Comment 1 for bug 953754

And if you try with smp=4, you may see some error info from qemu.
"assigned_dev_update_msix_mmio: No such device or address
fail to set MSI-X entry number for MSIX! Invalid argument"
The message is generated from the funtion "assigned_dev_update_msix_mmio" in
hw/device-assignment.c
1035 r = kvm_assign_set_msix_entry(kvm_state, &msix_entry);
1036 if (r) {
1037 fprintf(stderr, "fail to set MSI-X entry! %s\n",
strerror(-r));
1038 break;
1039 }

Some logs:
[root@vt-nhm9 jay]# qemu-system-x86_64 -m 512 -smp 4 -device
pci-assign,host=11:00.0,id=nic1 -net none -device
pci-assign,host=11:00.1,id=nic2 -net none -hda rhel6u1.qcow
Could not open option rom 'kvmvapic.bin': No such file or directory
Could not open option rom 'vapic.bin': No such file or directory
VNC server running on `::1:5900'
assigned_dev_update_msix_mmio: No such device or address
fail to set MSI-X entry number for MSIX! Invalid argument
assigned_dev_update_msix_mmio: Invalid argument
fail to set MSI-X entry number for MSIX! Invalid argument
assigned_dev_update_msix_mmio: Invalid argument
fail to set MSI-X entry number for MSIX! Invalid argument
assigned_dev_update_msix_mmio: Invalid argument
fail to set MSI-X entry number for MSIX! Invalid argument
assigned_dev_update_msix_mmio: Invalid argument