Thu, Aug 08, 2024 at 09:51:41AM CEST, kirill.shutemov@xxxxxxxxxxxxxxx wrote:
>Hongyu reported a hang on kexec in a VM. QEMU reported invalid memory
>accesses during the hang.
>
> Invalid read at addr 0x102877002, size 2, region '(null)', reason: rejected
> Invalid write at addr 0x102877A44, size 2, region '(null)', reason: rejected
> ...
>
>It was traced down to virtio-console. Kexec works fine if virtio-console
>is not in use.
>
>Looks like virtio-console continues to write to the MMIO even after
>underlying virtio-pci device is removed.
>
>The problem can be mitigated by removing all virtio devices on virtio
>bus shutdown.
>
>Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
>Reported-by: Hongyu Ning <hongyu.ning@xxxxxxxxxxxxxxx>
Could you provide a "Fixes:" tag pointing to the commit that introduced
the bug?
>---
> drivers/virtio/virtio.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
>diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>index a9b93e99c23a..6c2f908eb22c 100644
>--- a/drivers/virtio/virtio.c
>+++ b/drivers/virtio/virtio.c
>@@ -356,6 +356,15 @@ static void virtio_dev_remove(struct device *_d)
> of_node_put(dev->dev.of_node);
> }
>
>+static void virtio_dev_shutdown(struct device *_d)
>+{
>+ struct virtio_device *dev = dev_to_virtio(_d);
>+ struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
>+
>+ if (drv && drv->remove)
>+ drv->remove(dev);
>+}
>+
> static const struct bus_type virtio_bus = {
> .name = "virtio",
> .match = virtio_dev_match,
>@@ -363,6 +372,7 @@ static const struct bus_type virtio_bus = {
> .uevent = virtio_uevent,
> .probe = virtio_dev_probe,
> .remove = virtio_dev_remove,
>+ .shutdown = virtio_dev_shutdown,
> };
>
> int __register_virtio_driver(struct virtio_driver *driver, struct module *owner)
>--
>2.43.0
>
>
