RE: [Xen-users] Xen Windows Clients - BSOD withApplicationFirewallInstalls

[<xensource.2007@xxxxxxxxxxxxxxxxx>]

Hi James
Thanks for the detailed instructions.
There are 2 VMs that use this bridge (2000 svr and xp sp2), but it makes no 
difference to the bsod if 1 or both are running. With
both running the xp tap is tap1, otherwise it's tap0.
When I do the tcdump it shows only packets that seem to relate to the ssh 
session to DOM0 (The ssh port is 22716, DOM0 is
192.168.20.7 and machine I am ssh from is 192.168.20.30), then it bsods. Before 
the bsod there is some double size packets. (Even
though I have disabled gso on all interfaces, bridges and otherwise), but not 
directly prior to the bsod. So at this stage I am not
sure if I'm down the garden path or still on the verandah. :-)
The physical interface that the packets run on is eth1. I am a little confused 
as to why the ssh packets also show up on the tap1
interface as there is no ssh connection to the DOMU, only DOM0.
Thanks. The dump is below:
---------------------------------------------------------------------------
# tcpdump -i tap0 greater 1500
tcpdump: WARNING: tap0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap0, link-type EN10MB (Ethernet), capture size 96 bytes
20:44:42.183259 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
2964273857:2964275317(1460) ack 3005185253 win 545
20:44:43.626964 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
7296:8756(1460) ack 417 win 545
20:44:43.626980 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
8756:10216(1460) ack 417 win 545
20:44:44.266984 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
12784:15704(2920) ack 449 win 545
20:44:45.225979 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
16912:18372(1460) ack 449 win 545
20:44:46.178139 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
20272:21732(1460) ack 449 win 545
20:44:46.576267 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
23824:25284(1460) ack 529 win 545
20:44:46.577062 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
25888:27348(1460) ack 529 win 545
20:44:46.585779 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
27348:28808(1460) ack 529 win 545
20:44:47.178179 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
30160:33080(2920) ack 609 win 545
20:44:47.885066 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
35712:37172(1460) ack 609 win 545
20:44:47.885997 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
37776:39236(1460) ack 609 win 545
20:44:47.893317 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
39236:40696(1460) ack 609 win 545
20:44:48.182306 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
41520:44440(2920) ack 641 win 545
20:44:48.182329 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: P 
44440:45888(1448) ack 641 win 545
20:44:48.191866 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
47248:48708(1460) ack 641 win 545
20:44:48.234170 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
50192:51652(1460) ack 721 win 545
20:44:48.407627 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
52912:54372(1460) ack 721 win 545
20:44:48.408410 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
54960:56420(1460) ack 721 win 545
20:44:48.409493 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
56800:58260(1460) ack 721 win 545
20:44:48.571215 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
58608:60068(1460) ack 753 win 545
20:44:48.600938 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
60496:61956(1460) ack 801 win 545
20:44:48.601814 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
62336:63796(1460) ack 801 win 545
20:44:48.715526 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
64384:65844(1460) ack 801 win 545
20:44:48.716277 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
66416:67876(1460) ack 801 win 545
20:44:48.717355 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
68256:69716(1460) ack 801 win 545
20:44:49.182112 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
70304:73224(2920) ack 833 win 545
20:44:49.182136 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
73224:74684(1460) ack 833 win 545
20:44:50.182639 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
76720:78180(1460) ack 833 win 545
20:44:50.182659 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
78180:79640(1460) ack 833 win 545
20:44:50.188947 IP 192.168.20.7.22716 > 192.168.20.30.kofax-svr: . 
79872:81332(1460) ack 833 win 545
tcpdump: pcap_loop: recvfrom: Network is down
31 packets captured
66 packets received by filter
0 packets dropped by kernel
[root@catss3 vm]# Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/console.py", line 202, in 
_vnc_disconnected
    self.try_login()
  File "/usr/share/virt-manager/virtManager/console.py", line 217, in try_login
    protocol, host, port = self.vm.get_graphics_console()
  File "/usr/share/virt-manager/virtManager/domain.py", line 447, in 
get_graphics_console
    type = self.get_xml_string("/domain/devices/graphics/@type")
  File "/usr/share/virt-manager/virtManager/domain.py", line 417, in 
get_xml_string
    xml = self.get_xml()
  File "/usr/share/virt-manager/virtManager/domain.py", line 51, in get_xml
    self.xml = self.vm.XMLDesc(0)
  File "/usr/lib64/python2.4/site-packages/libvirt.py", line 196, in XMLDesc
    if ret is None: raise libvirtError ('virDomainGetXMLDesc() failed', 
dom=self)
libvirt.libvirtError: virDomainGetXMLDesc() failed
----------------------------------------------------------------------------------
-----Original Message-----
From: James Harper [mailto:james.harper@xxxxxxxxxxxxxxxx] 
Sent: Tuesday, 25 March 2008 5:55 PM
To: xensource.2007@xxxxxxxxxxxxxxxxx; xen-users@xxxxxxxxxxxxxxxxxxx
Subject: RE: [Xen-users] Xen Windows Clients - BSOD 
withApplicationFirewallInstalls


I think you'll need to figure out what interface is launching these packets 
onto your network, but in the meantime just turn of gso
on all interfaces attached to the bridge - do a 'brctl show' to get a list of 
them.

