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> --- 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