[IBM Z / S390X] VM machine type supported on RHEL 8 and Leapp 7>8

Issue

• Running Leapp to In-place Upgrade from RHEL 7 to RHEL 8 fails with "Unable to install RHEL 8 userspace packages", and then a set of RPM postinst scriptlets errors is seen:

  leapp.workflow.TargetTransactionFactsCollection.target_userspace_creator: Error in POSTIN scriptlet in rpm package libsepol
  

• The glibc crashes on "VX" (extended vectors) instructions:

  [1132137.589284] Last Breaking-Event-Address:
  [1132137.589285] [<000003fffd150dc4>] 0x3fffd150dc4
  [1132306.305861] User process fault: interruption code 0x60001 in ld-2.28.so[3fffd2d0000+29000] <<<<<
  [1132306.305875] CPU: 3 PID: 32940 Comm: bash Kdump: loaded Tainted: G ------------ T 3.10.0-1160.95.1.el7.s390x #1
  [1132306.305878] task: 00000000025e2340 ti: 00000000e2804000 task.ti: 00000000e2804000
  [1132306.305881] User PSW : 0705200180000000 000003fffd2e7e04 (0x3fffd2e7e04)
  [1132306.305894] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:2 PM:0 EA:3
  User GPRS: 000003ff00000002 0000000000000021 000003ffff851aa0 000003ffff851b90
  [1132306.305899] 000003fffd2fad70 000003fffd2d03b0 000003fffd2fafa0 000003fffd2d1048
  [1132306.305902] 000003fffd2d0000 000003fffd2d1048 000003fffd2e9e88 000003fffd2d0570
  [1132306.305905] 000003fffd2faf70 000003fffd2f0ae0 000003ffff851928 000003ffff851868
  [1132306.305917] User Code: 000003fffd2e7df4: a7840118 brc 8,3fffd2e8024
  000003fffd2e7df8: c040000097bc larl %r4,3fffd2fad70
  #000003fffd2e7dfe: e70040000802 vleg %v16,0(%r4),0
  >000003fffd2e7e04: c040000097be larl %r4,3fffd2fad80
  000003fffd2e7e0a: 68304000 ld %f3,0(%r4)
  000003fffd2e7e0e: c04000009671 larl %r4,3fffd2faaf0
  000003fffd2e7e14: e72040000802 vleg %v18,0(%r4),0
  000003fffd2e7e1a: c04000009673 larl %r4,3fffd2fab00
  [1132306.305957] Last Breaking-Event-Address:
  [1132306.305959] [<000003fffd2e7dc4>] 0x3fffd2e7dc4