usbFindDevice():get usb device according to
idVendor, idProduct, bus, device
it is the exact match of the four parameters
usbFindDeviceByBus():get usb device according to bus, device
it returns only one usb device same as usbFindDevice
usbFindDeviceByVendor():get usb device according to idVendor,idProduct
it probably returns multiple usb devices.
usbDeviceSearch(): a helper function to do the actual search
Fedora bug https://bugzilla.redhat.com/show_bug.cgi?id=598272
Some files under /sys/bus/usb/devices/ have the format 'usbX', where
X is the USB bus number. Use STRPREFIX to correctly parse the bus numbers.
Changeset
commit 5073aa994a
Author: Cole Robinson <crobinso@redhat.com>
Date: Mon Jan 11 11:40:46 2010 -0500
Added support for product/vendor based passthrough, but it only
worked at the security driver layer. The main guest XML config
was not updated with the resolved bus/device ID. When the QEMU
argv refactoring removed use of product/vendor, this then broke
launching guests.
THe solution is to move the product/vendor resolution up a layer
into the QEMU driver. So the first thing QEMU does is resolve
the product/vendor to a bus/device and updates the XML config
with this info. The rest of the code, including security drivers
and QEMU argv generated can now rely on bus/device always being
set.
* src/util/hostusb.c, src/util/hostusb.h: Split vendor/product
resolution code out of usbGetDevice and into usbFindDevice.
Add accessors for bus/device ID
* src/security/virt-aa-helper.c, src/security/security_selinux.c,
src/qemu/qemu_security_dac.c: Remove vendor/product from the
usbGetDevice() calls
* src/qemu/qemu_driver.c: Use usbFindDevice to resolve vendor/product
into a bus/device ID
All callers now pass a NULL virConnectPtr into the USB/PCi device
iterator functions. Therefore the virConnectPtr arg can now be
removed from these functions
* src/util/hostusb.h, src/util/hostusb.c: Remove virConnectPtr
from usbDeviceFileIterate
* src/util/pci.c, src/util/pci.h: Remove virConnectPtr arg from
pciDeviceFileIterate
* src/qemu/qemu_security_dac.c, src/security/security_selinux.c: Update
to drop redundant virConnectPtr arg
Based off how QEMU does it, look through /sys/bus/usb/devices/* for
matching vendor:product info, and if found, use info from the surrounding
files to build the device's /dev/bus/usb path.
This fixes USB device assignment by vendor:product when running qemu
as non-root (well, it should, but for some reason I couldn't reproduce
the failure people are seeing in [1], but it appears to work properly)
[1] https://bugzilla.redhat.com/show_bug.cgi?id=542450
