Martin Husemann wrote:
On Thu, Jun 21, 2012 at 11:24:37AM +0100, Roger Pau Monne wrote:Then we end up with the same problem, since xl needs to know the name of the created device (to launch the appropriate hotplug scripts), and there's not way to fetch that from Qemu.I thought I saw command line options to invoke qemu that pass the tap ifname, or even open a fd and just pass the number? Something like: qemu -net tap,ifname=tap14 or qemu -net tap,fd=4 and you could pass the name to the script vie environment vars.
As I said on a previous email, how can you guarantee that the name you chose and pass to Qemu will not be taken by someone else while you are calling Qemu?
You might even be launching several guests at the same time, which will lead you to a race.