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 1258339 - qemu-kvm boot up failed with "can't use already busy memdev"
Summary: qemu-kvm boot up failed with "can't use already busy memdev"
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: qemu-kvm-rhev
Version: 7.2
Hardware: x86_64
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: Eduardo Habkost
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2015-08-31 06:37 UTC by ShupingCui
Modified: 2016-05-16 04:08 UTC (History)
10 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-08-31 18:39:43 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

Description ShupingCui 2015-08-31 06:37:08 UTC 
Description of problem:
qemu-kvm boot up failed with "can't use already busy memdev"

Version-Release number of selected component (if applicable):
# rpm -q qemu-kvm-rhev
qemu-kvm-rhev-2.3.0-21.el7.x86_64


How reproducible:
100%

Steps to Reproduce:
1. boot up vm with one numa node
/bin/qemu-kvm \
    -S  \
    -name 'virt-tests-vm1'  \
    -sandbox off  \
    -machine pc  \
    -nodefaults  \
    -vga cirrus  \
    -chardev socket,id=qmp_id_qmpmonitor1,path=/tmp/monitor-qmpmonitor1-20150831-132748-EY9Ue1UE,server,nowait \
    -mon chardev=qmp_id_qmpmonitor1,mode=control  \
    -chardev socket,id=qmp_id_catch_monitor,path=/tmp/monitor-catch_monitor-20150831-132748-EY9Ue1UE,server,nowait \
    -mon chardev=qmp_id_catch_monitor,mode=control \
    -device pvpanic,ioport=0x505,id=idm5gMcB  \
    -chardev socket,id=serial_id_serial0,path=/tmp/serial-serial0-20150831-132748-EY9Ue1UE,server,nowait \
    -device isa-serial,chardev=serial_id_serial0  \
    -chardev socket,id=seabioslog_id_20150831-132748-EY9Ue1UE,path=/tmp/seabios-20150831-132748-EY9Ue1UE,server,nowait \
    -device isa-debugcon,chardev=seabioslog_id_20150831-132748-EY9Ue1UE,iobase=0x402 \
    -device ich9-usb-uhci1,id=usb1,bus=pci.0,addr=03 \
    -drive id=drive_image1,if=none,cache=none,snapshot=off,aio=native,format=qcow2,file=/mnt/nfs_images/RHEL-Server-7.2-64-virtio.qcow2 \
    -device virtio-blk-pci,id=image1,drive=drive_image1,bootindex=0,bus=pci.0,addr=04 \
    -device virtio-net-pci,mac=9a:c1:c2:c3:c4:c5,id=idkgc4ST,vectors=4,netdev=idFlR5jA,bus=pci.0,addr=05  \
    -netdev tap,id=idFlR5jA \
    -m 4096,slots=4,maxmem=32G \
    -object memory-backend-ram,size=4096M,host-nodes=0,policy=bind,id=mem-mem0 \
    -device pc-dimm,id=dimm-mem0,memdev=mem-mem0 \
    -smp 4,maxcpus=4,cores=2,threads=1,sockets=2  \
    -numa node,memdev=mem-mem0 \
    -cpu 'SandyBridge',+kvm_pv_unhalt \
    -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1  \
    -vnc :0  \
    -rtc base=utc,clock=host,driftfix=slew  \
    -boot order=cdn,once=c,menu=off,strict=off \
    -enable-kvm \
    -monitor stdio

2.
3.

Actual results:
(qemu) qemu-kvm: -device pc-dimm,id=dimm-mem0,memdev=mem-mem0: can't use already busy memdev: mem-mem0


Expected results:
boot up successfully

Additional info:
boot up successfully with "-numa node", no memdev option.
Comment 2 Eduardo Habkost 2015-08-31 18:39:43 UTC 
You are trying to use the same mem-dev for two different memory regions:
* The first 4GB, that's non-hotplug memory living in the first (only) NUMA node (-numa node,memdev=mem-mem0)
* Extra hotplugged memory beyond the first non-hotplug 4GB (-object pc-dimm)

You can't do that. If you want the guest to have just 4GB non-hotplug memory, simply don't use -object pc-dimm. If you want the guest to have 8GB (4GB non-hotplug and 4GB hotplug), you need two memory backend objects, 4GB each.
Note You need to log in before you can comment on or make changes to this bug.