Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Description of problem:
Upstream qemu commit 910628f39676ee65211727245809eec7ca4d75f5 adds
POPCNT to qemu64/qemu32. This can break migration when using
these guest models should migration be attempted to a cpu lacking
this feature.
How reproducible:
# /usr/libexec/qemu-kvm -cpu ?dump
Actual results:
x86 [qemu64] QEMU Virtual CPU version 0.12.1
:
feature_ecx 00802001 (popcnt cx16 pni|sse3)
x86 [qemu32] QEMU Virtual CPU version 0.12.1
:
feature_ecx 00800001 (popcnt pni|sse3)
Expected results:
"popcnt" should not be present.
Additional info:
The addition of popcnt to what is intended as a least common
denominator seems rather odd, as only select CPUs support this
feature. This was specifically enabled by the commit called
out above and understanding what motivated this change needs
to be part of the case resolution.
Comment 2RHEL Program Management
2010-07-26 17:37:42 UTC
This issue has been proposed when we are only considering blocker
issues in the current Red Hat Enterprise Linux release.
** If you would still like this issue considered for the current
release, ask your support representative to file as a blocker on
your behalf. Otherwise ask that it be considered for the next
Red Hat Enterprise Linux release. **
Tested with qemu-kvm-0.12.1.2-2.108.el6,
1. # /usr/libexec/qemu-kvm -cpu ?dump
x86 cpu64-rhel5 QEMU Virtual CPU version (cpu64-rhel5)
:
feature_ecx 00000001 (pni|sse3)
:
x86 cpu64-rhel6 QEMU Virtual CPU version (cpu64-rhel6)
:
feature_ecx 00002001 (cx16 pni|sse3)
:
2. Boot guest with -M rhel6.0.0 & -M rhel5.5.0 & -M rhel5.4.4 & -M rhel5.4.0, guest can be boot up successfully with related cpu model.
cmd:
# /usr/libexec/qemu-kvm -m 4G -smp 2 -monitor stdio -drive file=/home/RHEL-Server-6.0-64-virtio.qcow2,if=none,format=qcow2,boot=on,cache=none,id=test -device virtio-blk-pci,drive=test -device virtio-net-pci,mac=20:20:20:12:23:15,netdev=hostnet0 -netdev tap,script=/etc/qemu-ifup,vhost=on,id=hostnet0 -usbdevice tablet -vnc :10 -M xxxx
Based on above, change status to verified.
Comment 10releng-rhel@redhat.com
2010-11-10 21:26:56 UTC
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.
Description of problem: Upstream qemu commit 910628f39676ee65211727245809eec7ca4d75f5 adds POPCNT to qemu64/qemu32. This can break migration when using these guest models should migration be attempted to a cpu lacking this feature. How reproducible: # /usr/libexec/qemu-kvm -cpu ?dump Actual results: x86 [qemu64] QEMU Virtual CPU version 0.12.1 : feature_ecx 00802001 (popcnt cx16 pni|sse3) x86 [qemu32] QEMU Virtual CPU version 0.12.1 : feature_ecx 00800001 (popcnt pni|sse3) Expected results: "popcnt" should not be present. Additional info: The addition of popcnt to what is intended as a least common denominator seems rather odd, as only select CPUs support this feature. This was specifically enabled by the commit called out above and understanding what motivated this change needs to be part of the case resolution.