Add some notes for myself

notes-for-self.md

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+### USB passthrough notes
+
+#### USB 3.0 flash drive
+
+The following USB configuration works for usb passthrough of a USB 3.0 flash
+drive to Fedora 25 guest.
+
+    -device nec-usb-xhci,id=xhci \
+    -device usb-host,bus=xhci.0,vendorid=0x0781,productid=0x5590 \
+    -usb -device usb-mouse,bus=usb-bus.0 -device usb-kbd,bus=usb-bus.0 \
+    ...
+
+#### Moto G3 phone
+
+The following USB configuration works for usb passthrough of a Moto G3 phone to
+Fedora 25 guest.
+
+    -device usb-host,bus=usb-bus.0,vendorid=0x22b8,productid=0x002e \
+    -usb -device usb-mouse,bus=usb-bus.0 -device usb-kbd,bus=usb-bus.0 \
+    ...
+
+#### CoolerMaster keyboard
+
+The following USB configuration works for usb passthrough of a CoolerMaster
+keyboard to macOS Sierra guest!
+
+    -device usb-host,bus=usb-bus.0,vendorid=0x2516,productid=0x0004 \
+    -usb -device usb-tablet,bus=usb-bus.0 -device usb-kbd,bus=usb-bus.0 \
+    ...
+
+
+#### Virtual USB disk
+
+The following USB configuration works for attaching a virtual USB disk to macOS
+Sierra guest. Use "qemu-img" to create "disk.raw" virtual disk.
+
+    -drive if=none,id=usbstick,file=disk.raw,format=raw \
+    -device usb-storage,bus=usb-bus.0,drive=usbstick \
+    ...
+
+However USB passthrough of EHCI, and XHCI (USB 3.0) devices does not work with
+macOS Sierra. See https://bugs.launchpad.net/qemu/+bug/1509336 for
+confirmation. According to this bug report, USB passthrough does not work with
+versions >= Mac OS X El Capitan guests.
+
+It seems that this problem can be fixed by using OVMF + Clover.
+
+Update: OVMF + Clover doesn't help. It seems that macOS is missing the required
+drivers for the EHCI, and XHCI controllers that are exposed by QEMU.