[PATCH 4/4] docs: add description for USB port matching

From: Maximilian Martin <maximilian_martin(a)gmx.de&gt; Adds documentation for the new USB bus/port addressing. The new "port" attribute is explained. Signed-off-by: Maximilian Martin <maximilian_martin(a)gmx.de&gt; --- docs/formatdomain.rst | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index c7c75ae219..3cc0bb0533 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -4784,19 +4784,22 @@ or: tweak the loading process further using the ``bar`` or ``file`` attributes will be rejected. :since:`Since 4.3.0 (QEMU and KVM only)`. ``address`` - The ``address`` element for USB devices has a ``bus`` and ``device`` - attribute to specify the USB bus and device number the device appears at on - the host. The values of these attributes can be given in decimal, hexadecimal - (starting with 0x) or octal (starting with 0) form. For PCI devices the - element carries 4 attributes allowing to designate the device as can be found - with the ``lspci`` or with ``virsh nodedev-list``. For SCSI devices a 'drive' - address type must be used. For mediated devices, which are software-only - devices defining an allocation of resources on the physical parent device, - the address type used must conform to the ``model`` attribute of element - ``hostdev``, e.g. any address type other than PCI for ``vfio-pci`` device API - or any address type other than CCW for ``vfio-ccw`` device API will result in - an error. See the `Device Addresses`_ section for more details on the address - element. + The ``address`` element for USB devices has a ``bus`` attribute to specify + the USB bus. In addition, either a ``device`` attribute or a ``port`` + attribute is required to identify the device on the host. While the device + number is assigned upon connection of the device, the port number is a + stable identifier of the physical host port. Bus and device number can be + given in decimal, hexadecimal (starting with 0x) or octal (starting with 0) + form. The port number is a dotted path (examples: ``2``, ``1.2.5``). For PCI + devices the element carries 4 attributes allowing to designate the device as + can be found with the ``lspci`` or with ``virsh nodedev-list``. For SCSI + devices a 'drive' address type must be used. For mediated devices, which are + software-only devices defining an allocation of resources on the physical + parent device, the address type used must conform to the ``model`` attribute + of element ``hostdev``, e.g. any address type other than PCI for ``vfio-pci`` + device API or any address type other than CCW for ``vfio-ccw`` device API + will result in an error. See the `Device Addresses`_ section for more details + on the address element. ``driver`` PCI hostdev devices can have an optional ``driver`` subelement that specifies which host driver to bind to the device when preparing it -- 2.39.5