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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
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.
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.
Given Avi is working on this, hand over the BZ
Patch(es) available on kernel-2.6.32-250.el6
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
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
According to comment12 and comment13, set this issue as verified.
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
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.
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.
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.
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.