/virtio/virtio.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff mbox

Patch

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 48f759e..493d6a7 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -392,7 +392,7 @@  void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
         unsigned int max, num_bufs, indirect = 0;
         VRingDesc desc;
         hwaddr desc_pa;
-        int i;
+        unsigned int i;
 
         max = vq->vring.num;
         num_bufs = total_bufs;