Using a PCI function during a Linux installation

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An operational network device is a prerequisite for installing Linux® on IBM Z® or LinuxONE systems. You can use a PCI network adapter PCI function to provide this device.

Assuring that the PCI function is available

For installing Linux as a KVM or z/VM® guest, you must assure that the hypervisor makes the PCI function available to the virtual server or guest virtual machine. No further action is needed.

For installations in an LPAR or DPM partition, the PCI functions must be configured for the partition, which depends on several conditions.
  • The hardware system defaults or settings might configure the PCI function for the partition. For example, if the PCI function is listed in an LPAR access list, it is automatically configured when the LPAR is started.
  • For DPM partitions, you can specify the PCI function for auto-configuration when an operating system is started. For more information, see the section about device auto-configuration in Device Drivers, Features, and Commands.
  • If the PCI function was online in the operating system that previously ran in the partition, it remains configured for the partition.

If the PCI function is not configured for the partition, use hardware management interfaces to configure it, see Using the SE or HMC to configure a PCI function for a partition.

Specifying the network interface name for the installer

Depending on your distribution, you can specify the network interface during the installation. Your distribution might display the available network interfaces on the Operating System Messages applet of the SE or HMC and prompt you to select one. For installations of KVM or z/VM guests, you might be prompted in the KVM host or z/VM CP session that drives the installation.

For other distributions, you must specify suitable kernel parameters for the installer. For example, for a Red Hat® Enterprise Linux installation, you can specify the interface name with the ip= or vlan= kernel parameter. If the network conventions and regulations at your installation permit it, you can use DHCP to get an automatic IP configuration.

Network interface names for network adapter PCI functions depend on your environment, see Network interface names. If your Linux instance uses predictable interface names, specify the expected name. For example, specify eno8 if UID uniqueness is enforced and the UID of your PCI function is 0x8.

Tip: If you are not sure about the network interface name, specify your best guess and observe the kernel messages that are displayed on the SE or HMC during the installation. Watch out for a message like this and, if necessary, repeat the installation with the correct name.
...
[...] mlx5_core 0008:00:00.0: enP8p0s0: renamed from eth0
...
Hint: If there is no such line, confirm that the PCI function is available to the installer. Assure that the PCI function configured for your partition or that the KVM or z/VM hypervisor makes it available to the virtual server or guest virtual machine.

Installer specification example for Red Hat Enterprise Linux 8

In a .prm file, add a line like this to specify eno8 as the interface name:
ip=10.10.92.31::10.10.92.30:16:<lpar>:eno8:none