zdump: Add vmdump dfi for vmdump format to elf format

Add support for vmdump 64big format to the zgetdump utility.
The result is an elf file suitable for tool crash.
This patch adds file dfi_vmdump.c to handle conversion from
z/VM vmdump format to the internal memory representation of this tool.
Therefore both output formats elf and s390 are supported as target
of the conversion.

The vmdump file formats 32bit and 64bit are not supported anymore.
They have been obsolete since CP version 5.1 (end of service since
30-Sep-2009).

Vector register set is not part of a vmdump file and can not be
displayed.

Output before:
 # zgetdump ~/vmdump-0383
 zgetdump: No valid dump found on "/root/vmdump-0383"
 #

Output after:
 # ./zgetdump ~/vmdump-0383 ~/vmdump-0383.elf
 Format Info:
  Source: vmdump
  Target: elf

 Copying dump:
  00000000 / 00000379 MB
  00000379 / 00000379 MB

 Success: Dump has been copied
 # file ~/vmdump-0383.elf
 /root/vmdump-0383.elf: ELF 64-bit MSB core file, IBM S/390, version 1 \
	 .... (SYSV), SVR4-style, from 'vmlinux'
 #

 # ./zgetdump -i ~/vmdump-0383
 General dump info:
  Dump format........: vmdump
  Version............: 2
  UTS node name......: s8360046.lnxne.boe
  UTS kernel release.: 6.1.0-rc2-d-perf+
  UTS kernel version.: #1 SMP Fri Oct 28 09:42:13 CEST 2022
  System arch........: s390x (64 bit)
  CPU count (online).: 2
  CPU count (real)...: 2
  Dump memory range..: 2048 MB

 Memory map:
  0000000000000000 - 000000007fffffff (2048 MB)
 #

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

zdump/zgetdump.8

@@ -1,10 +1,10 @@
-.\" Copyright 2022 IBM Corp.
+.\" Copyright 2023 IBM Corp.
 .\" s390-tools is free software; you can redistribute it and/or modify
 .\" it under the terms of the MIT license. See LICENSE for details.
 .\"
-.TH ZGETDUMP 8 "October 2022" "s390-tools"
+.TH ZGETDUMP 8 "January 2023" "s390-tools"
 .SH NAME
-zgetdump \- Tool for copying and converting System z dumps
+zgetdump \- Tool for copying and converting IBM zSystems dumps
 .SH SYNOPSIS
 
 \fBzgetdump\fR    DUMP [-s SYS] [-f FMT] [-k KEY] > DUMP_FILE
@@ -107,6 +107,8 @@ source dump is located:
 .IP "         -" 12
 Regular dump file (e.g. /dumps/dump.0)
 .IP "         -" 12
+vmdump file (e. g. VMDUMP.FILE)
+.IP "         -" 12
 DASD partition device node (e.g. /dev/dasdc1)
 .IP "         -" 12
 DASD device node for multi-volume dump (e.g. /dev/dasdc)
@@ -186,16 +188,22 @@ Linux user space core dumps.
 Protected virtualization vmcore dump in Executable and Linkable Format
 .TP
 .BR "s390"
-This dump format is System z specific and is used for DASD and tape dumps.
+This dump format is IBM zSystems specific and is used for DASD and tape dumps.
 .TP
 The following dump formats are supported for the source dump only:
 .TP
 .BR "s390_ext"
-This dump format is System z specific and is used for DASD dumps only.
+This dump format is IBM zSystems specific and is used for DASD dumps only.
+.TP
+.BR "vmdump"
+Dumps with this format are created by the z/VM vmdump command
+and stored in the reader device.
+Use the "vmur" tool to extract such dumps from the reader
+device and save them on disk.
 .TP
 .BR "lkcd"
 This dump format is used by the Linux Kernel Crash Dumps (LKCD) project
-and also on System z for the "vmconvert" dump tool.
+and also on IBM zSystems for the "vmconvert" dump tool.
 .TP
 .BR "devmem"
 On live systems the /dev/mem or /dev/crash device nodes can be used as source