Description of problem:

When a VM contains a device like

  <hostdev managed="no" mode="subsystem" rawio="yes" type="scsi">
    <source>
      <adapter name="scsi_host16"/>
      <address bus="0" target="0" unit="4"/>
    </source>
    <alias name="ua-a03481b3-d43c-4fa1-9566-640e092f384e"/>
  </hostdev>

in its domain XML, it fails to start with the following error message from libvirt:

  error : qemuBlockNodeNameValidate:46 : internal error: node-name 'libvirt-ua-a03481b3-d43c-4fa1-9566-640e092f384e-backend' too long for qemu

Version-Release number of selected component (if applicable):

6.6.0-4.module+el8.3.0+7883+3d717aa8

How reproducible:

100%

Steps to Reproduce:
1. Start a VM with a SCSI hostdev similar to the one above.

Actual results:

VM fails to start.

Expected results:

VM starts.

Additional info:

See Bug 1876605 for logs and more info if needed.

It looks related to libvirt commit 245ed36e9764906f6164ba20e4531fa0b1c4dd3c. libvirt documentation doesn't state any limits on user alias length. The alias is used to make a storage node name, which is later rejected because it exceeds the 32 characters limit.