From 8256460e42d7eec05ff07f86c2e4cb6b5c603b81 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Tue, 25 Feb 2020 06:17:30 +0800 Subject: [PATCH 0862/2944] virtio-balloon: pull page poisoning config out of free page hinting to #26589565 Currently the page poisoning setting wasn't being enabled unless free page hinting was enabled. However we will need the page poisoning tracking logic as well for free page reporting. As such pull it out and make it a separate bit of config in the probe function. In addition we need to add support for the more recent init_on_free feature which expects a behavior similar to page poisoning in that we expect the page to be pre-zeroed. Link: http://lkml.kernel.org/r/20200211224646.29318.695.stgit@localhost.localdomain Signed-off-by: Alexander Duyck Acked-by: Michael S. Tsirkin Reviewed-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Dan Williams Cc: Dave Hansen Cc: Konrad Rzeszutek Wilk Cc: Luiz Capitulino Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko Cc: Nitesh Narayan Lal Cc: Oscar Salvador Cc: Pankaj Gupta Cc: Paolo Bonzini Cc: Rik van Riel Cc: Vlastimil Babka Cc: Wei Wang Cc: Yang Zhang Cc: wei qi Signed-off-by: Andrew Morton Signed-off-by: Stephen Rothwell Signed-off-by: Yang Shi Reviewed-by: Xunlei Pang Signed-off-by: Shile Zhang --- drivers/virtio/virtio_balloon.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 44afd1d..b7ec209 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -836,7 +836,6 @@ 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) { @@ -904,11 +903,19 @@ 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); - } + } + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { + /* Start with poison val of 0 representing general init */ + __u32 poison_val = 0; + + /* + * Let the hypervisor know that we are expecting a + * specific value to be written back in balloon pages. + */ + 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 @@ -1013,7 +1020,9 @@ static int virtballoon_restore(struct virtio_device *vdev) static int virtballoon_validate(struct virtio_device *vdev) { - if (!page_poisoning_enabled()) + /* Tell the host whether we care about poisoned pages. */ + if ((IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) || + !page_poisoning_enabled())) __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON); __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM); -- 1.8.3.1