From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [RFC PATCH v2 19/20] x86: Access the setup data through debugfs un-encrypted Date: Fri, 16 Sep 2016 09:11:47 +0200 Message-ID: <20160916071147.GB23229@nazgul.tnic> References: <20160822223529.29880.50884.stgit@tlendack-t1.amdoffice.net> <20160822223859.29880.60652.stgit@tlendack-t1.amdoffice.net> <20160912165944.rpqbwxz2biathnt3@pd.tnic> <4a357b9b-7d53-5bd6-81db-9d8cc63a6c72@amd.com> <20160914145101.GB9295@nazgul.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Tom Lendacky Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Radim =?utf-8?B?S3LEjW3DocWZ?= , Matt Fleming , x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Alexander Potapenko , "H. Peter Anvin" , linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jonathan Corbet , linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Ingo Molnar , Andrey Ryabinin , Arnd Bergmann , Andy Lutomirski , Thomas Gleixner , Dmitry Vyukov , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Paolo Bonzini List-Id: linux-mm.kvack.org On Thu, Sep 15, 2016 at 12:08:04PM -0500, Tom Lendacky wrote: > The problem is that this physical address does not contain the > encryption bit, and even if it did, it wouldn't matter. The __va() > define creates a virtual address that will be mapped as encrypted given > the current approach (which is how I found this). It's only ioremap() > that would create a mapping without the encryption attribute and since > this is unencrypted data it needs to be access accordingly. I see. So since this is not obvious, please add this explanation to maybe Documentation/x86/amd-memory-encryption.txt and point in there to an example or so so. Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --