---

yaml --- r: 123979 b: refs/heads/master c: 1b4aa2f h: refs/heads/master i: 123977: 7be4378 123975: 48b3509 v: v3
git-mirror · Dec 29, 2008 · fa28b5b · fa28b5b
1 parent a772a20
commit fa28b5b
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 87c7d57c17ade5024d95b6ca0da249da49b0672a
+refs/heads/master: 1b4aa2faeca1b9922033daf2475b6fc13b0ffea6
diff --git a/trunk/drivers/virtio/virtio_balloon.c b/trunk/drivers/virtio/virtio_balloon.c
@@ -56,6 +56,15 @@ static struct virtio_device_id id_table[] = {
 	{ 0 },
 };
 
+static u32 page_to_balloon_pfn(struct page *page)
+{
+	unsigned long pfn = page_to_pfn(page);
+
+	BUILD_BUG_ON(PAGE_SHIFT < VIRTIO_BALLOON_PFN_SHIFT);
+	/* Convert pfn from Linux page size to balloon page size. */
+	return pfn >> (PAGE_SHIFT - VIRTIO_BALLOON_PFN_SHIFT);
+}
+
 static void balloon_ack(struct virtqueue *vq)
 {
 	struct virtio_balloon *vb;
@@ -99,7 +108,7 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num)
 			msleep(200);
 			break;
 		}
-		vb->pfns[vb->num_pfns] = page_to_pfn(page);
+		vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);
 		totalram_pages--;
 		vb->num_pages++;
 		list_add(&page->lru, &vb->pages);
@@ -132,7 +141,7 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
 	for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns++) {
 		page = list_first_entry(&vb->pages, struct page, lru);
 		list_del(&page->lru);
-		vb->pfns[vb->num_pfns] = page_to_pfn(page);
+		vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);
 		vb->num_pages--;
 	}
 

diff --git a/trunk/include/linux/virtio_balloon.h b/trunk/include/linux/virtio_balloon.h
@@ -10,6 +10,9 @@
 /* The feature bitmap for virtio balloon */
 #define VIRTIO_BALLOON_F_MUST_TELL_HOST	0 /* Tell before reclaiming pages */
 
+/* Size of a PFN in the balloon interface. */
+#define VIRTIO_BALLOON_PFN_SHIFT 12
+
 struct virtio_balloon_config
 {
 	/* Number of pages host wants Guest to give up. */