Thanks, Daniel and Michal, for your review comments. I have incorporated
all comments and will submit a new patchset once Daniel's patch is
merged ("tests: validate an XML config with USB vendor/product set").
Am 26.06.2025 um 18:07 schrieb Daniel P. Berrangé via Devel:
On Thu, Jun 26, 2025 at 06:01:30PM +0200, Maximilian Martin wrote:
Am 23.06.2025 um 16:50 schrieb Daniel P. Berrangé:
On Mon, Apr 21, 2025 at 09:38:34PM +0200, Maximilian Martin via Devel wrote:
This resubmission splits up the previous patch into multiple patches and
incorporates review comments from Michal Prívozník.
Currently, only vendor/product and bus/device matching are supported for USB
host
devices. Neither of these provide a stable and persistent way of assigning a
guest
a specific host device. Vendor/product can be ambiguous. Device numbers change
on
every enumeration.
This patch adds a bus/port matching, which allows a specific port on the host
to be
specified using the dotted notation found in Linux's "devpath" sysfs attribute.
In terms of our API, we're expecting people to use the
'node device' APIs to identify what devices are available
on the host and their attributes, rather than queryin
Linux directly. This gives us a platform independant
usage model, which also works when the mgmt app has no
login to the virt host.
Currently for USB devices we report bus, dev, vendor & product,
but don't report the port:
# virsh nodedev-dumpxml usb_1_10_4
<device>
<name>usb_1_10_4</name>
<path>/sys/devices/pci0000:00/0000:00:14.0/usb1/1-10/1-10.4</path>
<devnode type='dev'>/dev/bus/usb/001/004</devnode>
<parent>usb_1_10</parent>
<driver>
<name>usb</name>
</driver>
<capability type='usb_device'>
<bus>1</bus>
<device>4</device>
<product id='0x10c0'>Dell Integrated Hub</product>
<vendor id='0x1604'>Tascam</vendor>
</capability>
</device>
we need to add 'port' to this xml document under the 'usb_device'
capability.
Well, the port is included in the path (everything after last '-'). udev
does not report it explicitly. Do you think this is enough or should I parse
the path and add the port to capabilites?
No, we would consider the path to be a platform specific opaque string,
and liable to change. So it isn't something apps should be parsing to
extract info from.
We need the path explicitly modelled under the usb_device capability
With regards,
Daniel
