Re: [Qemu-devel] balloon stats not working if qemu is started with -machine option

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 9 Mar 2015 08:04:54 +0100 (CET)
Alexandre DERUMIER <aderumier@odiso.com> wrote:

> I have forgot to said that we don't setup pooling interval manually. (which seem to works fine without -machine)
> 
> 
> Now,if I setup guest-stats-polling-interval with qom-set,
> it seem to works fine with -machine option.

Setting the polling interval is a required step.

The output you sent seems to indicate that the guest sent a stats update
to the host unilaterally and those values seem buggy. I can investigate
it if you provide full details (guest command-line plus full QMP
command sequence). But you do have to set the polling interval to use
the feature.

> 
> 
> 
> ----- Mail original -----
> De: "aderumier" <aderumier@odiso.com>
> À: "qemu-devel" <qemu-devel@nongnu.org>, "Luiz Capitulino" <lcapitulino@redhat.com>
> Cc: "dietmar" <dietmar@proxmox.com>
> Envoyé: Lundi 9 Mars 2015 07:49:22
> Objet: [Qemu-devel] balloon stats not working if qemu is started with	-machine option
> 
> Hi, 
> 
> I have noticed that balloon stats are not working if a qemu guest is started with -machine option. 
> 
> (-machine pc, or any version) . Tested of qemu 1.7,2.1 && 2.2 
> 
> 
> When the guest is starting (balloon driver not yet loaded) 
> 
> $VAR1 = { 
> 'last-update' => 0, 
> 'stats' => { 
> 'stat-free-memory' => -1, 
> 'stat-swap-in' => -1, 
> 'stat-total-memory' => -1, 
> 'stat-major-faults' => -1, 
> 'stat-minor-faults' => -1, 
> 'stat-swap-out' => -1 
> } 
> }; 
> 
> 
> then 
> 
> when the guest has loaded his driver 
> 
> $VAR1 = { 
> 'last-update' => 1425882998, 
> 'stats' => { 
> 'stat-free-memory' => -1, 
> 'stat-swap-in' => '4039065379203448832', 
> 'stat-total-memory' => -1, 
> 'stat-major-faults' => -1, 
> 'stat-minor-faults' => -1, 
> 'stat-swap-out' => '-6579759055588294656' 
> } 
> }; 
> 
> $VAR1 = { 
> 'last-update' => 1425882998, 
> 'stats' => { 
> 'stat-free-memory' => -1, 
> 'stat-swap-in' => '4039065379203448832', 
> 'stat-total-memory' => -1, 
> 'stat-major-faults' => -1, 
> 'stat-minor-faults' => -1, 
> 'stat-swap-out' => '-6579759055588294656' 
> } 
> }; 
> 
> 
> $VAR1 = { 
> 'last-update' => 1425882998, 
> 'stats' => { 
> 'stat-free-memory' => -1, 
> 'stat-swap-in' => '4039065379203448832', 
> 'stat-total-memory' => -1, 
> 'stat-major-faults' => -1, 
> 'stat-minor-faults' => -1, 
> 'stat-swap-out' => '-6579759055588294656' 
> } 
> }; 
> 
> 
> It's seem that a some stats are retrieved, but last-update don't increment. 
> Removing the machine option resolve the problem. 
> 
> 
> I'm working with proxmox team, and a lot of user have reported balloning bug, because we pass the -machine option when are a doing live migration. 
> 
> I'm surprised that -machine pc also have this bug. (Isn't it supposed to be the default machine config ?) 
> 
> 
> 
> 
> here the sample command line: 
> 
> 
> /usr/bin/kvm -id 150 -chardev socket,id=qmp,path=/var/run/qemu-server/150.qmp,server,nowait -mon chardev=qmp,mode=control -vnc unix:/var/run/qemu-server/150.vnc,x509,password -pidfile /var/run/qemu-server/150.pid -daemonize -smbios type=1,manufacturer=dell,version=1,product=3,uuid=f0686bfb-50b8-4d31-a4cb-b1cf60eeb648 -name debianok -smp 1,sockets=2,cores=1,maxcpus=2 -nodefaults -boot menu=on,strict=on,reboot-timeout=1000 -vga cirrus -cpu kvm64,+lahf_lm,+x2apic,+sep -m 4096 -k fr -device piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2 -device usb-tablet,id=tablet,bus=uhci.0,port=1 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -iscsi initiator-name=iqn.1993-08.org.debian.01.24b0d01a62a3 -drive file=/var/lib/vz/images/150/vm-150-disk-1.raw,if=none,id=drive-virtio0,format=raw,aio=native,cache=none -device virtio-blk-pci,drive=drive-virtio0,id=virtio0,bus=pci.0,addr=0xa,bootindex=100 -netdev type=tap,id=net0,ifname=tap150i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown,vhost=on -device virtio-net-pci,mac=76:EF:E9:ED:9D:41,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300 -machine pc 
>