What were you trying to do that didn't work?

Libvirt needs to be able to query whether TDX is usable on a host. Currently QEMU only provides a way to query whether TDX is compiled in.

The original TDX patches for QEMU provided a "query-tdx-capabilities" which was an analogue of 'query-sev-capabilities', and libvirt should have used that to determine if TDX was usable on the host. That QMP command seems to have got lost somewhere along the way

https://mail.gnu.org/archive/html/qemu-devel/2021-07/msg01689.html

What is the impact of this issue to you?

Libvirt has no knowledge of whether TDX is actually usable by QEMU.

Libvirt will have to directly open /dev/kvm and query for the TDX VM type, which while possible, is not something libvirt should have todo directly.

Please provide the package NVR for which the bug is seen:

qemu-kvm-10.0.0-14.el10_1.x86_64