port-xen/44743: Network doesn't work on DomU NetBSD 5.1 which is run on Debian Squeeze Dom0 (Xen 4)

[bbartlomiej%gmail.com@localhost]

>Number:         44743
>Category:       port-xen
>Synopsis:       Network doesn't work on DomU NetBSD 5.1 which is run on Debian 
>Squeeze Dom0 (Xen 4)
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 19 16:15:00 +0000 2011
>Originator:     Bartek Krawczyk
>Release:        5.1
>Organization:
>Environment:
NetBSD 5.1 netbsd-INSTALL_XEN3PAE_DOMU.gz
>Description:
Hi!
I've upgraded a Xen dom0 server from debian lenny (linux 2.6.26-i386) to 
squeeze (linux 2.6.32-5 with pvops, Xen 4) and can't netinstall a NetBSD 5.1 
DomU. The network under netbsd domu just isn't working (other Linux DomUs work 
just fine). The vif on dom0 is created correctly (through network-bridge script 
from /etc/xen), the xennet0 is recognized in the 
netbsd-INSTALL_XEN3PAE_DOMU.gz, I can add an IP address to it and ping it (and 
127.0.0.1) but nothing more. I've read that there was some problems with 
flip/copy mode on Xen 4 but it was fixed in 5.1 (according to CHANGELOG).

# ifconfig xennet0
xennet0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        capabilities=2800<TCP4CSUM_Tx,UDP4CSUM_Tx>
        enabled=0
        address: 00:16:3e:28:7c:a1
        inet 88.199.21.14 netmask 0xffffffe0 broadcast 88.199.21.31
        inet6 fe80::216:3eff:fe28:7ca1%xennet0 prefixlen 64 scopeid 0x1
dmesg:
xennet0 at xenbus0 id 0: Xen Virtual Network Interface
xennet0: MAC address 00:16:3e:28:7c:a1
xennet0: using event channel 7

xen:/etc/xen/scripts# brctl show
bridge name     bridge id               STP enabled     interfaces
eth0            8000.001422095e63       no              peth0
                                                        vif1.0
                                                        vif2.0
                                                        vif3.0
                                                        vif4.0
                                                        vif5.0
                                                        vif7.0
eth1            8000.001422095e64       no              peth1
                                                        vif4.1

there's also a warning in the netbsd dmesg:
WARNING: clock gained 132 days
WARNING: CHECK AND RESET THE DATE!
(and the timezone can't be set from the installer, it's UTC where it should be 
UTC+1)

xen:/etc/xen/scripts# xm network-list 7
Idx BE     MAC Addr.     handle state evt-ch tx-/rx-ring-ref BE-path
0   0  00:16:3e:28:7c:a1    0     4      7     509  /508     
/local/domain/0/backend/vif/7/0  

xen:/etc/xen/scripts# xm network-list 7 -l
(0
    ((mac 00:16:3e:28:7c:a1)
        (handle 0)
        (protocol x86_32-abi)
        (backend-id 0)
        (state 4)
        (backend /local/domain/0/backend/vif/7/0)
        (tx-ring-ref 509)
        (rx-ring-ref 508)
        (feature-rx-notify 1)
        (event-channel 7)
    )
)

Thanks in advance for any help.

>How-To-Repeat:
Try to netinstall a NetBSD 5.1 DomU on Debian Squeeze (linux 2.6.32-5 with 
pvops, Xen 4).
>Fix: