FAILED: Patch "virtio: reenable config if freezing device failed" failed to apply to 6.1-stable tree

FAILED: Patch "virtio: reenable config if freezing device failed" failed to apply to 6.1-stable tree

[Sasha Levin]

The patch below does not apply to the 6.1-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)
-- 
2.43.0

[PATCH 6.1.y] virtio: reenable config if freezing device failed

[David Hildenbrand]

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>
(cherry picked from commit 310227f42882c52356b523e2f4e11690eebcd2ab)
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/virtio/virtio.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 828ced060742..1ef094427f29 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -489,13 +489,19 @@ EXPORT_SYMBOL_GPL(unregister_virtio_device);
 int virtio_device_freeze(struct virtio_device *dev)
 {
 	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+	int ret;
 
 	virtio_config_disable(dev);
 
 	dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
 
-	if (drv && drv->freeze)
-		return drv->freeze(dev);
+	if (drv && drv->freeze) {
+		ret = drv->freeze(dev);
+		if (ret) {
+			virtio_config_enable(dev);
+			return ret;
+		}
+	}
 
 	return 0;
 }
-- 
2.44.0

Re: [PATCH 6.1.y] virtio: reenable config if freezing device failed

[Greg KH]

On Wed, Apr 10, 2024 at 11:27:58AM +0200, David Hildenbrand wrote:
> 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>
> (cherry picked from commit 310227f42882c52356b523e2f4e11690eebcd2ab)
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  drivers/virtio/virtio.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)

All now queued up,t hanks.

greg k-h