virtio_balloon: Fix endian bug

Although virtio config space fields are usually in guest-native endian,
the spec for the virtio balloon device explicitly states that both fields
in its config space are little-endian.

However, the current virtio_balloon driver does not have a suitable endian
swap for the 'num_pages' field, although it does have one for the 'actual'
field.  This patch corrects the bug, adding sparse annotation while we're
at it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
David Gibson 2012-04-12 15:36:34 +10:00 committed by Michael S. Tsirkin
parent c0aa3e0916
commit 1a87228f5f
1 changed files with 5 additions and 2 deletions

View File

@ -234,11 +234,14 @@ static void virtballoon_changed(struct virtio_device *vdev)
static inline s64 towards_target(struct virtio_balloon *vb)
{
u32 v;
__le32 v;
s64 target;
vb->vdev->config->get(vb->vdev,
offsetof(struct virtio_balloon_config, num_pages),
&v, sizeof(v));
return (s64)v - vb->num_pages;
target = le32_to_cpu(v);
return target - vb->num_pages;
}
static void update_balloon_size(struct virtio_balloon *vb)