Power9: Ubuntu18.04: qemu gets crashed with cap-ibs="workaround" (kvm)

== Comment: #0 - Satheesh Rajendran <email address hidden> - 2018-04-04 08:34:47 ==
---Problem Description---
qemu gets crashed with cap-ibs="workaround"

---uname output---
4.15.0-14-generic #15-Ubuntu SMP Mon Apr 2 19:47:43 UTC 2018

Machine Type = power9 boston 2.2 (pvr 004e 1202)

---Debugger---
A debugger is not configured

---Steps to Reproduce---
 Boot a guest with machine capability cap-ibs=workaround, qemu-kvm crashes during guest booting.

#kvm -M pseries,cap-cfpc=workaround,cap-sbbc=workaround,cap-ibs=workaround -monitor stdio -serial /dev/pts/7 -enable-kvm -nographic -vga none /ho/sath/ubuntu-18.04-ppc64le.qcow2
QEMU 2.11.1 monitor - type 'help' for more information
(qemu)
(qemu) qemu-system-ppc64: /build/qemu-MNXTuJ/qemu-2.11+dfsg/hw/ppc/spapr_hcall.c:1703: h_get_cpu_characteristics: Assertion `safe_indirect_branch == SPAPR_CAP_BROKEN' failed.
Aborted

This upstream patch will fix the issue, https://github.com/open-power-host-os/qemu/commit/4f5b039d2bf9bb26b6e26a3dc65da36fe970cba9

Contact Information = <email address hidden>

Userspace tool common name: qemu-kvm 1:2.11+dfsg-1ubuntu5

The userspace tool has the following bit modes: both

Userspace rpm: qemu-kvm 1:2.11+dfsg-1ubuntu5

Userspace tool obtained from project website: na

*Additional Instructions for <email address hidden>:
-Attach ltrace and strace of userspace application.

== Comment: #3 - Satheesh Rajendran <email address hidden> - 2018-04-04 08:57:22 ==
This commit fixes the issue:

commit 4f5b039d2bf9bb26b6e26a3dc65da36fe970cba9
Author: Suraj Jitindar Singh <email address hidden>
Date: Fri Feb 16 13:33:27 2018 +1100

    ppc/spapr-caps: Disallow setting workaround for spapr-cap-ibs

    The spapr-cap cap-ibs can only have values broken or fixed as there is
    no explicit workaround required. Currently setting the value workaround
    for this cap will hit an assert if the guest makes the hcall
    h_get_cpu_characteristics.

    Report an error when attempting to apply the setting with a more helpful
    error message.

    Reported-by: Satheesh Rajendran <email address hidden>
    Signed-off-by: Suraj Jitindar Singh <email address hidden>
    Signed-off-by: David Gibson <email address hidden>