On 06/13/2016 07:03 AM, Matt Fleming wrote:

On Thu, 09 Jun, at 11:16:40AM, Tom Lendacky wrote:

quoted

So maybe something along the lines of an enum that would have entries
(initially) like KERNEL_DATA (equal to zero) and EFI_DATA. Others could
be added later as needed.

 
Sure, that works for me, though maybe BOOT_DATA would be more
applicable considering the devicetree case too.

quoted

Would you then want to allow the protection attributes to be updated
by architecture specific code through something like a __weak function?
In the x86 case I can add this function as a non-SME specific function
that would initially just have the SME-related mask modification in it.

Would we need a new function? Couldn't we just have a new
FIXMAP_PAGE_* constant? e.g. would something like this work?

Looking forward to the virtualization support (SEV), the VM will be
completely encrypted from the time it is started. In this case all of
the UEFI data will be encrypted and I would need to insure that the
mapping reflects that. When I do the SEV patches, I can change the
FIXMAP #define to add some logic to return a value, so I think the
FIXMAP_PAGE_ idea can work.

Thanks,
Tom

---

enum memremap_owner {
	KERNEL_DATA = 0,
	BOOT_DATA,
};

void __init *
early_memremap(resource_size_t phys_addr, unsigned long size,
	       enum memremap_owner owner)
{
	pgprot_t prot;

	switch (owner) {
	case BOOT_DATA:
		prot = FIXMAP_PAGE_BOOT;
		break;
	case KERNEL_DATA:	/* FALLTHROUGH */
	default:
		prot = FIXMAP_PAGE_NORMAL;
		
	}

	return (__force void *)__early_ioremap(phys_addr, size, prot);
}