virtio: change config to guest endian.

A recent proposed feature addition to the virtio block driver revealed
some flaws in the API, in particular how easy it is to break big
endian machines.

The virtio config space was originally chosen to be little-endian,
because we thought the config might be part of the PCI config space
for virtio_pci.  It's actually a separate mmio region, so that
argument holds little water; as only x86 is currently using the virtio
mechanism, we can change this (but must do so now, before the
impending s390 merge).

API changes:
- __virtio_config_val() just becomes a striaght vdev->config_get() call.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 0b3efc3..fef88d8 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -155,9 +155,9 @@ static void virtballoon_changed(struct virtio_device *vdev)
 static inline s64 towards_target(struct virtio_balloon *vb)
 {
 	u32 v;
-	__virtio_config_val(vb->vdev,
-			    offsetof(struct virtio_balloon_config, num_pages),
-			    &v);
+	vb->vdev->config->get(vb->vdev,
+			      offsetof(struct virtio_balloon_config, num_pages),
+			      &v, sizeof(v));
 	return v - vb->num_pages;
 }