On 2020/7/28 上午12:03, Michael S. Tsirkin wrote:
free cmd id is read using virtio endian, spec says all fields
in balloon are LE. Fix it up.
Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/virtio/virtio_balloon.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 774deb65a9bb..798ec304fe3e 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -578,10 +578,14 @@ static int init_vqs(struct virtio_balloon *vb)
static u32 virtio_balloon_cmd_id_received(struct virtio_balloon *vb)
{
if (test_and_clear_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
- &vb->config_read_bitmap))
+ &vb->config_read_bitmap)) {
virtio_cread(vb->vdev, struct virtio_balloon_config,
free_page_hint_cmd_id,
&vb->cmd_id_received_cache);
+ /* Legacy balloon config space is LE, unlike all other devices. */
+ if (!virtio_has_feature(vb->vdev, VIRTIO_F_VERSION_1))
+ vb->cmd_id_received_cache = le32_to_cpu((__force __le32)vb->cmd_id_received_cache);
+ }
return vb->cmd_id_received_cache;
}
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
