
Issue 11
© Solarflare Communications 2014
322
Solarflare Server Adapter
User Guide
7.7 Migration
Libvirt has been extended to fully support migrating a guest VM using SR-IOV acceleration between
two KVM hosts.
Consider migrating a VM from host A to host B (
). Before migration libvirt will remove all
VFs from the VM. Once the VM reaches host B VFs will be allocated, initialized and attached as
previously described. If there are no VFs free then the VM will no longer be accelerated. If the
migration fails for whatever reason then the VM will remain on host A, and the VFs will be
reattached to the VM.
Figure 53: Migrating a guest - KVM
Limitations
• Virt-manager will support bridges on top of vlan interfaces but the vlan interface should be
named as ethx.<vlan_id>.
• RHEL 6.1 driver - Libvirt will not configure VFs manually added to a VM configuration (via virt-
manager or virsh edit). Only VFs attached via the vf-hotplug XML element will be configured.
• RHEL 6.2 driver - Libvirt will not configure VFs manually added to a VM configuration (via virt-
manager or virsh edit). Only VFs attached via the
pci_passthrough-hybrid forward mode
and pf dev
XML element will be configured.