Ubuntu18.04 - KVM on S390 - Multiple epoch facility bugs
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Ubuntu on IBM z Systems |
Fix Released
|
High
|
Canonical Kernel Team | ||
linux (Ubuntu) |
Fix Released
|
High
|
Canonical Kernel Team | ||
Bionic |
Fix Released
|
High
|
Canonical Kernel Team |
Bug Description
The bionic 4.15 kernel contains KVM/s390 support for the multiple epoch facility.
This code has some bugs which can result in hanging guests when running the guest on a z14 with a recent guest kernel (containing 6e2ef5e4f6cc573
The following upstream commits are necessary to fix the multi epoch facility
0e7def5fb0dc KVM: s390: provide only a single function for setting the tod (fix SCK)
1575767ef3cf KVM: s390: consider epoch index on TOD clock syncs
d16b52cb9cdb KVM: s390: consider epoch index on hotplugged CPUs
5fe01793dd95 KVM: s390: take care of clock-comparator sign control
As an alternative 4.15.8 also contains these fixes.
---uname output---
4.15
---Additional Hardware Info---
Z14 LPAR
Machine Type = IBM z14
---System Hang---
A simple test case to trigger the hang of guests:
qemu-system-s390x -drive file=/data/
it hangs
just before printing the network dialog.
tags: | added: architecture-s39064 bugnameltc-165694 severity-high targetmilestone-inin1804 |
Changed in ubuntu: | |
assignee: | nobody → Skipper Bug Screeners (skipper-screen-team) |
affects: | ubuntu → linux (Ubuntu) |
summary: |
- KVM: multiple epoch facility bugs + Ubuntu18.04 - KVM on S390 - Multiple epoch facility bugs |
Changed in linux (Ubuntu): | |
importance: | Undecided → High |
status: | New → Triaged |
Changed in linux (Ubuntu Bionic): | |
assignee: | Skipper Bug Screeners (skipper-screen-team) → Canonical Kernel Team (canonical-kernel-team) |
tags: | added: kernel-da-key |
Changed in ubuntu-z-systems: | |
status: | Triaged → Fix Committed |
upstream mainline kernel:
$ git tag --contains 0e7def5fb0dc
v4.16-rc4
v4.16-rc5
$ git tag --contains 1575767ef3cf
v4.16-rc4
v4.16-rc5
$ git tag --contains d16b52cb9cdb
v4.16-rc4
v4.16-rc5
$ git tag --contains 5fe01793dd95
v4.16-rc4
v4.16-rc5