VMD is weird, but at least it doesn't require big intrusive changes like decoupling your NVMe driver from PCIe. It's more like a weird special PCI-PCI bridge. Only needs a little extra driver: https://reviews.freebsd.org/D21383
VMD isn't the only method Intel has used to mess with how NVMe works. Their consumer chipsets going back at least to Kaby Lake had an even weirder "feature" that hid NVMe devices from PCIe enumeration and made them only accessible through proprietary interfaces on the chipset's SATA controller. Intel had to start using VMD on consumer platforms instead when AMD forced them to start providing more PCIe lanes from the CPU.
