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.
Bug 645365 - KVM: Implement emulation of emulated virtual PMU
Summary: KVM: Implement emulation of emulated virtual PMU
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: kernel
Version: 6.0
Hardware: Unspecified
OS: Unspecified
low
medium
Target Milestone: rc
: 6.3
Assignee: Gleb Natapov
QA Contact: Virtualization Bugs
Jiri Herrmann
URL:
Whiteboard:
Depends On:
Blocks: 580953 747683 756082 758829 1300182
TreeView+ depends on / blocked
 
Reported: 2010-10-21 12:13 UTC by Jes Sorensen
Modified: 2016-12-12 18:53 UTC (History)
11 users (show)

Fixed In Version: kernel-2.6.32-250.el6
Doc Type: Bug Fix
Doc Text:
KVM can now virtualize Intel's performance monitoring unit (PMU) to allow virtual machines to use performance monitoring. Note that the -cpu host flag must be set when using this feature. BENEFITS: With this feature, Red Hat virtualization customers running Red Hat Enterprise Linux 6 guests can use the CPU's PMU counter while using the performance tool for profiling. The virtual performance monitoring unit feature allows virtual machine users to identify sources of performance problems in their guests, thereby improving the ability to profile a KVM guest from the host. This feature is a Technology Preview in Red Hat Enterprise Linux 6.3 and is only supported with guests running Red Hat Enterprise Linux 6.
Clone Of:
: 747683 (view as bug list)
Environment:
Last Closed: 2012-06-20 07:36:38 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2012:0862 0 normal SHIPPED_LIVE Moderate: Red Hat Enterprise Linux 6 kernel security, bug fix and enhancement update 2012-06-20 12:55:00 UTC

Description Jes Sorensen 2010-10-21 12:13:27 UTC 
Description of problem:
We need to provide support for a fully emulated PMU, in order to support operating systems where we cannot easily add para-virt support for it (eg. windows), and run tools such as vtune on unmodified older guests.

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1.
2.
3.
  
Actual results:


Expected results:


Additional info:
This BZ depends on BZ 603758
Comment 2 RHEL Program Management 2011-01-07 03:56:08 UTC 
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
representative.
Comment 3 Suzanne Logcher 2011-01-07 16:12:54 UTC 
This request was erroneously denied for the current release of Red Hat
Enterprise Linux.  The error has been fixed and this request has been
re-proposed for the current release.
Comment 4 RHEL Program Management 2011-02-01 05:32:52 UTC 
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
representative.
Comment 5 RHEL Program Management 2011-02-01 18:47:52 UTC 
This request was erroneously denied for the current release of
Red Hat Enterprise Linux.  The error has been fixed and this
request has been re-proposed for the current release.
Comment 6 Jes Sorensen 2011-09-01 09:08:20 UTC 
Given Avi is working on this, hand over the BZ
Comment 8 Aristeu Rozanski 2012-03-07 14:43:12 UTC 
Patch(es) available on kernel-2.6.32-250.el6
Comment 11 Ademar Reis 2012-04-17 00:05:14 UTC 
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
KVM can now virtualize a performance monitoring unit (vPMU) to allow virtual machines to use performance monitoring.

Additionally it supports Intel's "architectural PMU" which can be live-migrated across different host CPU versions, using the -cpu host flag.

BENEFITS:
Red Hat virtualization customers are now able to utilize performance monitoring in KVM guests seamlessly. The virtual performance monitoring feature allows virtual machine users to identify sources of performance problems in their guests, using their preferred pre-existing profiling tools that work on the host as well as the guest. This is in addition to the existing ability to profile a KVM guest from the host.

This feature is a Technology Preview in RHEL6.3
Comment 12 juzhang 2012-05-02 06:35:31 UTC 
We did vpmu functional testing with qemu-kvm-0.12.1.2-2.249.el6 on kernel-2.6.32-251.el6. did not find critical bugs
Comment 14 juzhang 2012-05-02 06:37:42 UTC 
According to comment12 and comment13, set this issue as verified.
Comment 16 errata-xmlrpc 2012-06-20 07:36:38 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2012-0862.html
Comment 17 Laura Novich 2012-06-21 11:10:31 UTC 
    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -1,6 +1,6 @@
 KVM can now virtualize a performance monitoring unit (vPMU) to allow virtual machines to use performance monitoring.
 
-Additionally it supports Intel's "architectural PMU" which can be live-migrated across different host CPU versions, using the -cpu host flag.
+The vPMU feature makes direct use of the CPU's PMU and as such is only supported on an Intel processor. Note that the -cpu host flag must be set when using this feature.
 
 BENEFITS:
 Red Hat virtualization customers are now able to utilize performance monitoring in KVM guests seamlessly. The virtual performance monitoring feature allows virtual machine users to identify sources of performance problems in their guests, using their preferred pre-existing profiling tools that work on the host as well as the guest. This is in addition to the existing ability to profile a KVM guest from the host.
Comment 18 Laura Novich 2012-06-21 11:31:00 UTC 
    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -1,6 +1,6 @@
-KVM can now virtualize a performance monitoring unit (vPMU) to allow virtual machines to use performance monitoring.
+KVM can now virtualize Intel's performance monitoring unit (vPMU) to allow virtual machines to use performance monitoring.
 
-The vPMU feature makes direct use of the CPU's PMU and as such is only supported on an Intel processor. Note that the -cpu host flag must be set when using this feature.
+Note that the -cpu host flag must be set when using this feature.
 
 BENEFITS:
 Red Hat virtualization customers are now able to utilize performance monitoring in KVM guests seamlessly. The virtual performance monitoring feature allows virtual machine users to identify sources of performance problems in their guests, using their preferred pre-existing profiling tools that work on the host as well as the guest. This is in addition to the existing ability to profile a KVM guest from the host.
Comment 19 Laura Novich 2012-06-21 11:47:18 UTC 
    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -1,4 +1,4 @@
-KVM can now virtualize Intel's performance monitoring unit (vPMU) to allow virtual machines to use performance monitoring.
+KVM can now virtualize Intel's performance monitoring unit (PMU) to allow virtual machines to use performance monitoring.
 
 Note that the -cpu host flag must be set when using this feature.
Comment 20 Laura Novich 2012-06-21 12:36:43 UTC 
    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -3,6 +3,6 @@
 Note that the -cpu host flag must be set when using this feature.
 
 BENEFITS:
-Red Hat virtualization customers are now able to utilize performance monitoring in KVM guests seamlessly. The virtual performance monitoring feature allows virtual machine users to identify sources of performance problems in their guests, using their preferred pre-existing profiling tools that work on the host as well as the guest. This is in addition to the existing ability to profile a KVM guest from the host.
+With this feature, Red Hat virtualization customers running Red Hat Enterprise Linux 6 guests can use the CPU's PMU counter while using the performance tool for profiling. The virtual performance monitoring unit feature allows virtual machine users to identify sources of performance problems in their guests, thereby improving the ability to profile a KVM guest from the host. 
 
-This feature is a Technology Preview in RHEL6.3+This feature is a Technology Preview in Red Hat Enterprise Linux 6.3 and is only supported with guests running Red Hat Enterprise Linux 6.
Note You need to log in before you can comment on or make changes to this bug.