Online and configuration state

In contrast, changing the online state of a PCI function in KVM or z/VM® guests has no effect on the function's configuration state in the partition. KVM or z/VM guests depend on the hypervisor to control the configuration state. For more information about controlling the configuration state of PCI functions from z/VM, see the z/VM documentation.

PCI functions cannot be used concurrently by operating systems in multiple partitions. If the hardware configuration makes a PCI function eligible for multiple partitions, the function becomes exclusively assigned to the first partition that configures it. This assignment persists, across POR cycles of the partition, until the PCI function is explicitly deconfigured. Setting a PCI function offline from Linux in LPAR mode also deconfigures it in the partition and so makes it available to other eligible partitions.

During the installation of a new Linux instance, the installer requires a network connection. If RoCE Express is the only available network adapter, one of its PCI functions must be configured before the installation begins, see Using a PCI function during a Linux installation.