9.4. System Devices
System devices are critical for the guest to run and cannot be removed. Each system device attached to a guest also takes up an available PCI slot. The default system devices are:
- Host bridge
- ISA bridge and USB bridge (The USB and ISA bridges are the same device)
- Graphics card using the VGA or qxl driver
- Memory balloon device
For information about how to use PCI Express and conventional PCI devices with Intel Q35-based virtual machines, see Using PCI Express and Conventional PCI Devices with the Q35 Virtual Machine.