[PATCH AUTOSEL 5.13 07/26] virtio_pci: Support surprise removal of virtio pci device

Sasha Levin
2021-08-24T00:54:32Z

From: Parav Pandit <parav@nvidia.com>

[ Upstream commit 43bb40c5b92659966bdf4bfe584fde0a3575a049 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 222d630c41fc..b35bb2d57f62 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -576,6 +576,13 @@ 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);
+
pci_disable_sriov(pci_dev);

unregister_virtio_device(&vp_dev->vdev);
--
2.30.2