From: Parav Pandit parav@nvidia.com

commit 43bb40c5b92659966bdf4bfe584fde0a3575a049 upstream.

When a virtio pci device undergo surprise removal (aka async removal in PCIe spec), mark the device as broken so that any upper layer drivers can abort any outstanding operation.

When a virtio net pci device undergo surprise removal which is used by a NetworkManager, a below call trace was observed.

kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/1:1:27059] watchdog: BUG: soft lockup - CPU#1 stuck for 52s! [kworker/1:1:27059] CPU: 1 PID: 27059 Comm: kworker/1:1 Tainted: G S W I L 5.13.0-hotplug+ #8 Hardware name: Dell Inc. PowerEdge R640/0H28RR, BIOS 2.9.4 11/06/2020 Workqueue: events linkwatch_event RIP: 0010:virtnet_send_command+0xfc/0x150 [virtio_net] Call Trace: virtnet_set_rx_mode+0xcf/0x2a7 [virtio_net] ? __hw_addr_create_ex+0x85/0xc0 __dev_mc_add+0x72/0x80 igmp6_group_added+0xa7/0xd0 ipv6_mc_up+0x3c/0x60 ipv6_find_idev+0x36/0x80 addrconf_add_dev+0x1e/0xa0 addrconf_dev_config+0x71/0x130 addrconf_notify+0x1f5/0xb40 ? rtnl_is_locked+0x11/0x20 ? __switch_to_asm+0x42/0x70 ? finish_task_switch+0xaf/0x2c0 ? raw_notifier_call_chain+0x3e/0x50 raw_notifier_call_chain+0x3e/0x50 netdev_state_change+0x67/0x90 linkwatch_do_dev+0x3c/0x50 __linkwatch_run_queue+0xd2/0x220 linkwatch_event+0x21/0x30 process_one_work+0x1c8/0x370 worker_thread+0x30/0x380 ? process_one_work+0x370/0x370 kthread+0x118/0x140 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30

Hence, add the ability to abort the command on surprise removal which prevents infinite loop and system lockup.

Signed-off-by: Parav Pandit parav@nvidia.com Link: https://lore.kernel.org/r/20210721142648.1525924-5-parav@nvidia.com Signed-off-by: Michael S. Tsirkin mst@redhat.com --- drivers/virtio/virtio_pci_common.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index 80a3704939cd..b9c06885de6a 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -575,6 +575,13 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); struct device *dev = get_device(&vp_dev->vdev.dev);

+ /* + * Device is marked broken on surprise removal so that virtio upper + * layers can abort any ongoing operation. + */ + if (!pci_device_is_present(pci_dev)) + virtio_break_device(&vp_dev->vdev); + unregister_virtio_device(&vp_dev->vdev);

if (vp_dev->ioaddr)