Building a kernel with the cryptographic device driver

7.1 LPAR mode z/VM guest KVM guest

Control the build options for the cryptographic device driver 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.

Select the option CONFIG_ZCRYPT to include the cryptographic device driver.

Support for customized device nodes is always enabled, for details see Creating customized device nodes.

Figure 1. zcrypt kernel configuration menu options

 Cryptographic API --->
    ...
    Hardware crypto devices  --->
       Support for s390 cryptographic adapters       (CONFIG_ZCRYPT)

You can compile the entire support for s390 cryptographic adapters into the kernel or you can specify 'm' for separate modules. Regardless of this choice, the base AP bus support is compiled into the kernel.

Specifying 'm' results in the following separate modules for specific adapter or function support:

zcrypt: request dispatcher, secure key messages, and clear key messages module. Loads the rng_core module.
zcrypt_cex4: device driver for all CEX4S, CEX5S, CEX6S, CEX7S, and CEX8S adapters.