On Monday 11 Jan 2021 at 08:45:10 (-0600), Rob Herring wrote: > On Fri, Jan 8, 2021 at 6:16 AM Quentin Perret <qper...@google.com> wrote: > > > > Introduce early_init_dt_add_memory_hyp() to allow KVM to conserve a copy > > of the memory regions parsed from DT. This will be needed in the context > > of the protected nVHE feature of KVM/arm64 where the code running at EL2 > > will be cleanly separated from the host kernel during boot, and will > > need its own representation of memory. > > What happened to doing this with memblock?
I gave it a go, but as mentioned in v1, I ran into issues for nomap regions. I want the hypervisor to know about these memory regions (it's possible some of those will be given to protected guests for instance) but these seem to be entirely removed from the memblocks when using DT: https://elixir.bootlin.com/linux/latest/source/drivers/of/fdt.c#L1153 EFI appears to do things differently, though, as it 'just' uses memblock_mark_nomap() instead of actively removing the memblock. And that means I could actually use the memblock API for EFI, but I'd rather have a common solution. I tried to understand why things are done differently but couldn't find an answer and kept things simple and working for now. Is there a good reason for not using memblock_mark_nomap() with DT? If not, I'm happy to try that. Thanks, Quentin
