From 2e991629bcf55a43681aec1ee096eeb03cf81709 Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Mon, 27 Aug 2018 09:32:19 +0800 Subject: virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON The VIRTIO_BALLOON_F_PAGE_POISON feature bit is used to indicate if the guest is using page poisoning. Guest writes to the poison_val config field to tell host about the page poisoning value that is in use. Suggested-by: Michael S. Tsirkin Signed-off-by: Wei Wang Cc: Michael S. Tsirkin Cc: Michal Hocko Cc: Andrew Morton Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_balloon.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/virtio/virtio_balloon.c') diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index a18567889289..728ecd1eea30 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -825,6 +825,7 @@ static int virtio_balloon_register_shrinker(struct virtio_balloon *vb) static int virtballoon_probe(struct virtio_device *vdev) { struct virtio_balloon *vb; + __u32 poison_val; int err; if (!vdev->config->get) { @@ -892,6 +893,11 @@ static int virtballoon_probe(struct virtio_device *vdev) vb->num_free_page_blocks = 0; spin_lock_init(&vb->free_page_list_lock); INIT_LIST_HEAD(&vb->free_page_list); + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { + memset(&poison_val, PAGE_POISON, sizeof(poison_val)); + virtio_cwrite(vb->vdev, struct virtio_balloon_config, + poison_val, &poison_val); + } } /* * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a @@ -992,6 +998,9 @@ static int virtballoon_restore(struct virtio_device *vdev) static int virtballoon_validate(struct virtio_device *vdev) { + if (!page_poisoning_enabled()) + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON); + __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM); return 0; } @@ -1001,6 +1010,7 @@ static unsigned int features[] = { VIRTIO_BALLOON_F_STATS_VQ, VIRTIO_BALLOON_F_DEFLATE_ON_OOM, VIRTIO_BALLOON_F_FREE_PAGE_HINT, + VIRTIO_BALLOON_F_PAGE_POISON, }; static struct virtio_driver virtio_balloon_driver = { -- cgit v1.2.3-59-g8ed1b