4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jan Stancek <[email protected]> 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 <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Wei Wang <[email protected]> Cc: [email protected] Signed-off-by: Jan Stancek <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Sudip Mukherjee <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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;
