This is a note to let you know that I've just added the patch titled virtio_balloon: disable VIOMMU support to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: virtio_balloon-disable-viommu-support.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e41b1355508debe45fda33ef8c03ff3ba5d206b9 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Date: Tue, 13 Jun 2017 20:56:44 +0300 Subject: virtio_balloon: disable VIOMMU support From: Michael S. Tsirkin <mst@xxxxxxxxxx> commit e41b1355508debe45fda33ef8c03ff3ba5d206b9 upstream. virtio balloon bypasses the DMA API entirely so does not support the VIOMMU right now. It's not clear we need that support, for now let's just make sure we don't pretend to support it. Cc: Wei Wang <wei.w.wang@xxxxxxxxx> Fixes: 1a937693993f ("virtio: new feature to detect IOMMU device quirk") Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/virtio/virtio_balloon.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -657,6 +657,12 @@ static int virtballoon_restore(struct vi } #endif +static int virtballoon_validate(struct virtio_device *vdev) +{ + __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM); + return 0; +} + static unsigned int features[] = { VIRTIO_BALLOON_F_MUST_TELL_HOST, VIRTIO_BALLOON_F_STATS_VQ, @@ -669,6 +675,7 @@ static struct virtio_driver virtio_ballo .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, + .validate = virtballoon_validate, .probe = virtballoon_probe, .remove = virtballoon_remove, .config_changed = virtballoon_changed, Patches currently in stable-queue which might be from mst@xxxxxxxxxx are queue-4.9/virtio_balloon-disable-viommu-support.patch