The key word is PCI passthrough. Using this method, one can bind PCI devices directly to the VM, and the host cannot see the devices at all.
This is an example of PCI passthrough definition in
<hostdev mode="subsystem" type="pci" managed="yes">
<address domain="0x0000" bus="0x08" slot="0x00" function="0x0"/>
<address type="pci" domain="0x0000" bus="0x05" slot="0x00" function="0x0"/>
To add a device to the VM in
virt-manager, take the followint steps:
1. Make sure the VM is shut down.
2. Open the VM details tab, and click "Add Hardware" on the left bottom.
3. Select `PCI Host Device`.
4. Select your device from the list.
After this, the device is disconnected from the host when VM starts and it is attached to the VM.