Comment 17 for bug 1847361

Yeah, the workaround can be a disk that "fails" which helps to be not guest detectable:

Check libs before the workaround:
$ sudo lsof -p 9952 | awk '{print $9}' | grep '\.so' | sort | uniq > pre.libs

Then attach a XML that is valid for libvirt, but will fail to attach a disk (after loading the .so files)
  <disk type='network' device='disk'>
    <driver name='qemu' type='raw'/>
    <source protocol="http" name="does-not-exist">
            <host name="localhost" port="80"/>
    </source>
    <target dev='vdc' bus='virtio'/>
    <readonly/>
  </disk>

You'll get a fail (intentionally) like:
$ virsh attach-device guest1 non-disk.xml
error: Failed to attach device from on-disk.xml
error: internal error: unable to execute QEMU command 'device_add': Property 'virtio-blk-device.drive' can't find value 'drive-virtio-disk2'

Check after this:
$ sudo lsof -p 9952 | awk '{print $9}' | grep '\.so' | sort | uniq > post.libs

And we see all of them loaded:
$ diff -Naur pre.libs post.libs | grep '^+'
+++ post.libs 2019-11-18 07:01:55.461495910 +0100
+/lib/x86_64-linux-gnu/libcom_err.so.2.1
+/lib/x86_64-linux-gnu/libcrypt-2.27.so
+/lib/x86_64-linux-gnu/libkeyutils.so.1.5
+/usr/lib/x86_64-linux-gnu/libasn1.so.8.0.0
+/usr/lib/x86_64-linux-gnu/libcurl-gnutls.so.4.5.0
+/usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2.2
+/usr/lib/x86_64-linux-gnu/libgssapi.so.3.0.0
+/usr/lib/x86_64-linux-gnu/libhcrypto.so.4.1.0
+/usr/lib/x86_64-linux-gnu/libheimbase.so.1.0.0
+/usr/lib/x86_64-linux-gnu/libheimntlm.so.0.1.0
+/usr/lib/x86_64-linux-gnu/libhx509.so.5.0.0
+/usr/lib/x86_64-linux-gnu/libk5crypto.so.3.1
+/usr/lib/x86_64-linux-gnu/libkrb5.so.26.0.0
+/usr/lib/x86_64-linux-gnu/libkrb5.so.3.3
+/usr/lib/x86_64-linux-gnu/libkrb5support.so.0.1
+/usr/lib/x86_64-linux-gnu/liblber-2.4.so.2.10.8
+/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.10.8
+/usr/lib/x86_64-linux-gnu/libnghttp2.so.14.15.2
+/usr/lib/x86_64-linux-gnu/libpsl.so.5.2.0
+/usr/lib/x86_64-linux-gnu/libroken.so.18.1.0
+/usr/lib/x86_64-linux-gnu/librtmp.so.1
+/usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6
+/usr/lib/x86_64-linux-gnu/libwind.so.0.0.0
+/usr/lib/x86_64-linux-gnu/qemu/block-curl.so