Release of libvirt-7.5.0

The 7.5.0 release of both libvirt and libvirt-python is tagged and signed tarballs and source RPMs are available at https://libvirt.org/sources/ https://libvirt.org/sources/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing any other feedback. Your work is greatly appreciated. * Security * svirt: fix MCS label generation (CVE-2021-3631) A flaw in the way MCS labels were generated could result in a VM's resource not being fully protected from access by another VM were it to be compromised. https://gitlab.com/libvirt/libvirt/-/issues/153 * Removed features * xen: Remove support for Xen < 4.9 In accordance with our platform support policy, the oldest supported Xen version is now bumped from 4.6 to 4.9. * Improvements * docs: Document disk serial truncation status quo Disk ``<serial>`` is being truncated by QEMU before passed to the guest. Since it's impossible to fix it without running into further regressions the documentation was improved to document the intricacies. * Bug fixes * qemu: Fixed validation of disk ``iothread`` configuration The validation of ``iothread`` config was previously moved to a place where it caused bogus errors when address wasn't allocated when hotplugging a disk. The check is now removed as it wasn't actually necessary at all. Enjoy. Jirka