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authorWei Wang <wei.w.wang@intel.com>2018-08-27 09:32:19 +0800
committerMichael S. Tsirkin <mst@redhat.com>2018-10-24 20:57:55 -0400
commit2e991629bcf55a43681aec1ee096eeb03cf81709 (patch)
tree36f6f0d71fb8a41382dbbf38357a1942fd63b2db
parentd95f58f4a6ca002126c36c530fb096519c94baef (diff)
downloadlinux-2e991629bcf55a43681aec1ee096eeb03cf81709.tar.bz2
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 <mst@redhat.com> Signed-off-by: Wei Wang <wei.w.wang@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r--drivers/virtio/virtio_balloon.c10
-rw-r--r--include/uapi/linux/virtio_balloon.h3
2 files changed, 13 insertions, 0 deletions
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 = {
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index 47c9eb401c08..a1966cd7b677 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -35,6 +35,7 @@
#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
#define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */
+#define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
@@ -48,6 +49,8 @@ struct virtio_balloon_config {
__u32 actual;
/* Free page report command id, readonly by guest */
__u32 free_page_report_cmd_id;
+ /* Stores PAGE_POISON if page poisoning is in use */
+ __u32 poison_val;
};
#define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */