danpb has mentioned that Linux gets this information from SCSI INQUIRY response. So it's up to the USB Mass Storage Device to decide whether or not it wants to have a removable medium.
The SCSI INQUIRY RMB (removable medium bit) tends to be set on modern USB Mass Storage Devices. Of course they don't actually have a removable medium. One side-effect of setting this bit is that Windows Auto-Run will work if RMB=0 but not work if RMB=0. Also, on RMB=1 devices only the first partition is displayed by Windows - you can't have more than one partition on the device. For more information, see: http://www.microsoft.com/whdc/connect/usb/usbfaq.mspx So at the end of the day, it's up to QEMU whether or not to mark USB MSDs as having removable media. Since modern devices tend to set RMB=1, we probably should too. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/686613 Title: USB MSD are not marked as removable Status in QEMU: Confirmed Bug description: Filed from Fedora bug: https://bugzilla.redhat.com/show_bug.cgi?id=589130 Guests can access USB Mass Storage Device, but fail to mark them as removable.