From 27687d256f31f38b13c38cebf7fc84aadd8c70dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Tue, 19 Feb 2013 21:08:41 +0000
Subject: [PATCH] AssigningDevices changed

Finding USB controller for given USB device
---
 AssigningDevices.md | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/AssigningDevices.md b/AssigningDevices.md
index b33f48c2..3f2f163a 100644
--- a/AssigningDevices.md
+++ b/AssigningDevices.md
@@ -31,6 +31,39 @@ TODO
 
 \<screenshot\>
 
+Finding right USB controller
+----------------------------
+
+If you want assign certain USB device to VM (by attaching whole USB controller), you need to figure out which PCI device is the right controller. First check to which USB bus device is connected:
+
+``` {.wiki}
+lsusb
+```
+
+For example I want assign broadband modem to netvm. In lsusb output it can be something like (in this case device isn't fully identified):
+
+``` {.wiki}
+Bus 003 Device 003: ID 413c:818d Dell Computer Corp.
+```
+
+The device is connected to USB bus 3. Then check which other devices are connected to the same bus - all of them will be assigned to the same VM. Now is the time to find right USB controller:
+
+``` {.wiki}
+readlink /sys/bus/usb/devices/usb3
+```
+
+This should output something like:
+
+``` {.wiki}
+../../../devices/pci-0/pci0000:00/0000:00:1a.0/usb3
+```
+
+Now you see BDF address in the path (right before final usb3). Strip leading "0000:" and pass the rest to qvm-pci tool:
+
+``` {.wiki}
+qvm-pci -a netvm 00:1a.0
+```
+
 Possible issues
 ---------------