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

[Alexandre DERUMIER]

>> But you do have to set the polling interval to use the feature. 

Ok thanks Luiz.
The problem was that we didn't set polling interval on migration only (on 
target qemu).

Thanks again !

Alexandre

----- Mail original -----
De: "Luiz Capitulino" <address@hidden>
À: "aderumier" <address@hidden>
Cc: "qemu-devel" <address@hidden>, "dietmar" <address@hidden>
Envoyé: Mardi 10 Mars 2015 14:30:20
Objet: Re: [Qemu-devel] balloon stats not working if qemu is started with 
-machine option

On Mon, 9 Mar 2015 08:04:54 +0100 (CET) 
Alexandre DERUMIER <address@hidden> 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" <address@hidden> 
> À: "qemu-devel" <address@hidden>, "Luiz Capitulino" <address@hidden> 
> Cc: "dietmar" <address@hidden> 
> 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 
>