Bug 1474452

Can you check that balloon service is up and running up on your system? 
If it is, then what is the balloon driver version?

Thanks,
Vadim.

Yes,if did not install blnsrv.exe in guest. The qmp output info will like that.
{ "execute": "qom-get","arguments": {"path":"/machine/peripheral/balloon0","property":"guest-stats" } }
{"return": {"stats": {"stat-swap-out": -1, "stat-available-memory": -1, "stat-free-memory": -1, "stat-minor-faults": -1, "stat-major-faults": -1, "stat-total-memory": -1, "stat-swap-in": -1}, "last-update": 1500963304}}

after run "blnsrv.exe -i" in windows guest. The qmp output info will be like:
{ "execute": "qom-get","arguments": {"path":"/machine/peripheral/balloon0","property":"guest-stats" } }
{"return": {"stats": {"stat-swap-out": 213032960, "stat-available-memory": 724871168, "stat-free-memory": 724869120, "stat-minor-faults": 1540819, "stat-major-faults": 21126, "stat-total-memory": 3220688896, "stat-swap-in": 611061760}, "last-update": 1500963581}}

Hello, Vadim,

The "Balloon" service is running:

"""
sc query "Balloon" | find "STATE"
        STATE               : 4 RUNNING
"""

Driver version is 61.74.104.14000 (this one should be from the last virtio-win iso 0.1.140.1-1, I also tried last stable 0.1.126 iso).

Yours sincerely,
Vadim

Hello, xiagao,

Thanks, that was the problem. Please, add this to your guides about installation of VirtIO drivers (as I have never found anything like that while searching the web).
For example on redhat customer portal:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/form-Virtualization_Host_Configuration_and_Guest_Installation_Guide-Para_virtualized_drivers-Mounting_the_image_with_virt_manager.html
I will suggest adding this info in ArchWiki if you don't mind.
Also marking issue as closed, not a bug.

Thanks,
Vadim

(In reply to Shiyanov Vadim from comment #4)
> Hello, xiagao,
> 
> Thanks, that was the problem. Please, add this to your guides about
> installation of VirtIO drivers (as I have never found anything like that
> while searching the web).
> For example on redhat customer portal:
> https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/
> html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/form-
> Virtualization_Host_Configuration_and_Guest_Installation_Guide-
> Para_virtualized_drivers-Mounting_the_image_with_virt_manager.html
> I will suggest adding this info in ArchWiki if you don't mind.
> Also marking issue as closed, not a bug.
> 
> Thanks,
> Vadim

Hi Vadim,

We will add it to the guide. And thanks for your testing and suggestion.

BR,
xiagao

thought I have install the virtio balloon driver ,and run the blnsrv.exe -i , but my win7 vm still can't get enough mem stat information,such as:

bash-4.1# virsh dommemstat root-vsys_win7
actual 2097152
last_update 1585044578
rss 36644

and the cmd:
bash-4.1# virsh qemu-monitor-command root-vsys_win7 '{"execute":"qom-get", "arguments":{"path":"//machine/peripheral/balloon0","property":"guest-stats"}}' --pretty
{
  "return": {
    "stats": {
      "stat-htlb-pgalloc": 18446744073709551615, //-1, 64bit
      "stat-swap-out": 18446744073709551615,    // -1, 64bit
      "stat-available-memory": 18446744073709551615,  // -1, 64bit
      "stat-htlb-pgfail": 18446744073709551615,
      "stat-free-memory": 18446744073709551615,
      "stat-minor-faults": 18446744073709551615,
      "stat-major-faults": 18446744073709551615,
      "stat-total-memory": 18446744073709551615,
      "stat-swap-in": 18446744073709551615,
      "stat-disk-caches": 18446744073709551615
    },
    "last-update": 1585044578
  },
  "id": "libvirt-952"
}
from above ,the qemu can't get guest root-vsys_win7 mem details

my virtio balloon driver is: 61.80.104.17300 and blnsrv status result :"Status: Service RUNNING"
my guest os is windows 7 64bit

can any one give me some suggestion ,what the reason lead the failure ? thanks !

(In reply to ks002278 from comment #6)
> thought I have install the virtio balloon driver ,and run the blnsrv.exe -i
> , but my win7 vm still can't get enough mem stat information,such as:
> 
> bash-4.1# virsh dommemstat root-vsys_win7
> actual 2097152
> last_update 1585044578
> rss 36644
> 
> and the cmd:
> bash-4.1# virsh qemu-monitor-command root-vsys_win7 '{"execute":"qom-get",
> "arguments":{"path":"//machine/peripheral/balloon0","property":"guest-
> stats"}}' --pretty
> {
>   "return": {
>     "stats": {
>       "stat-htlb-pgalloc": 18446744073709551615, //-1, 64bit
>       "stat-swap-out": 18446744073709551615,    // -1, 64bit
>       "stat-available-memory": 18446744073709551615,  // -1, 64bit
>       "stat-htlb-pgfail": 18446744073709551615,
>       "stat-free-memory": 18446744073709551615,
>       "stat-minor-faults": 18446744073709551615,
>       "stat-major-faults": 18446744073709551615,
>       "stat-total-memory": 18446744073709551615,
>       "stat-swap-in": 18446744073709551615,
>       "stat-disk-caches": 18446744073709551615
>     },
>     "last-update": 1585044578
>   },
>   "id": "libvirt-952"
> }
> from above ,the qemu can't get guest root-vsys_win7 mem details
> 
> my virtio balloon driver is: 61.80.104.17300 and blnsrv status result
> :"Status: Service RUNNING"
> my guest os is windows 7 64bit
> 
> can any one give me some suggestion ,what the reason lead the failure ?
> thanks !

Do you set "period" before getting memstat?
# virsh dommemstat win2016 --period 2
# virsh dommemstat win2016
actual 4194304
swap_in 1136256
swap_out 0
major_fault 61995
minor_fault 2628933
unused 3155332
available 4193760
usable 3176434
last_update 1637889879
disk_caches 42204
hugetlb_pgalloc 0
hugetlb_pgfail 0
rss 4305268

Thanks,
Xiaoling