High host CPU for idle linux guest

[devilkin]

Hi,

I'm trying to figure out why one of my as good as idle guests (0-1% cpu) is using easily 8-10% of host cpu.

Config is fairly simple:

agent: 1
bios: ovmf
boot: c
bootdisk: scsi0
cores: 2
cpu: host
efidisk0: local-zfs:vm-103-disk-0,size=1M
ide2: local-zfs:vm-103-cloudinit,media=cdrom,size=4M
ipconfig0: ip=dhcp,ip6=dhcp
machine: q35
memory: 2048
net0: virtio=A2:25:39:F2:8A:50,bridge=vmbr0,firewall=1,tag=134
numa: 0
onboot: 1
ostype: l26
scsi0: local-zfs:vm-103-disk-1,size=32G,aio=native
scsihw: virtio-scsi-pci
smbios1: uuid=35d8c767-6c2a-4e23-926d-1dca3209e0fb
sockets: 1
startup: order=3
tablet: 0
vmgenid: 7cb21d39-1761-4262-854f-fbfb9e65e716

Running on an Intel(R) Xeon(R) CPU E3-1230 v5 @ 3.40GHz.

 

[oguz]

hi,

good as idle guests (0-1% cpu) is using easily 8-10% of host cpu.

where do you check the host cpu usage?

if you check htop on the host what do you see? or ps auxk '%cpu' (will show you the process list sorted by cpu use percentage)

 

[devilkin]

I was checking top, but also htop reports 2 threads, one at 0.7% and the other around 8% right now. The guest itself is a bare OS, nothing is running.