tree 48247426a662b82c2bd8a4b28054f3b715f60e6d
parent 3585cb0280654acbc559a360a839c8d58bb0cb87
author Michael Holzheu <holzheu@linux.vnet.ibm.com> 1412611063 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1412838856 +0200

s390/kdump: add support for vector extension

With this patch for kdump the s390 vector registers are stored into the
prepared save areas in the old kernel and into the REGSET_VX_LOW and
REGSET_VX_HIGH ELF notes for /proc/vmcore in the new kernel.

The NT_S390_VXRS_LOW note contains the lower halves of the first 16 vector
registers 0-15. The higher halves are stored in the floating point register
ELF note.  The NT_S390_VXRS_HIGH contains the full vector registers 16-31.

The kernel provides a save area for storing vector register in case of
machine checks. A pointer to this save are is stored in the CPU lowcore
at offset 0x11b0. This save area is also used to save the registers for
kdump. In case of a dumped crashed kdump those areas are used to extract
the registers of the production system.

The vector registers for remote CPUs are stored using the "store additional
status at address" SIGP. For the dump CPU the vector registers are stored
with the VSTM instruction.

With this patch also zfcpdump stores the vector registers.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>