Re: [PATCH] virtio_balloon: fix PFN format for virtio-1

From: Michael S. Tsirkin
Date: Mon Jun 13 2016 - 14:08:53 EST


On Wed, May 18, 2016 at 03:38:53PM +0300, Michael S. Tsirkin wrote:
> Everything should be LE when using virtio-1, but
> the linux balloon driver does not seem to care about that.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

Forgot to CC stable.
Please consider this patch for inclusion in the next stable Linux.


> ---
> drivers/virtio/virtio_balloon.c | 20 ++++++++++++--------
> 1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 7b6d74f..476c0e3 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -75,7 +75,7 @@ struct virtio_balloon {
>
> /* The array of pfns we tell the Host about. */
> unsigned int num_pfns;
> - u32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX];
> + __virtio32 pfns[VIRTIO_BALLOON_ARRAY_PFNS_MAX];
>
> /* Memory statistics */
> struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR];
> @@ -127,14 +127,16 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
>
> }
>
> -static void set_page_pfns(u32 pfns[], struct page *page)
> +static void set_page_pfns(struct virtio_balloon *vb,
> + __virtio32 pfns[], struct page *page)
> {
> unsigned int i;
>
> /* Set balloon pfns pointing at this page.
> * Note that the first pfn points at start of the page. */
> for (i = 0; i < VIRTIO_BALLOON_PAGES_PER_PAGE; i++)
> - pfns[i] = page_to_balloon_pfn(page) + i;
> + pfns[i] = cpu_to_virtio32(vb->vdev,
> + page_to_balloon_pfn(page) + i);
> }
>
> static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
> @@ -158,7 +160,7 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
> msleep(200);
> break;
> }
> - set_page_pfns(vb->pfns + vb->num_pfns, 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))
> @@ -177,10 +179,12 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
> static void release_pages_balloon(struct virtio_balloon *vb)
> {
> unsigned int i;
> + struct page *page;
>
> /* Find pfns pointing at start of each page, get pages and free them. */
> for (i = 0; i < vb->num_pfns; i += VIRTIO_BALLOON_PAGES_PER_PAGE) {
> - struct page *page = balloon_pfn_to_page(vb->pfns[i]);
> + page = balloon_pfn_to_page(virtio32_to_cpu(vb->vdev,
> + vb->pfns[i]));
> if (!virtio_has_feature(vb->vdev,
> VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
> adjust_managed_page_count(page, 1);
> @@ -203,7 +207,7 @@ static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
> page = balloon_page_dequeue(vb_dev_info);
> if (!page)
> break;
> - set_page_pfns(vb->pfns + vb->num_pfns, page);
> + set_page_pfns(vb, vb->pfns + vb->num_pfns, page);
> vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE;
> }
>
> @@ -471,13 +475,13 @@ static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,
> __count_vm_event(BALLOON_MIGRATE);
> spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags);
> vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE;
> - set_page_pfns(vb->pfns, newpage);
> + set_page_pfns(vb, vb->pfns, newpage);
> tell_host(vb, vb->inflate_vq);
>
> /* balloon's page migration 2nd step -- deflate "page" */
> balloon_page_delete(page);
> vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE;
> - set_page_pfns(vb->pfns, page);
> + set_page_pfns(vb, vb->pfns, page);
> tell_host(vb, vb->deflate_vq);
>
> mutex_unlock(&vb->balloon_lock);
> --
> MST