Comment 3 for bug 1798084

I can confirm that the message:
"Could not read keymap file: 'en-us'"
does not occur in case the "qemu-system-data" package is installed.

$ sudo qemu-system-s390x -enable-kvm
Could not read keymap file: 'en-us'
$ sudo apt install qemu-system-data
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  qemu-system-data
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 706 kB of archives.
After this operation, 2,731 kB of additional disk space will be used.
Get:1 http://us.ports.ubuntu.com/ubuntu-ports cosmic/main s390x qemu-system-data all 1:2.12+dfsg-3ubuntu7 [706 kB]
Fetched 706 kB in 0s (20.4 MB/s)
Selecting previously unselected package qemu-system-data.
(Reading database ... 54122 files and directories currently installed.)
Preparing to unpack .../qemu-system-data_1%3a2.12+dfsg-3ubuntu7_all.deb ...
Unpacking qemu-system-data (1:2.12+dfsg-3ubuntu7) ...
Setting up qemu-system-data (1:2.12+dfsg-3ubuntu7) ...
Processing triggers for man-db (2.8.4-2) ...
$ sudo qemu-system-s390x -enable-kvm
VNC server running on ::1:5900