Since this seems to be broken on all Distributions as soon as the triggering
combination of kernel/glibc is present I think we'd want to open that up to
upstream qemu for a wider discussion and to also hit the ppc64 architecture
experts.
Furthermore I'm not entirely sure if this needs to be fixed in qemu, it
might instead be the case that instead a fix is needed in glibc.
Therefore I'm adding a qemu (upstream) bug task for now to have the bug
reported there as well (might be worth for awareness anyway) - but
chances are that after some debugging it will turn out to become a glibc
issue instead.
If only I could break this test out of kvm ioctl into something simpler,
then we could then properly file against glibc ....
** Also affects: glibc (Ubuntu)
Importance: Undecided
Status: New
** Also affects: qemu
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1920784
Title:
qemu-system-ppc64le fails with kvm acceleration
Status in QEMU:
New
Status in The Ubuntu-power-systems project:
New
Status in glibc package in Ubuntu:
New
Status in qemu package in Ubuntu:
Confirmed
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
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1920784/+subscriptions
