On Tue, May 24, 2016 at 09:54:31AM -0500, Tom Lendacky wrote: > On 05/12/2016 01:20 PM, Tom Lendacky wrote: > > On 05/10/2016 08:57 AM, Borislav Petkov wrote: > >> On Tue, May 10, 2016 at 02:43:58PM +0100, Matt Fleming wrote: > >>> Is it not possible to maintain some kind of kernel virtual address > >>> mapping so memremap*() and friends can figure out when to twiddle the > >>> mapping attributes and map with/without encryption? > >> > >> I guess we can move the sme_* specific stuff one indirection layer > >> below, i.e., in the *memremap() routines so that callers don't have to > >> care... That should keep the churn down... > >> > > > > We could do that, but we'll have to generate that list of addresses so > > that it can be checked against the range being mapped. Since this is > > part of early memmap support searching that list every time might not be > > too bad. I'll have to look into that and see what that looks like. > > I looked into this and this would be a large change also to parse tables > and build lists. It occurred to me that this could all be taken care of > if the early_memremap calls were changed to early_ioremap calls. Looking > in the git log I see that they were originally early_ioremap calls but > were changed to early_memremap calls with this commit: > > commit abc93f8eb6e4 ("efi: Use early_mem*() instead of early_io*()") > > Looking at the early_memremap code and the early_ioremap code they both > call __early_ioremap so I don't see how this change makes any > difference (especially since FIXMAP_PAGE_NORMAL and FIXMAP_PAGE_IO are > identical in this case). > > Is it safe to change these back to early_ioremap calls (at least on > x86)?
Commit f955371ca9d3986bca100666041fcfa9b6d21962 (x86: remove the Xen-specific _PAGE_IOMAP PTE flag) made commit abc93f8eb6e4 unnecessary. Though, IMO, it is still valid code cleanup. So, if it is not very strongly needed I would not revert this change. Daniel _______________________________________________ iommu mailing list firstname.lastname@example.org https://lists.linuxfoundation.org/mailman/listinfo/iommu