Bug 610787

Additional info:
I tried with virtio-win-1.1.6-1, windows 2003 x64 does work, windows 7 and
windows 2008 R2 does not work.

Note that you need to run the window service in order to get statistics.
Vadim, please add the details

"blnsvr.exe -i" to install the service
"blnsvr.exe -u" to uninstall the service

(In reply to comment #6)
> "blnsvr.exe -i" to install the service
> "blnsvr.exe -u" to uninstall the service    

Guest:windows 2008 R2

virtio-win-1.1.6-1:

{"execute":"query-balloon"}
{"return": {"actual": 4294967296, "mem_swapped_in": 0, "minor_page_faults": 0, "mem_swapped_out": 0, "free_mem": 3688632320, "major_page_faults": 0, "total_mem": 4294545408}}
{"execute":"balloon","arguments":{"value":3000000000}}
{"return": {}}
{"execute":"query-balloon"}
{"return": {"actual": 4288675840, "mem_swapped_in": 0, "minor_page_faults": 0, "mem_swapped_out": 0, "free_mem": 3603152896, "major_page_faults": 0, "total_mem": 4294545408}}

virtio-win-1.1.7-1:
{"execute":"query-balloon"}
{"return": {"actual": 4294967296, "mem_swapped_in": 1959}}
{"execute":"balloon","arguments":{"value":3000000000}}
{"return": {}}
{"execute":"query-balloon"}
{"return": {"actual": 4282384384, "mem_swapped_in": 0}}
{"execute":"query-balloon"}
{"return": {"actual": 4280287232, "mem_swapped_in": 0}}

I don't see any problem here. You cannot inflate balloon as big as you wish. Ballooning is a non-paged memory allocation operation. Non-paged memory is a very limited resource and nobody can guarantee that you will get as much as you asked. After all, playing with balloon means playing against OS, its Memory Manager, and other drivers.
You can get a better picture when looking at Performance Monitor while inflating/deflating balloon.

Best regards,
Vadim.

Guest: windows 2008 R2
Driver:virtio-win-1.1.7-1:
kernel-2.6.32-37.el6.x86_64
qemu-kvm-0.12.1.2-2.90.el6.x86_64

CLI:
/usr/libexec/qemu-kvm -m 4G -smp 2 -cpu qemu64,+x2apic -usbdevice tablet -drive file=/home/win2008r2-64-virtio.qcow2,if=none,id=drive-ide0-0-0,format=qcow2,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0  -netdev tap,id=hostnet0,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,mac=0a:00:34:3F:20:1A,bus=pci.0 -uuid 1234c27c-e6e3-4e67-95da-8dd0a8891cc4 -rtc-td-hack -no-kvm-pit-reinjection -monitor stdio -name win08R2 -device virtio-balloon-pci,bus=pci.0  -qmp tcp:0:4444,server,nowait -vnc :1 -boot c

reproduce steps:

1.Check balloon info from qmp
{"execute":"query-balloon"}
{"return": {"actual": 4294967296, "mem_swapped_in": 0}}

2.Check top info
 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                         
12795 root      20   0 4512m 4.0g 3044 S  5.9 52.9   0:58.00 qemu-kvm 

3.Check Performance tab in Task manager
Physical Memory(MB)
Total:4095
Cached:176
Available: 3576
Free:3404

4. Evict windows memory using qmp
{"execute":"balloon","arguments":{"value":2048000000}}
5.check balloon info twice
{"execute":"query-balloon"}
{"return": {"actual": 4263510016, "mem_swapped_in": 0}}
{"execute":"query-balloon"}
{"return": {"actual": 4261412864, "mem_swapped_in": 0}}

6.top info
 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                         
12795 root      20   0 4512m 4.0g 3048 S  9.9 52.5   1:10.59 qemu-kvm 
7. Check Performance tab in Task manager
Physical Memory(MB)
Total:4095
Cached:190
Available: 3559
Free:3377

From above steps, we found there is no abvious difference on RES of top and Available item in Task manager after evict windows guest memory from "4294967296" to "2048000000".

You may compare test result of windows xp x86 from https://bugzilla.redhat.com/show_bug.cgi?id=582165#c8.

