Commit Graph

6 Commits

Author SHA1 Message Date
Eric Farman 3d6519968b pc-bios: s390x: Clear out leftover S390EP string
A Linux binary will have the string "S390EP" at address 0x10008,
which is important in getting the guest up off the ground. In the
case of a reboot (specifically chreipl going to a new device),
we should defer to the PSW at address zero for the new config,
which will re-write "S390EP" from the new image.

Let's clear it out at this point so that a reipl to, say, a DASD
passthrough device drives the IPL path from scratch without disrupting
disrupting the order of operations for other boots.

Rather than hardcoding the address of this magic (again), let's
define it somewhere so that the two users are visibly related.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20201120160117.59366-3-farman@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-11-23 09:48:45 +01:00
Janosch Frank fe75c657b8 pc-bios: s390x: Use PSW masks where possible and introduce PSW_MASK_SHORT_ADDR
Let's move some of the PSW mask defines into s390-arch.h and use them
in jump2ipl.c. Also let's introduce a new constant for the address
mask of 8 byte (short) PSWs.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200624075226.92728-8-frankja@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-07-02 10:00:32 +02:00
Janosch Frank b88faa1c89 pc-bios: s390x: Rename PSW_MASK_ZMODE to PSW_MASK_64
This constant enables 64 bit addressing, not the ESAME architecture,
so it shouldn't be named ZMODE.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200624075226.92728-7-frankja@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-07-02 10:00:11 +02:00
Janosch Frank 9bfc04f9ef pc-bios: s390x: Save iplb location in lowcore
The POP states that for a list directed IPL the IPLB is stored into
memory by the machine loader and its address is stored at offset 0x14
of the lowcore.

ZIPL currently uses the address in offset 0x14 to access the IPLB and
acquire flags about secure boot. If the IPLB address points into
memory which has an unsupported mix of flags set, ZIPL will panic
instead of booting the OS.

As the lowcore can have quite a high entropy for a guest that did drop
out of protected mode (i.e. rebooted) we encountered the ZIPL panic
quite often.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Message-Id: <20200304114231.23493-19-frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-03-10 10:18:08 +01:00
Jason J. Herne efa47d36da s390-bios: Support booting from real dasd device
Allows guest to boot from a vfio configured real dasd device.

Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <1554388475-18329-16-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-04-12 12:40:35 +02:00
Jason J. Herne c95df3d108 s390-bios: Map low core memory
Create a new header for basic architecture specific definitions and add a
mapping of low core memory. This mapping will be used by the real dasd boot
process.

Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1554388475-18329-7-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-04-12 12:40:35 +02:00