[libvirt] Trouble starting a QEMU guest with IPv6 VNC address

[Kaitlin Rupert]

Hello,

I am trying to start a QEMU guest with an IPv6 VNC address.  I can 
specify the address and start the guest, but the VNC port shows up under 
the IPv4 list:

# virsh dumpxml domU1 | grep graphics
     <graphics type='vnc' port='5900' autoport='no' listen='::1' 
keymap='en-us'/>

# cat /proc/net/tcp | grep 170C
    2: 00000000:170C 00000000:0000 0A 00000000:00000000 00:00000000 
00000000     0        0 621103 1 ffff88007a043a80 299 0 0 2 -1 


# cat /proc/net/tcp6 | grep 170C
#

# ps -ef | grep qemu
root     16451     1 43 04:17 ?        00:00:18 
/usr/bin/qemu-system-x86_64 -S -M pc -m 128 -smp 1 -name domU1 -uuid 
2aebe290-d1ed-11dd-90eb-001a64bc024c -monitor pty -pidfile 
/var/run/libvirt/qemu//domU1.pid -no-acpi -boot c -drive 
file=/tmp/default-kvm-dimage,if=ide,index=0,boot=on -net 
nic,macaddr=11:22:33:aa:bb:cc,vlan=0 -net tap,fd=17,vlan=0 -serial none 
-parallel none -usb -vnc ::1:0 -k en-us

I started the same guest manually, but I appended an ",ipv6' flag to the 
vnc option (see below).  With this change, the port shows up in the IPv6 
list.

# /usr/bin/qemu-system-x86_64 -M pc -m 128 -smp 1 -name domU1 -uuid 
2aebe290-d1ed-11dd-90eb-001a64bc024c -monitor pty -pidfile 
/var/run/libvirt/qemu//domU1.pid -no-acpi -boot c -drive 
file=/tmp/default-kvm-dimage,if=ide,index=0,boot=on -net 
nic,macaddr=11:22:33:aa:bb:cc,vlan=0 -net tap,fd=17,vlan=0 -serial none 
-parallel none -usb -vnc ::1:0,ipv6 -k en-us

# cat /proc/net/tcp6 | grep 170C
    2: 00000000000000000000000000000000:170C 
00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 
00000000     0        0 621485 1 ffff88007a30ad00 299 0 0 2 -1

# cat /proc/net/tcp | grep 170C
#

I'd like to fix the qemu driver so that it specifies this flag, but I am 
unsure whether a guest XML change or some other change is appropriate 
here.  Would it be better to have the qemu driver code do some detection 
on the address that is passed in?

Thanks!
-- 
Kaitlin Rupert
IBM Linux Technology Center
kaitlin at linux.vnet.ibm.com