Red Hat Summit10.11. Hot plugging secondary network interfaces
You can add or remove secondary network interfaces without stopping your virtual machine (VM). OpenShift Virtualization supports hot plugging and hot unplugging for secondary interfaces that use bridge binding and the VirtIO device driver. OpenShift Virtualization also supports hot plugging secondary interfaces that use SR-IOV binding. To hot plug or hot unplug a secondary interface, you must have permission to create and list VirtualMachineInstanceMigration objects.
Hot unplugging is not supported for Single Root I/O Virtualization (SR-IOV) interfaces.
10.11.1. VirtIO limitations
Each VirtIO interface uses one of the limited Peripheral Connect Interface (PCI) slots in the VM. There are a total of 32 slots available. The PCI slots are also used by other devices and must be reserved in advance, therefore slots might not be available on-demand.
OpenShift Virtualization reserves up to four slots for hot plugging interfaces. This includes any existing plugged network interfaces. For example, if your VM has two existing plugged interfaces, you can hot plug two more network interfaces.
The actual number of slots available for hot plugging also depends on the machine type. For example, the default PCI topology for the q35 machine type supports hot plugging one additional PCIe device. For more information on PCI topology and hot plug support, see the libvirt documentation.
If you restart the VM after hot plugging an interface, that interface becomes part of the standard network interfaces.
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