Re: [PATCH v11 09/13] x86, sgx: basic routines for enclave page cache

[Jarkko Sakkinen]

On Tue, 2018-06-19 at 08:32 -0700, Dave Hansen wrote:
> > For 32-bit (albeit not supported at this point) it makes sense to always
> > use kmap_atomic_pfn() as the virtua address area is very limited.
> 
> That makes no sense.  32-bit kernels have plenty of virtual address
> space if not using highmem.

AFAIK the vmalloc area is located in the last 128MB that and ioremap()
of EPC would consume a big portion of that.

> > KVM works only with writable MSRs. Driver works both with writable
> > and read-only MSRs.
> 
> Could you help with my confusion by documenting this a bit?

Sure.

/Jarkko