There are some characteristics of HVC terminal devices you should know.
Output that is written by Linux while the terminal session for an HVC terminal device is closed is not displayed. Therefore, a newly opened terminal window is always blank. For most applications, like login or shell prompts, it is sufficient to press Enter to obtain a new prompt.
You can also call magic sysrequest functions from the hvc0 terminal device if it is present and activated to receive Linux kernel messages. To call the magic sysrequest functions from hvc0, enter the single character Ctrl+o followed by the character for the particular function. See Documentation/sysrq.txt in the Linux source tree for the available magic sysrequest functions.
Your distribution might not have enabled all of the listed functions. For information about enabling magic sysrequest functions see Device Drivers, Features, and Commands, SC33-8411 and the hvc_iucv man page.
Always end sessions with HVC terminal devices by explicitly logging off (for example, type exit and press Enter). If a logoff results in a new login prompt, press Control and Underscore (Ctrl+_) then press d to close the terminal session. Simply closing the terminal window for a hvc0 terminal device that was activated for Linux kernel messages leaves the device active. The terminal session can then be reopened without a login.