From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: Re: [RFC PATCH v2 05/32] x86: Use encrypted access of BOOT related data with SEV Date: Thu, 16 Mar 2017 14:03:58 -0500 Message-ID: <8715da04-2d25-d1f2-3082-f45750c4f2d9@amd.com> References: <148846752022.2349.13667498174822419498.stgit@brijesh-build-machine> <148846757895.2349.561582698953591240.stgit@brijesh-build-machine> <20170307110925.zmo7gsflxhui4k7e@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170307110925.zmo7gsflxhui4k7e@pd.tnic> Sender: owner-linux-mm@kvack.org To: Borislav Petkov , Brijesh Singh Cc: simon.guinot@sequanux.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, rkrcmar@redhat.com, matt@codeblueprint.co.uk, linux-pci@vger.kernel.org, linus.walleij@linaro.org, gary.hook@amd.com, linux-mm@kvack.org, paul.gortmaker@windriver.com, hpa@zytor.com, cl@linux.com, dan.j.williams@intel.com, aarcange@redhat.com, sfr@canb.auug.org.au, andriy.shevchenko@linux.intel.com, herbert@gondor.apana.org.au, bhe@redhat.com, xemul@parallels.com, joro@8bytes.org, x86@kernel.org, peterz@infradead.org, piotr.luc@intel.com, mingo@redhat.com, msalter@redhat.com, ross.zwisler@linux.intel.com, dyoung@redhat.com, jroedel@suse.de, keescook@chromium.org, arnd@arndb.de, toshi.kani@hpe.com, mathieu.desnoyers@efficios.com, luto@kernel.org, devel@linuxdriverproject.org, bhelgaas@google.com, tglx@linutronix.de, mchehab@ke List-Id: linux-efi@vger.kernel.org On 3/7/2017 5:09 AM, Borislav Petkov wrote: > On Thu, Mar 02, 2017 at 10:12:59AM -0500, Brijesh Singh wrote: >> From: Tom Lendacky >> >> When Secure Encrypted Virtualization (SEV) is active, BOOT data (such as >> EFI related data, setup data) is encrypted and needs to be accessed as >> such when mapped. Update the architecture override in early_memremap to >> keep the encryption attribute when mapping this data. > > This could also explain why persistent memory needs to be accessed > decrypted with SEV. I'll add some comments about why persistent memory needs to be accessed decrypted (because the encryption key changes across reboots) for both SME and SEV. > > In general, what the difference in that aspect is in respect to SME. And > I'd write that in the comment over the function. And not say "E820 areas > are checked in making this determination." because that is visible but > say *why* we need to check those ranges and determine access depending > on their type. Will do. Thanks, Tom > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org