[Qemu-devel] [PATCH 0/4] usb: hotplug support for usb-bot and usb-uas

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

Composite device hotplug is a long-standing issue in qemu.

PCI multifunction hotplug has been solved recently in a pci-specific
way, by simply not showing hot-plugged functions to the guest until
function #0 is plugged.

So I figured we maybe should check whenever we can apply a simliar trick
to USB composite devices.  As the usb subsystem already can hide usb
devices from the guest (used for example with usb-host, in case the
physical usb device is not plugged in the host machine) this turned out
to be surprisingly simple.

So, here we go.  Basic idea is the "attached" state becomes settable via
monitor.  Now you can create a usb-bot (or usb-uas) device, then attach
the scsi device(s) you want, and when you are done you flip attached to
true to make the composed device visible to the guest.

pleae review & comment,
  Gerd

Gerd Hoffmann (4):
  usb: make USBDevice->attached bool
  usb: add attached property
  usb-bot: hotplug support
  usb-uas: hotplug support

 hw/usb/bus.c         | 50 ++++++++++++++++++++++++++++++++++++++++++++++----
 hw/usb/dev-storage.c |  8 ++++++--
 hw/usb/dev-uas.c     |  5 +++++
 include/hw/usb.h     |  3 ++-
 4 files changed, 59 insertions(+), 7 deletions(-)

-- 
1.8.3.1