The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Thanks, Sasha

------------------ original commit in Linus's tree ------------------

From 310227f42882c52356b523e2f4e11690eebcd2ab Mon Sep 17 00:00:00 2001 From: David Hildenbrand david@redhat.com Date: Tue, 13 Feb 2024 14:54:25 +0100 Subject: [PATCH] virtio: reenable config if freezing device failed

Currently, we don't reenable the config if freezing the device failed.

For example, virtio-mem currently doesn't support suspend+resume, and trying to freeze the device will always fail. Afterwards, the device will no longer respond to resize requests, because it won't get notified about config changes.

Let's fix this by re-enabling the config if freezing fails.

Fixes: 22b7050a024d ("virtio: defer config changed notifications") Cc: stable@kernel.org Cc: "Michael S. Tsirkin" mst@redhat.com Cc: Jason Wang jasowang@redhat.com Cc: Xuan Zhuo xuanzhuo@linux.alibaba.com Signed-off-by: David Hildenbrand david@redhat.com Message-Id: 20240213135425.795001-1-david@redhat.com Signed-off-by: Michael S. Tsirkin mst@redhat.com --- drivers/virtio/virtio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index f4080692b3513..f513ee21b1c18 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -510,8 +510,10 @@ int virtio_device_freeze(struct virtio_device *dev)

if (drv && drv->freeze) { ret = drv->freeze(dev); - if (ret) + if (ret) { + virtio_config_enable(dev); return ret; + } }

if (dev->config->destroy_avq)