[PATCH v33 4/4] virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON
From: Wei Wang <hidden>
Date: 2018-06-15 04:43:13
Subsystem:
the rest, virtio balloon, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", David Hildenbrand, Jason Wang
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 <redacted> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> --- drivers/virtio/virtio_balloon.c | 10 ++++++++++ include/uapi/linux/virtio_balloon.h | 3 +++ 2 files changed, 13 insertions(+)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 582a03b..c59bb380 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c@@ -634,6 +634,7 @@ static struct file_system_type balloon_fs = { static int virtballoon_probe(struct virtio_device *vdev) { struct virtio_balloon *vb; + __u32 poison_val; int err; if (!vdev->config->get) {
@@ -671,6 +672,11 @@ static int virtballoon_probe(struct virtio_device *vdev) goto out_del_vqs; } INIT_WORK(&vb->report_free_page_work, report_free_page_func); + 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); + } vb->hints = kmalloc(FREE_PAGE_HINT_MEM_SIZE, GFP_KERNEL); if (!vb->hints) { err = -ENOMEM;
@@ -796,6 +802,9 @@ 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; }
@@ -805,6 +814,7 @@ 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 99b8416..f3b6191 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
@@ -47,6 +48,8 @@ struct virtio_balloon_config { __u32 actual; /* Command sent from host */ __u32 host_cmd; + /* Stores PAGE_POISON if page poisoning is in use */ + __u32 poison_val; }; struct virtio_balloon_free_page_hints {
--
2.7.4