(In reply to comment #7)
> (In reply to comment #6)
> > "blnsvr.exe -i" to install the service
> > "blnsvr.exe -u" to uninstall the service    
> 
> Guest:windows 2008 R2
> 
> virtio-win-1.1.6-1:
> 
> {"execute":"query-balloon"}
> {"return": {"actual": 4294967296, "mem_swapped_in": 0, "minor_page_faults": 0,
> "mem_swapped_out": 0, "free_mem": 3688632320, "major_page_faults": 0,
> "total_mem": 4294545408}}
> {"execute":"balloon","arguments":{"value":3000000000}}
> {"return": {}}
> {"execute":"query-balloon"}
> {"return": {"actual": 4288675840, "mem_swapped_in": 0, "minor_page_faults": 0,
> "mem_swapped_out": 0, "free_mem": 3603152896, "major_page_faults": 0,
> "total_mem": 4294545408}}
> 
> virtio-win-1.1.7-1:
> {"execute":"query-balloon"}
> {"return": {"actual": 4294967296, "mem_swapped_in": 1959}}
> {"execute":"balloon","arguments":{"value":3000000000}}
> {"return": {}}
> {"execute":"query-balloon"}
> {"return": {"actual": 4282384384, "mem_swapped_in": 0}}
> {"execute":"query-balloon"}
> {"return": {"actual": 4280287232, "mem_swapped_in": 0}}    

Hi,Vadim
We can see the above two balloon drivers display info very different, info become shorter for virtio-win-1.1.7-1.
So is it by design or else?
Thanks,
Shirley

Hi Shirley,
It must be the same. I will recheck it soon.
Regards,
Vadim.

For your info:

evict memory does not work on windows xp guest with driver virtio-win-1.1.8-0.

some additional info:
Memory reduce 2M on each query balloon, as following steps:

1.run win08 r2 guest, and install virtio balloon, install balloon service and reboot guest
/usr/libexec/qemu-kvm  -M rhel6.0.0 -enable-kvm -m 4096 ....  -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
2.query balloon info
{"execute":"query-balloon"}
{"return": {"actual": 4294967296, "mem_swapped_in": 0}}
3.do evict memory 
{"execute":"balloon","arguments":{"value":2097152000}}
{"return": {}} 
4.query balloon info for 5 times
{"execute":"query-balloon"}
{"return": {"actual": 4286578688, "mem_swapped_in": 0}}
{"execute":"query-balloon"}
{"return": {"actual": 4284481536, "mem_swapped_in": 0}}
{"execute":"query-balloon"}
{"return": {"actual": 4282384384, "mem_swapped_in": 0}}
{"execute":"query-balloon"}
{"return": {"actual": 4280287232, "mem_swapped_in": 0}}
{"execute":"query-balloon"}
{"return": {"actual": 4278190080, "mem_swapped_in": 0}}
We can see memory reduce 2M on each query.
5. after 5 mins,query balloon info again
{"execute":"query-balloon"}
{"return": {"actual": 4276092928, "mem_swapped_in": 0}}
Memory reduce 2M again.
And we can see Available memory in guest change according to each query.

I run this win08r2 guest using virt-manager, install virtio balloon driver, install balloon service, and reboot guest, and then do memory evict using virsh, and I can see memory become value we set in about 10 secs.

Please refer to libvirt log for detail info.

Created attachment 433098 [details]
libvirt log

Virtio ballooning does not work at all on qemu-kvm-0.12.1.2-2.113.el6 as following:

(qemu) info balloon 
balloon: actual=4096
(qemu) balloon 2048 // do evict memory
(qemu) info balloon 
balloon: actual=4092
(qemu) info balloon 
balloon: actual=4092
(qemu) info balloon 
balloon: actual=4092
(qemu) info balloon 
balloon: actual=4092
(qemu) info balloon 
balloon: actual=4092 

This is no memory change during each query.

Please check with the latest drivers from 
http://download.lab.bos.redhat.com/devel/RHEV/virtio-win/1.1.14-0/

Test this bug with driver in comment 18 as following steps:

1.start win2008 x64 guest with balloon option
2.install virtio balloon driver
3.reboot guest
4.install balloon server
5.do memory evict

(qemu) info balloon 
balloon: actual=4096
(qemu) balloon 2048
(qemu) info balloon 
balloon: actual=4040
(qemu) info balloon 
balloon: actual=4036
(qemu) info balloon 
balloon: actual=4036
(qemu) info balloon 
balloon: actual=4036

from above message, balloon does not work. so reassign this bug.

Please check with the latest drivers from 
http://download.lab.bos.redhat.com/devel/RHEV/virtio-win/1.1.15/

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0782.html