I tested this again on the latest Qemu and Linux kernel and cannot reproduce it anymore, so this can be closed now..
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1792523 Title: usb passthrough not resetting on host after vm shutdown if started with -daemonize Status in QEMU: New Bug description: Below is the full Qemu command used to launch the VM. Have been using this same setup since Qemu 2.12, plus a couple of cherry picked patch commits fixing ide-hd and e1000e in Windows guests. Both sets of patches have now been merged to 3.0, so decided to update to 3.0. The VM launches and runs fine, but after shutting down, the usb devices that are passed through from the host (keyboard, mouse) do not work until unplugged and plugged in again. Have narrowed this down to the -daemonize -pidfile arguments.. if those lines are removed, usb devices work in the host again right away after VM shutdown. CPU: Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz OS: Linux dev 4.18.6-arch1-1-ARCH #1 SMP PREEMPT Wed Sep 5 11:54:09 UTC 2018 x86_64 GNU/Linux Thank you for looking into this! #!/usr/bin/env bash echo vfio-pci > /sys/bus/pci/devices/0000:04:00.0/driver_override echo 0000:04:00.0 > /sys/bus/pci/devices/0000:04:00.0/driver/unbind echo 0000:04:00.0 > /sys/bus/pci/drivers/vfio-pci/bind echo > /sys/bus/pci/devices/0000:04:00.0/driver_override /usr/bin/qemu-system-x86_64 \ -name winnt \ -daemonize \ -pidfile /run/vms/qemu/winnt.pid \ -boot menu=on \ -drive if=pflash,format=raw,readonly,file=/opt/vms/qemu/machines/ovmf_code_patched.fd \ -drive if=pflash,format=raw,file=/opt/vms/qemu/machines/winnt/ovmf_vars_patched.fd \ -machine pc-q35-3.0,accel=kvm \ -nodefaults \ -cpu host,kvm=off,hv_vendor_id=RedHat,hv_time,hv_relaxed,hv_vapic,hv_spinlocks=0x1fff \ -accel kvm \ -smp 4,sockets=1,cores=4,threads=1 \ -m 16G \ -nic bridge,br=br0,mac=52:54:00:12:34:77,model=e1000e \ -device vfio-pci,host=01:00.0,multifunction=on \ -device vfio-pci,host=01:00.1 \ -vga none \ -display none \ -monitor none \ -blockdev raw,node-name=ide-hd.0,cache.direct=on,discard=unmap,file.driver=host_device,file.aio=native,file.filename=/dev/disk/by-id/ata-WDC_WDS500G2B0A-00SM50_181265803048 \ -device ide-hd,drive=ide-hd.0,bus=ide.0,rotation_rate=1 \ -blockdev raw,node-name=ide-hd.1,cache.direct=on,file.driver=host_device,file.aio=native,file.filename=/dev/disk/by-id/ata-TOSHIBA_HDWE160_X746K8ZTF56D-part1 \ -device ide-hd,drive=ide-hd.1,bus=ide.1 \ -device vfio-pci,host=04:00.0 \ -device qemu-xhci \ -device usb-host,vendorid=0x04d9,productid=0x0171 \ -device usb-host,vendorid=0x1532,productid=0x005c \ -device usb-host,vendorid=0x1b1c,productid=0x0c09 echo 0000:04:00.0 > /sys/bus/pci/devices/0000:04:00.0/driver/unbind echo 0000:04:00.0 > /sys/bus/pci/drivers_probe To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1792523/+subscriptions