4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jan Stancek jstancek@redhat.com
commit d9e427f6ab8142d6868eb719e6a7851aafea56b6 upstream.
commit c7cdff0e8647 ("virtio_balloon: fix deadlock on OOM") changed code to increment vb->num_pfns before call to set_page_pfns(), which used to happen only after.
This patch fixes boot hang for me on ppc64le KVM guests.
Fixes: c7cdff0e8647 ("virtio_balloon: fix deadlock on OOM") Cc: Michael S. Tsirkin mst@redhat.com Cc: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Cc: Michal Hocko mhocko@suse.com Cc: Wei Wang wei.w.wang@intel.com Cc: stable@vger.kernel.org Signed-off-by: Jan Stancek jstancek@redhat.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/virtio/virtio_balloon.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -174,13 +174,12 @@ static unsigned fill_balloon(struct virt while ((page = balloon_page_pop(&pages))) { balloon_page_enqueue(&vb->vb_dev_info, page);
- vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE; - set_page_pfns(vb, vb->pfns + vb->num_pfns, page); vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) adjust_managed_page_count(page, -1); + vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE; }
num_allocated_pages = vb->num_pfns;