Greetings Michal, I think I might be doing something wrong, all the devices are defined a such: <interface type='network'> <mac address='52:54:xx:xx:xx:xx'/> <source network='mynet'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x10' slot='0x0x' function='0x0'/> </interface> and I still cannot get vfio to attached to them. they are autobinded to virtio_pci so I had to unbind them first when I reload the vfio module, I get the same errors below I'm trying to attach it inside a running guest, in short, I want to be able to pass a vNIC to a nested guest for development reasons Thanks, Dagg > Sent: Thursday, June 13, 2024 at 5:45 PM > From: "Michal Prívozník" <mprivozn(a)redhat.com&gt; > To: "daggs" <daggs(a)gmx.com&gt;, users(a)lists.libvirt.org > Subject: Re: vfio usage in a vm > > On 6/12/24 20:24, daggs via Users wrote: > > Greetings, > > > > I wanted to know if it is possible to attach a virtual nic (shows up as 02:01.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev 20)) to the vfio module, when I modprobe it I get this error: > > [ 854.624668] vfio-pci: probe of 0000:02:01.0 failed with error -22 > > > No, you need to declare the vNIC with model 'virtio': > > <interface type='network'> > <mac address='52:54:00:XX:XX:XX'/> > <source network='default'/> > <model type='virtio'/> > </interface> > > Virtio is an interface that allows more effective data transfer between > host and guest [1][2]. It's a paravirtualized device. In other words, if > you started a guest and told hypervisor to emulate RTL8139 NIC then > it'll do just that. > > 1: https://wiki.osdev.org/Virtio > 2: https://wiki.libvirt.org/Virtio.html > > Michal > >

thanks, after enabling the iommu in the guest, vfio-pci is attached to the nics. thanks for all the help Dagg