Getting Started: RHEL 7.5 Instructions added

Instructions for RHEL7.5 were added to the Getting Started with KVM on Z series.
See here for the actual page.

RHEL 7.5 with support for KVM on Z available

Red Hat Enterprise Linux 7.5 is out. From the release notes, available here:

Availability across multiple architectures
To further support customer choice in computing architecture, Red Hat Enterprise Linux 7.5 is simultaneously available across all supported architectures, including x86, IBM Power, IBM z Systems, and 64-bit Arm.

Support for IBM Z is available through the kernel-alt package, as indicated earlier here, which provides Linux kernel 4.14. QEMU ships v2.10 via package qemu-kvm-ma, and libvirt is updated to v3.9.0 for all platforms.
Thereby, all IBM z14 features as previously listed here are available.
Check these instructions on how to get started. 

RHEL 7.5 Beta supports KVM on Z

The Red Hat Enterprise Linux 7.5 Beta ships with support for KVM on Z through the kernel-alt packages. This will essentially ship Linux kernel 4.14.
Here is the respective section from the release notes:

KVM virtualization is now supported on IBM z Systems. However, this feature is only available in the newly introduced user space based on kernel version 4.14, provided by the kernel-alt packages.

See here for further details.