Re: [libvirt] [PATCH 0/4] Support mac and port profile for <interface type='hostdev'>

On 03/01/2012 04:02 AM, Roopa Prabhu wrote: I'm unable to test that part, as I don't have any 802.1QbX capable switches (and it sounds like the design is problematic anyway.) Success!! I tried this for VFs that have a netdev driver attached, and VFs that don't, and it behaved properly in both cases - when the guest is started, the MAC address is set properly for the guest to use, and when the guest is stopped, the MAC address of that VF is restored to its original value (implying that your code to save the old MAC address works properly). This one has a problem, at least with my non-sriov hardware (which happens to be the onboard NetXtreme device of a Thinkstation, using the tg3 driver) it appears the MAC address gets reset to its original setting at some point after libvirt changes it. To help understand what happens - assume the device's original MAC address is o:o:o:o:o:o, and my xml looks like this: <interface type='hostdev' managed='yes'> <mac address='n:n:n:n:n:n'/> ... </interface> When the guest boots up, ifconfig shows there is an interface with mac address o:o:o:o:o:o. Additionally, if I manually change the mac address to p:p:p:p:p:p on the host before starting the guest, when the guest boots, ifconfig shows the mac address as... o:o:o:o:o:o. So, whether or not libvirt is successfully setting the mac address, it's getting reset (probably by the card's firmware). So perhaps this is another case of wanting to do something that just isn't possible, and the way out is to simply generate an error on domain startup if the netdev being passed through isn't a VF?