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
