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Description of problem:
libvirt should forbid set current cpu to 0
Version-Release number of selected component (if applicable):
libvirt-1.2.17-13.el7_2.2.x86_64
How reproducible:
100%
Steps to Reproduce:
1. prepare a inactive guest:
# virsh list --all
Id Name State
----------------------------------------------------
- RHEL71-lhuang-novhost shut off
2. edit guest xml and make current cpu to 0:
<vcpu placement='static' current='0'>16</vcpu>
# virsh edit RHEL71-lhuang-novhost
error: XML document failed to validate against schema: Unable to validate doc against /usr/share/libvirt/schemas/domain.rng
Extra element vcpu in interleave
Invalid sequence in interleave
Element domain failed to validate content
Failed. Try again? [y,n,i,f,?]:
Domain RHEL71-lhuang-novhost XML configuration edited.
3. check xml:
# virsh dumpxml RHEL71-lhuang-novhost | grep current
<currentMemory unit='KiB'>1153433</currentMemory>
<vcpu placement='static' current='0'>16</vcpu>
4. try to start this guest:
# virsh start RHEL71-lhuang-novhost
error: Failed to start domain RHEL71-lhuang-novhost
error: internal error: got wrong number of vCPU pids from QEMU monitor. got 16, wanted 0
5. try some command:
# virsh vcpupin RHEL71-lhuang-novhost
error: ncpumaps in virDomainGetVcpuPinInfo must be greater than zero
# virsh vcpuinfo RHEL71-lhuang-novhost
error: ncpumaps in virDomainGetVcpuPinInfo must be greater than zero
Actual results:
libvirt allow set current vcpu to 0, but it doesn't make sense
Expected results:
forbid it
Additional info:
commit b3c91b8a50ac0d772f883e737252202d48658139
Author: Peter Krempa <pkrempa>
Date: Wed Jan 6 16:27:45 2016 +0100
qemu: process: Disallow VMs with 0 vcpus
Counterintuitively the user would end up with a VM with maximum number
of vCPUs available.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1290324
v1.3.1-44-gb3c91b8
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.
https://rhn.redhat.com/errata/RHSA-2016-2577.html