I am also having problems with using real USB devices. I tried a C-Media USB sound card, a CISCO USB headset, and a PNY flash drive. All of them seem to be detected by the Windows 7 guest, but can't be started for some reason. I have tried running as root. I didn't see any libusb errors. My Windows 2000 guest also has issues with starting the USB sound card.
My command-line: sudo qemu-system-x86_64 -hda "Windows 7 HD.qcow2" -boot "c" -m 5000 -device ich9-usb-ehci1 -device usb-host,vendorid=0x0930,productid=0x6545 Even when I unmount the flash drive first Mac OS 11.1 will actually mount the flash drive when I try using it in QEMU. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1850570 Title: Cannot use usb-host on Mac OS Status in QEMU: New Bug description: Usb-host will not work on Mac OS 10.15. Qemu runs, though it gives these errors and the drive does not show up. Also, when Qemu is starting the drive ejects and remounts twice. Qemu built with ./configure --target-list=i386-softmmu,x86_64-softmmu --enable-sdl --disable-cocoa --enable-sdl-image. qemu-system-i386 image.qcow -usb -device usb-kbd -device usb-host,vendorid=0x0781,productid=0x5571 libusb: error [darwin_claim_interface] USBInterfaceOpen: another process has device opened for exclusive access libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] USBInterfaceOpen: another process has device opened for exclusive access libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found libusb: error [darwin_claim_interface] interface not found To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1850570/+subscriptions
