From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Rak Subject: skb_warn_bad_offload warnings with FreeBSD guests Date: Fri, 22 Aug 2014 12:19:10 -0400 Message-ID: <53F76D7E.4030307@gameservers.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from mail.choopa.net ([216.155.136.52]:35543 "EHLO mail.choopa.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932098AbaHVQ1o (ORCPT ); Fri, 22 Aug 2014 12:27:44 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.choopa.net (iRedMail) with ESMTP id 1F61B4AF453 for ; Fri, 22 Aug 2014 12:19:11 -0400 (EDT) Received: from mail.choopa.net ([127.0.0.1]) by localhost (mail.choopa.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id J+1Dt7Be9OdJ for ; Fri, 22 Aug 2014 12:19:10 -0400 (EDT) Received: from [10.5.5.117] (office-nat.choopa.net [208.167.225.40]) by mail.choopa.net (iRedMail) with ESMTPSA id 9E1084AF450 for ; Fri, 22 Aug 2014 12:19:10 -0400 (EDT) Sender: netdev-owner@vger.kernel.org List-ID: We have a number of machines running qemu with bridged networking. We have noticed that *sometimes* FreeBSD guests cause this warning to flood the host "WARNING: CPU: 5 PID: 3705 at net/core/dev.c:2238 skb_warn_bad_offload+0xc3/0xd0()". I haven't been able to come up with any sort of reproduction steps, it just seems to happen to some FreeBSD guests, but not others. A full stack trace looks like this: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 7147 at net/core/dev.c:2233 skb_warn_bad_offload+0xc3/0xd0() igb: caps=(0x0000000190114bb3, 0x0000000000000000) len=2962 data_len=0 gso_size=1448 gso_type=5 ip_summed=0 Modules linked in: dm_snapshot dm_bufio ipmi_devintf xt_physdev ebt_arp ebt_ip ebtable_nat ebtables cls_fw sch_sfq sch_htb tun kvm_intel kvm 8021q garp nfnetlink_queue nfnetlink_log nfnetlink bluetooth rfkill bridge stp llc xt_CHECKSUM iptable_mangle ipt_REJECT iptable_filter ip _tables ip6t_REJECT ip6table_filter ip6_tables ipv6 iTCO_wdt iTCO_vendor_support ipmi_si ipmi_msghandler microcode pcspkr i2c_i801 joydev sg lpc_ich shpchp igb dca ptp pps_core hwmon ext4 jbd2 mbcache sd_mod crc_t10dif crct10dif_common video ahci libahci xhci_hcd ast ttm drm_kms _helper sysimgblt sysfillrect syscopyarea dm_mirror dm_region_hash dm_log dm_mod CPU: 1 PID: 7147 Comm: qemu-kvm Tainted: G W 3.15.5-1.el6.elrepo.x86_64 #1 Hardware name: Supermicro X10SLE-F/HF/X10SLE, BIOS 1.1 07/19/2013 00000000000008b9 ffff88081fc435d8 ffffffff8163ba90 00000000000008b9 ffff88081fc43628 ffff88081fc43618 ffffffff8106c30c ffffc90007a06e30 0000000000000000 ffff8807f2b64000 ffff8807f2b64000 0000000000000000 Call Trace: [] dump_stack+0x49/0x61 [] warn_slowpath_common+0x8c/0xc0 [] warn_slowpath_fmt+0x46/0x50 [] skb_warn_bad_offload+0xc3/0xd0 [] ? dev_hard_start_xmit+0x339/0x640 [] __skb_gso_segment+0x89/0xe0 [] dev_hard_start_xmit+0x186/0x640 [] sch_direct_xmit+0xfa/0x1d0 [] __dev_queue_xmit+0x1ff/0x4f0 [] dev_queue_xmit+0x10/0x20 [] br_dev_queue_push_xmit+0x82/0xb0 [bridge] [] br_nf_dev_queue_xmit+0x20/0x90 [bridge] [] br_nf_post_routing+0x2d8/0x300 [bridge] [] ? deliver_clone+0x60/0x60 [bridge] [] nf_iterate+0x8e/0xc0 [] ? deliver_clone+0x60/0x60 [bridge] [] nf_hook_slow+0x7d/0x150 [] ? deliver_clone+0x60/0x60 [bridge] [] ? br_nf_dev_queue_xmit+0x90/0x90 [bridge] [] br_forward_finish+0x43/0x60 [bridge] [] br_nf_forward_finish+0x1b8/0x1d0 [bridge] [] br_nf_forward_ip+0x3a8/0x410 [bridge] [] ? br_flood_deliver+0x20/0x20 [bridge] [] nf_iterate+0x8e/0xc0 [] ? br_flood_deliver+0x20/0x20 [bridge] [] nf_hook_slow+0x7d/0x150 [] ? br_flood_deliver+0x20/0x20 [bridge] [] __br_forward+0xa4/0x100 [bridge] [] ? NF_HOOK.clone.0+0x70/0x70 [bridge] [] br_forward+0x96/0xb0 [bridge] [] ? NF_HOOK.clone.0+0x70/0x70 [bridge] [] br_handle_frame_finish+0x197/0x3f0 [bridge] [] ? NF_HOOK.clone.0+0x70/0x70 [bridge] [] br_nf_pre_routing_finish+0x2b0/0x370 [bridge] [] ? br_nf_post_routing+0x300/0x300 [bridge] [] NF_HOOK_THRESH+0x56/0x60 [bridge] [] br_nf_pre_routing+0x2fb/0x3a0 [bridge] [] nf_iterate+0x8e/0xc0 [] ? NF_HOOK.clone.0+0x70/0x70 [bridge] [] nf_hook_slow+0x7d/0x150 [] ? NF_HOOK.clone.0+0x70/0x70 [bridge] [] br_handle_frame+0x19c/0x240 [bridge] [] ? br_handle_frame_finish+0x3f0/0x3f0 [bridge] [] __netif_receive_skb_core+0x1e5/0x620 [] __netif_receive_skb+0x27/0x70 [] process_backlog+0x103/0x200 [] net_rx_action+0x112/0x2a0 [] __do_softirq+0xfc/0x2b0 [] ? irq_exit+0xad/0xd0 [] do_softirq_own_stack+0x1c/0x30 [] do_softirq+0x55/0x60 [] netif_rx_ni+0x39/0x70 [] tun_get_user+0x310/0x6c0 [tun] [] tun_chr_aio_write+0x85/0xa0 [tun] [] do_sync_readv_writev+0x4d/0x80 [] do_readv_writev+0xc8/0x2c0 [] ? do_sync_readv_writev+0x80/0x80 [] ? poll_select_set_timeout+0x95/0xb0 [] vfs_writev+0x37/0x50 [] SyS_writev+0x56/0xf0 [] system_call_fastpath+0x16/0x1b ---[ end trace d26e70ba037ab631 ]--- gso_type=5 and ip_summed=0 are always the same (though len, data_len, and gso_size vary). What is causing this? I've tried kernels as new as 3.15.5-1, which do not appear to help.