I've put everything I've found in the comments starting at
https://bugs.launchpad.net/qemu/+bug/1920913/comments/8 but basically it looks to me like the start of one of the instructions (ebde f000 ec51; tmy -81920(%r15),222) is getting overwritten from 0xebde to 0x0000 somehow.
Any suggestions on where to look or what other info I could provide would be greatly appreciated.
Thanks,
Jonathan Albrecht
Linux on IBM Z Open Source Ecosystem
IBM Canada Toronto Lab