queue-5.15/virtio-reenable-config-if-freezing-device-failed.patch

   1 From 310227f42882c52356b523e2f4e11690eebcd2ab Mon Sep 17 00:00:00 2001
   2 From: David Hildenbrand <david@redhat.com>
   3 Date: Tue, 13 Feb 2024 14:54:25 +0100
   4 Subject: virtio: reenable config if freezing device failed
   5
   6 From: David Hildenbrand <david@redhat.com>
   7
   8 commit 310227f42882c52356b523e2f4e11690eebcd2ab upstream.
   9
  10 Currently, we don't reenable the config if freezing the device failed.
  11
  12 For example, virtio-mem currently doesn't support suspend+resume, and
  13 trying to freeze the device will always fail. Afterwards, the device
  14 will no longer respond to resize requests, because it won't get notified
  15 about config changes.
  16
  17 Let's fix this by re-enabling the config if freezing fails.
  18
  19 Fixes: 22b7050a024d ("virtio: defer config changed notifications")
  20 Cc: <stable@kernel.org>
  21 Cc: "Michael S. Tsirkin" <mst@redhat.com>
  22 Cc: Jason Wang <jasowang@redhat.com>
  23 Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
  24 Signed-off-by: David Hildenbrand <david@redhat.com>
  25 Message-Id: <20240213135425.795001-1-david@redhat.com>
  26 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28 ---
  29  drivers/virtio/virtio.c |   10 ++++++++--
  30  1 file changed, 8 insertions(+), 2 deletions(-)
  31
  32 --- a/drivers/virtio/virtio.c
  33 +++ b/drivers/virtio/virtio.c
  34 @@ -455,13 +455,19 @@ EXPORT_SYMBOL_GPL(unregister_virtio_devi
  35  int virtio_device_freeze(struct virtio_device *dev)
  36  {
  37         struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
  38 +       int ret;
  39
  40         virtio_config_disable(dev);
  41
  42         dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
  43
  44 -       if (drv && drv->freeze)
  45 -               return drv->freeze(dev);
  46 +       if (drv && drv->freeze) {
  47 +               ret = drv->freeze(dev);
  48 +               if (ret) {
  49 +                       virtio_config_enable(dev);
  50 +                       return ret;
  51 +               }
  52 +       }
  53
  54         return 0;
  55  }