If you are still getting BSoD's after doing that, do a tcpdump on the tapX 
device belonging to your windows HVM domain, and see if a
large packet coincides with your BSoD. If it doesn't, then I've probably lead 
you down the wrong path.

It might be easiest to do that second step first:
. brctl show
. create your domain in a paused state
. brctl show
. start a tcpdump on your tapX interface (eg the one that wasn't there in the 
first brctl show but is in the second). If this is
your only hvm domain then you can skip this and just assume tap0

The syntax you want for your tcpdump is probably something like 'tcpdump -i 
tapX greater 1500', which should be fired whenever a
packet is >1500 bytes.

James

> -----Original Message-----
> From: DoNotReply [mailto:DoNotReply@xxxxxxxxxxxxxxxxx] On Behalf Of 
> xensource.2007@xxxxxxxxxxxxxxxxx
> Sent: Tuesday, 25 March 2008 18:36
> To: James Harper; xensource.2007@xxxxxxxxxxxxxxxxx; xen- 
> users@xxxxxxxxxxxxxxxxxxx
> Subject: RE: [Xen-users] Xen Windows Clients - BSOD 
> withApplicationFirewallInstalls
> 
> Thanks James
> But it makes no dif. Am I applying it to the correct interface
(xenbr1)?
> 
> 
> -----Original Message-----
> From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx [mailto:xen-users- 
> bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of James Harper
> Sent: Monday, 24 March 2008 6:49 PM
> To: xensource.2007@xxxxxxxxxxxxxxxxx; Rudi Ahlers; xen- 
> users@xxxxxxxxxxxxxxxxxxx
> Subject: RE: [Xen-users] Xen Windows Clients - BSOD 
> withApplicationFirewallInstalls
> 
> 
> > 6) At firewall startup, BSOD
> > 7) Subsequent restarts result in BSOD as previously stated.
> 
> Xen appears to be sending 'large' packets onto the bridge, and the tap 
> interface isn't 'un-large-ing' them.
> 
> "
> 20:40:34.437312 IP (tos 0x0, ttl 128, id 34470, offset 0, flags [DF],
> proto: TCP (6), length: 52) 192.168.207.200.5001 >
> 192.168.207.254.53981: ., cksum 0x05aa (correct), 1:1(0) ack 14505 win 
> 58295 <nop,nop,timestamp 57828874 1445680997> 20:40:34.437324 IP (tos 
> 0x0, ttl  64, id 51510, offset 0, flags [DF],
> proto: TCP (6), length: 4396) 192.168.207.254.53981 >
> 192.168.207.200.5001: . 23193:27537(4344) ack 1 win 46
<nop,nop,timestamp
> 1445680998 57828874> 20:40:34.439653 IP (tos 0x0, ttl 128,
> id 34471, offset 0, flags [DF],
> proto: TCP (6), length: 64) 192.168.207.200.5001 >
> 192.168.207.254.53981: ., cksum 0x2a79 (correct), 1:1(0) ack 15953 win 
> 56847 <nop,nop,timestamp 57828874 1445680997,nop,nop,sack 1 
> {17401:18849}> 20:40:34.439670 IP (tos 0x0, ttl  64, id 51513, offset
0,
> flags [DF],
> proto: TCP (6), length: 4396) 192.168.207.254.53981 >
> 192.168.207.200.5001: . 27537:31881(4344) ack 1 win 46
<nop,nop,timestamp
> 1445680999 57828874> "
> 
> Note the lengh of 4396 - the hardware interface is supposed to break
that
> up into MSS sized chunks, but there is no hardware
> interface involved in this case.
> 
> I'm trying to resolve the problem in the GPL PV drivers.
> 
> I've had wireshark (npf.sys) BSOD when it receives a packet with a
size
> greater than MTU, so I imagine a firewall may well do the same thing.
> 
> Try turning off large send offload for all interfaces on the bridge
(the
> same bridge as your crashing DomU), eg:
> 
> "
> ethtool -K <ifname> gso off
> "
> 
> Iperf gives horrible results too when DomU is the 'server' and Dom0 is
the
> 'client' because of this.
> 
> James
> 
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-users
> 
> No virus found in this incoming message.
> Checked by AVG.
> Version: 7.5.519 / Virus Database: 269.22.0/1341 - Release Date: 
> 24/03/2008 3:03 PM
> 
> No virus found in this outgoing message.
> Checked by AVG.
> Version: 7.5.519 / Virus Database: 269.22.0/1341 - Release Date: 
> 24/03/2008 3:03 PM
> 
> 


No virus found in this incoming message.
Checked by AVG. 
Version: 7.5.519 / Virus Database: 269.22.0/1341 - Release Date: 24/03/2008 
3:03 PM

No virus found in this outgoing message.
Checked by AVG. 
Version: 7.5.519 / Virus Database: 269.22.0/1341 - Release Date: 24/03/2008 
3:03 PM
 



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