Thank you for your report. From the comments it has yet to be clarified whether there is a bug here, or missing support in libvirt/qemu for your particular requirements which might be considered a Wishlist feature request.
Either way this seems like "unusual end-user configurations or uncommon hardware" so I'm setting Importance to Low. Accordingly I wouldn't expect the Ubuntu Server Team to find the time to look into this soon, but feel free to use this bug to coordinate with others also affected.
Thank you for your report. From the comments it has yet to be clarified whether there is a bug here, or missing support in libvirt/qemu for your particular requirements which might be considered a Wishlist feature request.
Either way this seems like "unusual end-user configurations or uncommon hardware" so I'm setting Importance to Low. Accordingly I wouldn't expect the Ubuntu Server Team to find the time to look into this soon, but feel free to use this bug to coordinate with others also affected.