Nested-virtualization esxi under pve 5.0

[amdxp]

as captioned, i bulid a pve 5.0 system and successfully installed esxi 6.5 inside as a HOST of PVE,

Then, i can find some tutorial about enable hardware-assisted virtualization for ESXI 6.5 HOST.
seems fine to me...

Then i wonder to use esxi pci passthrough in esxi but they are all grey (not selectable). before that i do ensure i have enable vt-d in bios and it can work with my pve.

So, Please help if you know the answer and if possible to enable vt-d for HOST esxi 6.5 insdie PVE 5.0 for assigning HDD inside esxi 6.5,

Thanks for answering indeed.