Re: PROBLEM: virtio_net LRO kernel panics

[Ivan <ivan@prestigetransportation.com>]

On Sun, Aug 1, 2021 at 11:35 PM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2021/7/31 上午1:04, Ivan 写道:
> > On Fri, Jul 30, 2021 at 6:42 AM Michael S. Tsirkin <mst@redhat.com> wrote:
> >> On Thu, Jul 22, 2021 at 06:27:18PM -0500, Ivan wrote:
> >>> Dear Sir,
> >>>
> >>> I've been plagued with kernel panics recently. The problem is easily
> >>> reproducible on any virtual machine that uses the virtio-net driver
> >>> from stock Linux kernel. Simply isuse this command:
> >>>
> >>> echo 1 > /proc/sys/net/ipv4/ip_forward
> >>> ...and the kernel panics.
> >>>
> >>> Is there any way we can possibly fix this?
> >>>
> >>> kernel: ------------[ cut here ]------------
> >>> kernel: netdevice: eth0: failed to disable LRO!
> >>> kernel: WARNING: CPU: 1 PID: 424 at net/core/dev.c:1768
> >>> dev_disable_lro+0x108/0x150
> >>> kernel: Modules linked in: nls_iso8859_1 nls_cp437 vfat fat usbhid
> >>> atkbd libps2 ahci libahci virtio_net ohci_pci net_failover failover
> >>> i8042 serio lpc_ich mfd_core libata ohci_hcd ehci_pci ehci_hcd usbcore
> >>> rng_core i2c_piix4 i2c_core virtio_pci usb_common
> >>> virtio_pci_modern_dev virtio_ring virtio loop unix
> >>> kernel: CPU: 1 PID: 424 Comm: bash Not tainted 5.13.4-gnu.4-NuMini #1
> >>> kernel: Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
> >>> VirtualBox 12/01/2006
> >>> kernel: RIP: 0010:dev_disable_lro+0x108/0x150
> >>> kernel: Code: ae 88 74 14 be 25 00 00 00 48 89 df e8 f1 54 ed ff 48 85
> >>> c0 48 0f 44 eb 4c 89 e2 48 89 ee 48 c7 c7 00 c6 ae 88 e8 7a 76 0c 00
> >>> <0f> 0b e9 2d ff ff ff 80 3d e8 70 97 00 00 49 c7 c4 73 bb ae 88 75
> >>> kernel: RSP: 0018:ffffb596c0237d80 EFLAGS: 00010282
> >>> kernel: RAX: 0000000000000000 RBX: ffff9af9c1835000 RCX: ffff9af9fed17538
> >>> kernel: RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9af9fed17530
> >>> kernel: RBP: ffff9af9c1835000 R08: ffffffff88c96ac8 R09: 0000000000004ffb
> >>> kernel: R10: 00000000fffff000 R11: 3fffffffffffffff R12: ffffffff88ac7c3d
> >>> kernel: R13: 0000000000000000 R14: ffffffff88cb2748 R15: ffff9af9c12166c8
> >>> kernel: FS:  00007fd4911b8740(0000) GS:ffff9af9fed00000(0000)
> >>> knlGS:0000000000000000
> >>> kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >>> kernel: CR2: 0000000000532008 CR3: 000000000115c000 CR4: 00000000000406e0
> >>> kernel: Call Trace:
> >>> kernel:  devinet_sysctl_forward+0x1ac/0x1e0
> >>> kernel:  proc_sys_call_handler+0x127/0x230
> >>> kernel:  new_sync_write+0x114/0x1a0
> >>> kernel:  vfs_write+0x18c/0x220
> >>> kernel:  ksys_write+0x5a/0xd0
> >>> kernel:  do_syscall_64+0x45/0x80
> >>> kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xae
> >>> kernel: RIP: 0033:0x7fd4912b79b3
> >>> kernel: Code: 8b 15 b9 74 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb
> >>> b7 0f 1f 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05
> >>> <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18
> >>> kernel: RSP: 002b:00007ffe96fdd858 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> >>> kernel: RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd4912b79b3
> >>> kernel: RDX: 0000000000000002 RSI: 0000000000536810 RDI: 0000000000000001
> >>> kernel: RBP: 0000000000536810 R08: 000000000000000a R09: 0000000000000000
> >>> kernel: R10: 00007fd49134f040 R11: 0000000000000246 R12: 0000000000000002
> >>> kernel: R13: 00007fd4913906c0 R14: 00007fd49138c520 R15: 00007fd49138b920
> >>> kernel: ---[ end trace ee7985b10570603d ]---
> >>> kernel: ------------[ cut here ]------------
> >> So the warning is easy to reproduce.
> >> On qemu/kvm just set ctrl_guest_offloads=off for the device.
> > I have no control over the settings of the host.
> > I have full control over the guest.
> >
> >> The panic does not seem to trigger for me and you did not provide
> >> any data about it.  What happens? Does guest just freeze?
> > I'm not sure if I am misusing the word "panic". (Appologies, not a programer)
> > No, the guest does not freeze, just, the moment I issue the command...
> >    echo 1 > /proc/sys/net/ipv4/ip_forward
> > ... and I see the "--[ cut here ]--" message appear in the syslog.
> > Shortly thereafter my ssh session to that host dies.
>
>
> Does it work before this commit?
>
> commit a02e8964eaf9271a8a5fcc0c55bd13f933bafc56
> Author: Willem de Bruijn <willemb@google.com>
> Date:   Thu Dec 20 17:14:54 2018 -0500
>
>      virtio-net: ethtool configurable LRO

Yes.