Harald Freudenberger 0fef40be5d s390/ap: fix crash on older machines based on QCI info missing ... On older z series machines (z12 and older) there is no QCI info available. The AP code took care of this and the AP bus scan then switched to simple probing via TAPQ. With commit 283915850a ("s390/ap: notify drivers on config changed and scan complete callbacks") some code was introduced which silently assumed that the QCI info is always available. However, with KVM simulating an older machine (z12) the result was a kernel crash. Funnily the same crash does not happen on LPAR - maybe because NULL is a valid pointer and reading some data from address 0 also works fine. This fix now improves the code to be aware that the QCI instruction may not be available on older machines and thus the two pointers to QCI info structs may simple be NULL. However, on a machine not providing the QCI info the two callbacks to the zcrypt device drivers on_config_changed() and on_scan_complete() provide parameters which are pointers to a QCI info struct. These both callbacks are NOT served if there is no QCI info available. The only consumer of these callbacks is the vfio device driver. This driver only supports CEX4 and higher. All physical machines which are able to provide CEX4 cards have QCI support available. So there is no sense in for example fill the QCI info struct by hand with looping over cards and queues and TAPQ each APQN. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> Cc: stable@vger.kernel.org Fixes: 283915850a ("s390/ap: notify drivers on config changed and scan complete callbacks") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>		2022-08-15 17:19:52 +02:00
..
block	s390/dasd: Establish DMA alignment	2022-08-04 16:19:15 -06:00
char	s390 updates for 5.20 merge window	2022-08-06 17:05:21 -07:00
cio	VFIO updates for v6.0-rc1	2022-08-06 08:59:35 -07:00
crypto	s390/ap: fix crash on older machines based on QCI info missing	2022-08-15 17:19:52 +02:00
net	s390/qeth: cache link_info for ethtool	2022-08-08 20:57:56 -07:00
scsi	scsi: zfcp: Fix missing auto port scan and thus missing target ports	2022-08-01 19:50:00 -04:00
virtio	virtio: fatures, fixes	2022-08-12 09:50:34 -07:00
Makefile	s390: remove pointless drivers-y in drivers/s390/Makefile	2019-09-16 13:21:51 +02:00