Redirecting USB device to a virtual machine with virt-manager does not work

Solution 1:

The solution for me was to create the /etc/udev/rules.d/50-spice.rules files, then to add <allow_any>yes</allow_any> under the <defaults> section in /usr/share/polkit-1/actions/org.spice-space.lowlevelusbaccess.policy. After modification, the file looks like this on my machine:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policyconfig PUBLIC
          "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
          "http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
<policyconfig>

  <vendor>The Spice Project</vendor>
  <vendor_url>http://spice-space.org/</vendor_url>
  <icon_name>spice</icon_name>

  <action id="org.spice-space.lowlevelusbaccess">
    <description>Low level USB device access</description>
    <message>Privileges are required for low level USB device access (for usb device pass through).</message>
    <defaults>
      <allow_any>yes</allow_any>
      <allow_inactive>no</allow_inactive>
      <allow_active>yes</allow_active>
    </defaults>
  </action>

</policyconfig>