RFE - Add support for QEMU's 9pfs's fmode/dmode options

Hello All, I recently ran into problems with the default very restrictive permissions for files that are created via 9pfs host/guest shares (600 for files, 700 for directories). QEMU added two new-ish flags, fmode and dmode, to its 9pfs implementation so that users are able to control these exact permissions. Would it be possible to expose these two flags via the domain XML? I made an issue on the libvirt Gitlab ( https://gitlab.com/libvirt/libvirt/-/issues/80) but it appears mailing list posts may be preferred. Thank you