The z/VM® IUCV HVC device driver is a kernel module that uses device nodes to enable HVC terminal devices to communicate with getty and login programs.
There can be up to 8 HVC terminal devices, hvc0 to hvc7. hvc0 can be activated to receive Linux kernel messages. The terminal IDs for HVC terminal devices match the device names with a leading "lnx". For example, the terminal ID for hvc0 is lnxhvc0.
Connection requests are created with the iucvconn program on the terminal server. A request includes the z/VM user ID of the target z/VM guest virtual machine and the terminal ID of an HVC terminal device.
The z/VM IUCV
HVC device driver maps the terminal ID to the
corresponding terminal device. As of kernel 3.14,
lnxhvc can be used as a generic terminal ID that maps to any free HVC terminal
device.
A systemd instance unit, an inittab entry, or an Upstart job file associates the HVC
terminal device with a login program.