[PATCH 4.6 113/203] virtio_balloon: fix PFN format for virtio-1

Greg Kroah-Hartman
2016-07-25T21:55:09Z

From: Michael S. Tsirkin <mst@redhat.com>

commit 87c9403b0d1de4676b0bd273eea68fcf6de68e68 upstream.

Everything should be LE when using virtio-1, but
the linux balloon driver does not seem to care about that.

Reported-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/virtio/virtio_balloon.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

--- 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_ball

}

-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 virt
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 virt
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 virt
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(struc
__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);