Bug 1010881

Summary: backport vcpu soft limit warning
Product: Red Hat Enterprise Linux 7 Reporter: Andrew Jones <drjones>
Component: qemu-kvmAssignee: Andrew Jones <drjones>
Status: CLOSED CURRENTRELEASE QA Contact: Virtualization Bugs <virt-bugs>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.0CC: acathrow, huding, juzhang, michen, virt-maint, xfu
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: qemu-kvm-1.5.3-9.el7 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
: 1010882 (view as bug list) Environment:
Last Closed: 2014-06-13 11:22:00 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 1010882    

Description Andrew Jones 2013-09-23 09:01:19 UTC
Backport 972fc544b6034 "kvm: warn if num cpus is greater than num recommended" from uq/master in order to help enforce the recommended max vcpu limit.

Comment 1 Miroslav Rezanina 2013-10-10 11:33:59 UTC
Fix included in qemu-kvm-1.5.3-9.el7

Comment 3 huiqingding 2013-12-18 09:29:11 UTC
Reproduce this bug using the following version:
qemu-kvm-1.5.3-8.el7.x86_64
kernel-3.10.0-63.el7.x86_64

Steps to Reproduce:

1. Start a guest with 255 vcpus
# /usr/libexec/qemu-kvm -M pc -cpu SandyBridge -enable-kvm -m 2048 -smp 255 -name rhel7 -uuid 6afa5f93-2d4f-420f-81c6-e5fdddbd1c83 -drive file=/home/RHEL-Server-7.0-64-virtio.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,serial=40c061dd-5d60-4fc5-865f-55db700407f0,werror=stop,rerror=stop,aio=threads -device virtio-blk-pci,scsi=off,drive=drive-virtio-disk0,id=virtio-disk0  -vnc :1 -monitor stdio -spice port=5900,disable-ticketing  -qmp tcp:0:4445,server,nowait -netdev tap,id=hostnet0,ifname=guest13,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown,vhost=on -device virtio-net,netdev=hostnet0,mac=54:52:1b:35:3c:16,id=test

Actual results:
After step1, there is no warning information.

Comment 4 huiqingding 2013-12-18 09:32:50 UTC
Verify this bug using the following version:
qemu-kvm-1.5.3-21.el7.x86_64
kernel-3.10.0-63.el7.x86_64

Steps to Reproduce:

1. Start a guest with 255 vcpus
# /usr/libexec/qemu-kvm -M pc -cpu SandyBridge -enable-kvm -m 2048 -smp 255 -name rhel7 -uuid 6afa5f93-2d4f-420f-81c6-e5fdddbd1c83 -drive file=/home/RHEL-Server-7.0-64-virtio.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,serial=40c061dd-5d60-4fc5-865f-55db700407f0,werror=stop,rerror=stop,aio=threads -device virtio-blk-pci,scsi=off,drive=drive-virtio-disk0,id=virtio-disk0  -vnc :1 -monitor stdio -spice port=5900,disable-ticketing  -qmp tcp:0:4445,server,nowait -netdev tap,id=hostnet0,ifname=guest13,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown,vhost=on -device virtio-net,netdev=hostnet0,mac=54:52:1b:35:3c:16,id=test

Actual results:
After step1, there are the following warning information:
Warning: Number of SMP cpus requested (255) exceeds the recommended cpus supported by KVM (160)
Warning: Number of hotpluggable cpus requested (255) exceeds the recommended cpus supported by KVM (160)
QEMU 1.5.3 monitor - type 'help' for more information
(qemu)

Based on the above result, I think this bug is fixed.

Comment 6 Ludek Smid 2014-06-13 11:22:00 UTC
This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.