Re: PROBLEM: virtio_net LRO kernel panics

From: "Michael S. Tsirkin" <mst@redhat.com>
To: Ivan <ivan@prestigetransportation.com>
Cc: Jason Wang <jasowang@redhat.com>,
	Willem de Bruijn <willemb@google.com>,
	"David S. Miller" <davem@davemloft.net>,
	Tonghao Zhang <xiangxia.m.yue@gmail.com>,
	virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>
Subject: Re: PROBLEM: virtio_net LRO kernel panics
Date: Sat, 31 Jul 2021 16:53:01 -0400	[thread overview]
Message-ID: <20210731165155-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <CACFia2d82tqUrLwpt0fowm3DpD7+HXM9Vcfz56eQ_AkTcWmOEg@mail.gmail.com>

On Fri, Jul 30, 2021 at 12:04:18PM -0500, Ivan wrote:
> 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.

So the host or to the guest? 

-- 
MST