Split off from https://bugs.launchpad.net/qemu/+bug/1579306 as this is a distinct issue.
Physical USB storage devices that support the UAS protocol do not work correctly when passed through to Windows guests (I've only tested this with Windows 10 x64, build 1607).
Passing through such a device results in the older BOT/MSC protocol being used:
<See attachment win10-uas-fail.png>
Using the same domain configuration with a Linux guest (tested with SystemRescueCD 4.8.0) works correctly:
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
|__ Port 1: Dev 2, If 0, Class=Mass Storage, Driver=uas, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M
In both cases, the VM was launched via libvirt, which generated the following command line:
/usr/bin/qemu-system-x86_64 -name guest=Win10-Edge-IE11,debug-threads=on -S -object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-13-Win10-Edge-IE11/master-key.aes -machine pc-q35-2.7,accel=kvm,usb=off,vmport=off,dump-guest-core=off -cpu host,hv_time,hv_relaxed,hv_vapic,hv_spinlocks=0x1fff -m 4096 -realtime mlock=off -smp 8,sockets=1,cores=4,threads=2 -uuid 47c39707-088c-4edc-8b6a-a7856e09f43d -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-13-Win10-Edge-IE11/monitor.sock,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=localtime,driftfix=slew -global kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -device i82801b11-bridge,id=pci.1,bus=pcie.0,addr=0x1e -device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x0 -device nec-usb-xhci,id=usb,bus=pci.2,addr=0x6 -device virtio-scsi-pci,id=scsi0,bus=pci.2,addr=0x3 -device virtio-serial-pci,id=virtio-serial0,bus=pci.2,addr=0x4 -drive file=/home/jack/IMG/Win10-Edge-IE11.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-0,discard=unmap -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1 -drive if=none,id=drive-scsi0-0-0-1,readonly=on -device scsi-cd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-0-1,id=scsi0-0-0-1 -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=24 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:27:94:5d,bus=pci.2,addr=0x1 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev spicevmc,id=charchannel0,name=vdagent -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0 -device usb-tablet,id=input0,bus=usb.0,port=2 -spice port=5900,addr=127.0.0.1,disable-ticketing,image-compression=off,seamless-migration=on -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pcie.0,addr=0x1 -device intel-hda,id=sound0,bus=pci.2,addr=0x2 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0,bus=usb.0,port=3 -chardev spicevmc,id=charredir1,name=usbredir -device usb-redir,chardev=charredir1,id=redir1,bus=usb.0,port=4 -device usb-host,hostbus=4,hostaddr=4,id=hostdev0,bus=usb.0,port=1 -device virtio-balloon-pci,id=balloon0,bus=pci.2,addr=0x5 -msg timestamp=on
The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting all older bugs to "Incomplete" now.
If you still think this bug report here is valid, then please switch the state back to "New" within the next 60 days, otherwise this report will be marked as "Expired". Thank you and sorry for the
inconvenience.