Building a kernel with the PCIe support

6.18 LPAR mode z/VM guest KVM guest

Control the build options for the PCIe support through the kernel configuration menu.

Kernel builders: This information is intended for those who want to build their own kernel. Be aware that both compiling your own kernel or recompiling an existing distribution usually means that you have to maintain your kernel yourself.

Figure 1 summarizes the kernel configuration menu options that are relevant to the PCIe support:

Figure 1. PCIe kernel configuration menu options


I/O subsystem --->
   ...       
   PCI support --->                                      (CONFIG_PCI)
      Maximum number of PCI functions (1-4096)           (CONFIG_PCI_NR_FUNCTIONS)
         ...
         Support for PCI Hotplug ---> (common code option CONFIG_HOTPLUG_PCI)
            ...
            System z PCI Hotplug Support                 (CONFIG_HOTPLUG_PCI_S390)

CONFIG_PCI: Enable PCI support.
Hint: Configuration-option defaults and inter-dependencies likely result in the CONFIG_USB_SUPPORT being selected automatically when selecting CONFIG_PCI. To avoid unwanted support for USB and related items, ensure that CONFIG_USB_SUPPORT is disabled at Device drivers > USB Support in the configuration menu.
CONFIG_PCI_NR_FUNCTIONS: This option specifies the maximum number of PCI devices that this kernel supports.
CONFIG_HOTPLUG_PCI_S390: Hotplug support enables simple online and offline configuration through the power sysfs attribute.

If selected, the PCIe support is compiled into the kernel.