Will, > Given that the pool is relatively small (i.e. when compared with our virtual > address space), dedicating an area of virtual space sounds like it makes > the most sense here. How early do you need it to be available? How do we assign struct pages to a fixed virtual space area (I'm currently experimenting with 0xffff7f0000000000-0xffff7f0000200000)? Looks like filling page table entries (similarly to what's being done in arch/arm64/mm/kasan_init.c) is not enough. I thought maybe vmemmap_populate() would do the job, but it didn't (virt_to_pfn() still returns invalid PFNs).