Public bug reported:

== Comment: #0 - Satheesh Rajendran <> - 2018-04-04 08:58:54 
---Problem Description---
backport needed for spectre/meltdown mitigation machine type qemu patches

For mitigating spectre/meltdown cpu vulnerability, qemu implements the machine 
capabilities  cfpc,sbbc,ibs, which are present in the current qemu, but the 
default values of it would be broken(no mitigation) even fixes in hw/fw/sw is 

Qemu further introduces  machine type variant pseries-2.12-sxxm which
would set bydefault below capabilities without need of explicitly
mentioning it, if mitigation is available in fw/sw. which is missing
needs a backport.

kvm -M pseries,help 2>&1|egrep 'cap-cfpc|cap-sbbc|cap-ibs
pseries-bionic.cap-sbbc=string (Speculation Barrier Bounds Checking (broken, 
workaround, fixed)(null))
pseries-bionic.cap-cfpc=string (Cache Flush on Privilege Change (broken, 
workaround, fixed)(null))
pseries-bionic.cap-ibs=string (Indirect Branch Serialisation (broken, 
workaround, fixed)(null))

Upstream qemu Commits:

813f3cf655 ppc/spapr-caps: Define the pseries-2.12-sxxm machine type
c76c0d3090 ppc/spapr-caps: Convert cap-ibs to custom spapr-cap
aaf265ffde ppc/spapr-caps: Convert cap-sbbc to custom spapr-cap
f27aa81e72 ppc/spapr-caps: Convert cap-cfpc to custom spapr-cap
87175d1bc5 ppc/spapr-caps: Add support for custom spapr_capabilities
cb931c2108 target/ppc: Check mask when setting cap_ppc_safe_indirect_branch

Contact Information = 
---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) 
A debugger is not configured
Userspace tool common name: qemu-kvm                               
The userspace tool has the following bit modes: both 

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

Userspace tool obtained from project website:  na 
*Additional Instructions for
-Attach ltrace and strace of userspace application.

** Affects: qemu (Ubuntu)
     Importance: Undecided
     Assignee: Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage)
         Status: New

** Tags: architecture-ppc64le bugnameltc-166426 severity-critical 

** Tags added: architecture-ppc64le bugnameltc-166426 severity-critical

** Changed in: ubuntu
     Assignee: (unassigned) => Ubuntu on IBM Power Systems Bug Triage 

** Package changed: ubuntu => qemu (Ubuntu)

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  backport needed for spectre/meltdown mitigation machine type qemu
  patches (kvm)

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