Bug 1145293

Summary: VMs are created with tsc flag by default
Product: [Community] Virtualization Tools Reporter: noel
Component: virt-managerAssignee: Cole Robinson <crobinso>
Status: CLOSED DUPLICATE QA Contact:
Severity: medium Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: berrange, crobinso, gscrivan, noel, rbalakri
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Hardware: All   
OS: Unspecified   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2014-09-22 20:38:58 UTC Type: Bug
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Description noel 2014-09-22 18:38:00 UTC 
Description of problem:

Virtual Machines are created with the tsc flag by default.
Up to libvirt 1.2.7, that was no problem as there was no mapping
to a CPU flag. [1]
Now, the feature is mapped to the flag (from /proc/cpuinfo) tsc_constant,
which is not available on all machines. Hence, the bevaviour of virt-manager
breaks the setups on many machines. The reason being, that all the VM definitions contain said tsc feature with policy="require". Also it is not possible to
create new VMs using virt-manager, as it includes said CPU feature by default, it's not possible to adjust the features during the setup and the setup starts the VM in the process of setting it up, hence the only option is to exit the setup without creating a new machine.

The fix for this is to not create machines using virt-manager, but write ones own XML definitions and creating domains from those with virsh's "create" command.
To fix already existing machines, it is necessary to delete the line containing the tsc feature in the cpu section of the XML VM definition.

[1] https://gitorious.org/libvirt/libvirt/commit/fba6bc47cbcabbe08d42279691efb0dff3b9c997

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

libvirt 1.2.8
virt-manager 1.1.0

How reproducible:

Always.

Steps to Reproduce:
1. Use libvirt 1.2.8 and virt-manager 1.1.0
2. Try to create a VM using virt-manager on a machine using said libvirt version.
3. Fail.
Comment 1 noel 2014-09-22 20:08:23 UTC 
It works if CPU configuration "qemu64" is specified. Using "copy host configuration" causes the problem.
I think it's a bug in the logic for choosing the correct CPU type.
Because of that, the severity is downgraded to medium.
Comment 2 Cole Robinson 2014-09-22 20:38:58 UTC 
This is fixed upstream and will be in the next release:

commit b0d5198b7abdb1ac48709b991d84ca3259ecb9aa
Author: Cole Robinson <crobinso>
Date:   Sat Sep 20 20:40:05 2014 -0400

    virt-manager: Switch 'Copy host' to use host-model (bz 1133155)

*** This bug has been marked as a duplicate of bug 1133155 ***