virtio-balloon: process all in sgs for free_page_vq

We only process the first in sg which may lead to the bitmap of the
pages belongs to following sgs were not cleared. This may result more
pages to be migrated. Fixing this by process all in sgs for
free_page_vq.

Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211129030841.3611-1-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index c6962fcbfe5beac4aa7509c35068358f0bc3e80f..17de2558cbb9ae07b4f085939988b10b0e08a804 100644 (file)
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -510,6 +510,7 @@ static bool get_free_page_hints(VirtIOBalloon *dev)
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtQueue *vq = dev->free_page_vq;
     bool ret = true;
+    int i;
 
     while (dev->block_iothread) {
         qemu_cond_wait(&dev->free_page_cond, &dev->free_page_lock);
@@ -544,8 +545,10 @@ static bool get_free_page_hints(VirtIOBalloon *dev)
     }
 
     if (elem->in_num && dev->free_page_hint_status == FREE_PAGE_HINT_S_START) {
-        qemu_guest_free_page_hint(elem->in_sg[0].iov_base,
-                                  elem->in_sg[0].iov_len);
+        for (i = 0; i < elem->in_num; i++) {
+            qemu_guest_free_page_hint(elem->in_sg[i].iov_base,
+                                      elem->in_sg[i].iov_len);
+        }
     }
 
 out: