From df81b29c7b81b9d70ee29b7a263dd5009daa0ce4 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 15 Apr 2015 10:17:43 +0930 Subject: virtio_balloon: transitional interface Virtio 1.0 doesn't include a modern balloon device. But it's not a big change to support a transitional balloon device: this has the advantage of supporting existing drivers, transparently. Signed-off-by: Michael S. Tsirkin Acked-by: Cornelia Huck Signed-off-by: Rusty Russell --- drivers/virtio/virtio_balloon.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 6a356e344f82..82e80e034f25 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -214,8 +214,8 @@ static inline void update_stat(struct virtio_balloon *vb, int idx, u16 tag, u64 val) { BUG_ON(idx >= VIRTIO_BALLOON_S_NR); - vb->stats[idx].tag = tag; - vb->stats[idx].val = val; + vb->stats[idx].tag = cpu_to_virtio16(vb->vdev, tag); + vb->stats[idx].val = cpu_to_virtio64(vb->vdev, val); } #define pages_to_bytes(x) ((u64)(x) << PAGE_SHIFT) @@ -283,18 +283,27 @@ static void virtballoon_changed(struct virtio_device *vdev) static inline s64 towards_target(struct virtio_balloon *vb) { - __le32 v; s64 target; + u32 num_pages; - virtio_cread(vb->vdev, struct virtio_balloon_config, num_pages, &v); + virtio_cread(vb->vdev, struct virtio_balloon_config, num_pages, + &num_pages); - target = le32_to_cpu(v); + /* Legacy balloon config space is LE, unlike all other devices. */ + if (!virtio_has_feature(vb->vdev, VIRTIO_F_VERSION_1)) + num_pages = le32_to_cpu((__force __le32)num_pages); + + target = num_pages; return target - vb->num_pages; } static void update_balloon_size(struct virtio_balloon *vb) { - __le32 actual = cpu_to_le32(vb->num_pages); + u32 actual = vb->num_pages; + + /* Legacy balloon config space is LE, unlike all other devices. */ + if (!virtio_has_feature(vb->vdev, VIRTIO_F_VERSION_1)) + actual = (__force u32)cpu_to_le32(actual); virtio_cwrite(vb->vdev, struct virtio_balloon_config, actual, &actual); -- cgit v1.2.3