Hello, i've 4 USB serial devices and one HID device i want to pass to a guest.
The passing itself works fine but while the guest has 0 load or cpu usage the qemu process itself has around 40% cpu usage on a single 3,2 ghz E3 xeon. I already tried xhci but it doesn't change anything. Also the latency of the usb devices is very high and fluctuate. Qemu Version 1.7.1 Inside the guest: # lsusb -t /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M |__ Port 1: Dev 2, If 0, Class=HID, Driver=usbhid, 480M |__ Port 2: Dev 3, If 0, Class=HID, Driver=usbfs, 12M |__ Port 3: Dev 4, If 0, Class=vend., Driver=ftdi_sio, 12M |__ Port 4: Dev 5, If 0, Class=hub, Driver=hub/8p, 12M |__ Port 1: Dev 6, If 0, Class=vend., Driver=ftdi_sio, 12M |__ Port 2: Dev 7, If 0, Class=comm., Driver=cdc_acm, 12M |__ Port 2: Dev 7, If 1, Class=data, Driver=cdc_acm, 12M |__ Port 3: Dev 8, If 0, Class=vend., Driver=ftdi_sio, 12M Qremu command line: qemu -pidfile /var/run/qemu-server/102.pid -daemonize -name test -smp sockets=1,cores=1 -nodefaults -boot menu=on,strict=on,reboot-timeout=1000 -vga cirrus -cpu kvm64,+lahf_lm,+x2apic,+sep -k de -m 1024 -device nec-usb-xhci,id=xhci,bus=pci.0,addr=0x1.0x2 -device usb-tablet,id=tablet,bus=xhci.0,port=1 -device usb-host,hostbus=2,hostport=1.2 -device usb-host,hostbus=2,hostport=1.3 -device usb-host,hostbus=2,hostport=1.4 -device usb-host,hostbus=2,hostport=1.1.1 -device usb-host,hostbus=2,hostport=1.1.4 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -device virtio-scsi-pci,id=scsihw0,bus=pci.0,addr=0x5 -drive file=/ssdstor/images/102/vm-102-disk-1.qcow2,if=none,id=drive-scsi0,format=qcow2,cache=writeback,discard=on,aio=native -device scsi-hd,bus=scsihw0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0,id=scsi0 -netdev type=tap,id=net0,ifname=tap102i0,script=/var/lib/qemu-server/pve-bridge,vhost=on -device virtio-net-pci,mac=3A:53:02:E3:76:59,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300 Does anybody have an idea how to lower the CPU usage? Greets, Stefan