high cpu usage while pci passthrough nic

yuguang

New Member
Aug 7, 2019
3
0
1
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run iperf3 test on host system the cpu usage only 5%, but passthrough the same nic to vm system ,run same iperf3 test cpu usage about 25%~30% (for 4 cores, about 90% for single core).
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host system proxmox ve 5.4 kernel 4.15; vm system ubuntu 18.04 kernel 4.15.

HTML:
  /usr/bin/kvm -id 300 -name ubuntu18.04 -chardev socket,id=qmp,path=/var/run/qemu-server/300.qmp,server,nowait -mon chardev=qmp,mode=control -chardev socket,id=qmp-event,path=/var/run/qmeventd.sock,reconnect=5 -mon chardev=qmp-event,mode=control -pidfile /var/run/qemu-server/300.pid -daemonize -smbios type=1,uuid=8db17127-bbf1-4a1d-bc55-fe645ed77828 -drive if=pflash,unit=0,format=raw,readonly,file=/usr/share/pve-edk2-firmware//OVMF_CODE.fd -drive if=pflash,unit=1,format=raw,id=drive-efidisk0,file=/dev/pve/vm-300-disk-1 -smp 4,sockets=1,cores=4,maxcpus=4 -nodefaults -boot menu=on,strict=on,reboot-timeout=1000,splash=/usr/share/qemu-server/bootsplash.jpg -vnc unix:/var/run/qemu-server/300.vnc,x509,password -cpu host,+kvm_pv_unhalt,+kvm_pv_eoi -m 1024 -device vmgenid,guid=103bf74f-6a02-4428-b499-c140f8711fa2 -readconfig /usr/share/qemu-server/pve-q35.cfg -device usb-tablet,id=tablet,bus=ehci.0,port=1 -device vfio-pci,host=04:00.0,id=hostpci0,bus=ich9-pcie-port-1,addr=0x0 -device VGA,id=vga,bus=pcie.0,addr=0x1 -chardev socket,path=/var/run/qemu-server/300.qga,server,nowait,id=qga0 -device virtio-serial,id=qga0,bus=pci.0,addr=0x8 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -iscsi initiator-name=iqn.1993-08.org.debian:01:7a9b3c96e77 -drive if=none,id=drive-ide2,media=cdrom,aio=threads -device ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=200 -device virtio-scsi-pci,id=scsihw0,bus=pci.0,addr=0x5 -drive file=/dev/pve/vm-300-disk-0,if=none,id=drive-scsi0,format=raw,cache=none,aio=native,detect-zeroes=on -device scsi-hd,bus=scsihw0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0,id=scsi0,bootindex=100 -machine type=q35
 
Last edited:
host system proxmox ve 5.4 kernel 4.15; vm system ubuntu 18.04 kernel 4.15.
Upgrade to Proxmox VE 6.x to get the latest packages and Kernel. This may already improve things.
 

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