From: Michael S. Tsirkin Date: Mon, 27 Jul 2020 16:01:27 +0000 (-0400) Subject: virtio_balloon: fix up endian-ness for free cmd id X-Git-Tag: iomap-folio-5.17-old~3599^2~1 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=168c358af2f8c5a37f8b5f877ba2cc93995606ee;p=users%2Fwilly%2Flinux.git virtio_balloon: fix up endian-ness for free cmd id 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@vger.kernel.org Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Reviewed-by: Wei Wang Acked-by: David Hildenbrand --- diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index d0fd8f8dc6ed..8be02f333b7a 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; }