[Bug 1920784] Re: qemu-system-ppc64le fails with kvm acceleration

From: "Christian Ehrhardt " <1920784@bugs.launchpad.net>
To: qemu-devel@nongnu.org
Subject: [Bug 1920784] Re: qemu-system-ppc64le fails with kvm acceleration
Date: Wed, 24 Mar 2021 06:44:50 -0000	[thread overview]
Message-ID: <161656829134.20059.463960810670452733.malone@wampee.canonical.com> (raw)
In-Reply-To: 161642496871.32717.8520198452991245606.malonedeb@soybean.canonical.com

And gladly this was only added in >=5.9 and we have Groovy (5.8) and
Hirsute (5.11) so only the Hirsute kernel is needed to adapt, but
further backports are not needed.

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https://bugs.launchpad.net/bugs/1920784

Title:
  qemu-system-ppc64le fails with kvm acceleration

Status in QEMU:
  Invalid
Status in The Ubuntu-power-systems project:
  Confirmed
Status in glibc package in Ubuntu:
  Invalid
Status in linux package in Ubuntu:
  Confirmed
Status in qemu package in Ubuntu:
  Invalid

Bug description:
  (Suspected glibc issue!)

  qemu-system-ppc64(le) fails when invoked with kvm acceleration with
  error "illegal instruction"

  > qemu-system-ppc64(le) -M pseries,accel=kvm

  Illegal instruction (core dumped)

  In dmesg:

  Facility 'SCV' unavailable (12), exception at 0x7624f8134c0c,
  MSR=900000000280f033

  Version-Release number of selected component (if applicable):
  qemu 5.2.0 
  Linux kernel 5.11
  glibc 2.33
  all latest updates as of submitting the bug report

  How reproducible:
  Always

  Steps to Reproduce:
  1. Run qemu with kvm acceleration

  Actual results:
  Illegal instruction

  Expected results:
  Normal VM execution

  Additional info:
  The machine is a Raptor Talos II Lite with a Sforza V1 8-core, but was also observed on a Raptor Blackbird with the same processor.

  This was also observed on Fedora 34 beta, which uses glibc 2.33
  Also tested on ArchPOWER (unofficial port of Arch Linux for ppc64le) with glibc 2.33
  Fedora 33 and Ubuntu 20.10, both using glibc 2.32 do not have this issue, and downgrading the Linux kernel from 5.11 to 5.4 LTS on ArchPOWER solved the problem. Kernel 5.9 and 5.10 have the same issue when combined with glibc2.33

  ProblemType: Bug
  DistroRelease: Ubuntu 21.04
  Package: qemu-system 1:5.2+dfsg-6ubuntu2
  ProcVersionSignature: Ubuntu 5.11.0-11.12-generic 5.11.0
  Uname: Linux 5.11.0-11-generic ppc64le
  .sys.firmware.opal.msglog: Error: [Errno 13] Permission denied: '/sys/firmware/opal/msglog'
  ApportVersion: 2.20.11-0ubuntu60
  Architecture: ppc64el
  CasperMD5CheckResult: pass
  CurrentDesktop: Unity:Unity7:ubuntu
  Date: Mon Mar 22 14:48:39 2021
  InstallationDate: Installed on 2021-03-22 (0 days ago)
  InstallationMedia: Ubuntu-Server 21.04 "Hirsute Hippo" - Alpha ppc64el (20210321)
  KvmCmdLine: COMMAND         STAT  EUID  RUID     PID    PPID %CPU COMMAND
  ProcKernelCmdLine: root=UUID=f3d03315-0944-4a02-9c87-09c00eba9fa1 ro
  ProcLoadAvg: 1.20 0.73 0.46 1/1054 6071
  ProcSwaps:
   Filename				Type		Size		Used		Priority
   /swap.img                               file		8388544		0		-2
  ProcVersion: Linux version 5.11.0-11-generic (buildd@bos02-ppc64el-002) (gcc (Ubuntu 10.2.1-20ubuntu1) 10.2.1 20210220, GNU ld (GNU Binutils for Ubuntu) 2.36.1) #12-Ubuntu SMP Mon Mar 1 19:26:20 UTC 2021
  SourcePackage: qemu
  UpgradeStatus: No upgrade log present (probably fresh install)
  VarLogDump_list: total 0
  acpidump:

  cpu_cores: Number of cores present = 8
  cpu_coreson: Number of cores online = 8
  cpu_smt: SMT=4

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