VT-d not working for FreeBSD 9.0 guest

[Shesha Sreenivasamurthy <sheshas@gmail.com>]

I'm using FreeBSD 9.0 (FreeBSD freebsd9-i386 9.0-RELEASE FreeBSD 9.0-RELEASE)
as my guest OS with qemu-kvm (qemu-kvm-1.1-rc2/x86_64-softmmu/
qemu-system-x86_64) running on centos 6.2 (CentOS release 6.2) with
2.6.32-220.el6.x86_64 kernel. I am using Intel's 82599EB 10-Gigabit hardware
on the host, which I am trying to export into the FreeBSD guest OS. The guest
driver (version 2.4.4) will claim it.  However, the status is shown as
"no carrier" an therefore cannot ping any other system.

$ ifconfig ix0
ix0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        
options=401bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,
VLAN_HWCSUM,TSO4,VLAN_HWTSO>
        ether 90:e2:ba:0d:3d:b0
        inet 4.4.4.1 netmask 0xffffff00 broadcast 4.4.4.255
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
        media: Ethernet autoselect
        status: no carrier

On the host side, before the ixgbe is loaded in the guest, /proc/interrupts
show the following entry for kvm

# cat /proc/interrupts | grep kvm
  30:          0          0          0          0          0          0
  0          0          0          0          0          0          0
  0          0          0 IR-IO-APIC-fasteoi kvm_assigned_intx_device

However, after the driver is loaded, the above entry is gone but two new
entries show up.

# cat /proc/interrupts | grep kvm
  76:          0          0          0          0          0          0
  0          0          0          0          0          0          0
  0          0          0          IR-PCI-MSI-edge   kvm_assigned_msix_device
  77:          0          0          0          0          0          0
  0          0          0          0          0          0          0
  0          0          0          IR-PCI-MSI-edge  kvm_assigned_msix_device.

To make sure, the my host configurations are fine, I loaded linux guest, with
exact same qemu params and host configurations. It works just fine.

What I noticed in case linux guest is, to start with same entry is seen in
/proc/interrupts. However, after the ixgbe is loaded in the guest, I see only
one entry instead of two as in case of freebsd.

# cat /proc/interrupts | grep kvm
  30:          0          0          0          0          0          0
  0          0          0          0          0          0          0
  0          0          0       IR-IO-APIC-fasteoi   kvm_assigned_intx_device

# cat /proc/interrupts | grep kvm
  76:          0          0          0          0          0          0
  0          0          0          0          0          0          0
  0          0          0          IR-PCI-MSI-edg   kvm_assigned_msi_device

Similar problem was reported earlier too: 
http://comments.gmane.org/gmane.comp.emulators.kvm.devel/83806

Any ideas or advice will be highly valued

Thanks,
Shésha.