________________________________ From: Peter Krempa <[email protected]> Sent: Tuesday, March 30, 2021 01:42 PM To: Waleed Musa <[email protected]> Cc: [email protected] <[email protected]>; Moshe Levi <[email protected]>; Adrian Chiris <[email protected]> Subject: Re: [Libvirt] Attach qemu commands to an running xml domain
External email: Use caution opening links or attachments On Tue, Mar 30, 2021 at 09:35:48 +0000, Waleed Musa wrote: > Hi all, > > I see in libvirt you are supporting attach/detach devices to existing xml > domain using attachDeviceFlags and detachDeviceFlags APIs. > Now we are adding some qemu command to the xml domain related to some > interfaces using alias names before starting the VM, but we will face an > issue with hot plug such devices, so I have two question here: > > 1. Is it applicable to set the alias names for interfaces because I saw > it's ignored when I add it to xml domain before starting the VM? User specified aliases are possible with 'ua-' prefix: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.libvirt.org%2Fformatdomain.html%23devices&data=04%7C01%7Cwaleedm%40nvidia.com%7C72e7134a4ea6450695c108d8f368917a%7C43083d15727340c1b7db39efd9ccc17a%7C0%7C1%7C637526977746721327%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=xPxNJBFbsO4BFB3zkTGR4W9AruwHttjKOxYVyxF9XpI%3D&reserved=0 > Thanks, I'll try it > 2. Is there a way or API to attach qemu commands to running domain as you > are doing in attaching the device using attachDeviceFlags? No. For VMs which use <qemu:commandline> we don't formally provide support. I suggest that if you have a good use case for the attributes below, you send patches adding the functionality to libvirt if you want to have it on device hotplug. > We can't implement hot-plug > > Example of my xml > <domain type='kvm' id='5' > xmlns:qemu='https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Flibvirt.org%2Fschemas%2Fdomain%2Fqemu%2F1.0&data=04%7C01%7Cwaleedm%40nvidia.com%7C72e7134a4ea6450695c108d8f368917a%7C43083d15727340c1b7db39efd9ccc17a%7C0%7C1%7C637526977746721327%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=AK2tXXVGhKiJgFOZyKwiVOcOKCU49jSscbwQduaXSww%3D&reserved=0'> > <devices> > <interface type='vhostuser'> > <mac address='fa:16:3e:ac:12:4c'/> > <source type='unix' path='/var/lib/vhost_sockets/sockbbb6bbe9-eb5' > mode='server'/> > <target dev='tapbbb6bbe9-eb'/> > <model type='virtio'/> > <driver queues='4' rx_queue_size='512' tx_queue_size='512'/> > <alias name='net0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x03' > function='0x0'/> > </interface> > </devices> > <qemu:commandline> > <qemu:arg value='-set'/> > <qemu:arg value='device.net0.page-per-vq=on'/> > <qemu:arg value='-set'/> > <qemu:arg value='device.net0.host_mtu=8942'/> > </qemu:commandline> > </domain> > > > Regards, > Waleed Mousa > Software Engineer, > Nvidia <https://www.nvidia.com/en-me/geforce/> >
