** Description changed:
+ == Justification ==
+ The s390x early machine detection code check will set all the uknown
+ hypervisors to z/VM, this will cause crash for any non KVM, z/VM
+ system.
+
+ == Fixes ==
+ 03aa047e (s390/early: improve machine detection)
+ Patch can be cherry-picked into Bionic kernel.
+
+ Instead of setting all the other hypervisors to z/VM, it will only set
+ MACHINE_FLAG_VM if it matches the case.
+
+ == Tests ==
+ A test kernel could be found here:
+ https://people.canonical.com/~phlin/kernel/lp-1829972-s390x-early/
+
+ Boot tested on a s390x KVM node and verified by IBM as well.
+
+ == Regression Potential ==
+ Low, this just improves the detection logic and the changes are
+ specific to s390x.
+
+
+ == Original Bug Report ==
+
This kernel commit is requested to be included into the bionic's 4.15.0
LTS kernel:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=03aa047ef2db4985e444af6ee1c1dd084ad9fb4c
s390/early: improve machine detection
Right now the early machine detection code check stsi 3.2.2 for "KVM"
and set MACHINE_IS_VM if this is different. As the console detection
uses diagnose 8 if MACHINE_IS_VM returns true this will crash Linux
early for any non z/VM system that sets a different value than KVM.
So instead of assuming z/VM, do not set any of MACHINE_IS_LPAR,
MACHINE_IS_VM, or MACHINE_IS_KVM.
This is required for a dedicated SSC exploiter
** Changed in: linux (Ubuntu Bionic)
Assignee: (unassigned) => Po-Hsu Lin (cypressyew)
** Changed in: linux (Ubuntu Bionic)
Status: New => In Progress
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https://bugs.launchpad.net/bugs/1829972
Title:
Require improved hypervisor detection patch in Ubuntu 18.04
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