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List:       linux-stable-commits
Subject:    Patch "virtio_pci: Support surprise removal of virtio pci device" has been added to the 5.4-stable t
From:       Sasha Levin <sashal () kernel ! org>
Date:       2021-08-30 19:22:41
Message-ID: 20210830192242.C893A60F46 () mail ! kernel ! org
[Download RAW message or body]

This is a note to let you know that I've just added the patch titled

    virtio_pci: Support surprise removal of virtio pci device

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     virtio_pci-support-surprise-removal-of-virtio-pci-de.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.



commit b75e078c5507d58a68763877d2f4265ee0f3c82b
Author: Parav Pandit <parav@nvidia.com>
Date:   Wed Jul 21 17:26:48 2021 +0300

    virtio_pci: Support surprise removal of virtio pci device
    
    [ 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>

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);
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