From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masayoshi Mizuma Subject: Re: [PATCH v8 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory Date: Thu, 25 Oct 2018 09:40:51 -0400 Message-ID: <20181025134050.ggiir77ehntikbwg@gabell> References: <20181013203429.GE31650@zn.tnic> <20181013214550.ag5qzokhkrkwnzsy@gabell> <20181013220541.GI31650@zn.tnic> <20181015005035.z3xym6nx43hogdge@gabell> <20181016151353.punyk7exekut2543@gabell> <20181016191113.GI5212@zn.tnic> <20181016195429.tovdgqq77gz3eek2@gabell> <20181016195902.GK5212@zn.tnic> <20181022154204.kagmdb55jtoez4ca@gabell> <20181025103345.GF14020@nazgul.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20181025103345.GF14020@nazgul.tnic> Sender: linux-kernel-owner@vger.kernel.org To: Borislav Petkov Cc: Baoquan He , Ingo Molnar , Thomas Gleixner , Chao Fan , linux-kernel@vger.kernel.org, x86@kernel.org, linux-efi@vger.kernel.org, linux-acpi@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, keescook@chromium.org, rjw@rjwysocki.net, lenb@kernel.org, ard.biesheuvel@linaro.org, indou.takao@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com List-Id: linux-acpi@vger.kernel.org On Thu, Oct 25, 2018 at 12:33:45PM +0200, Borislav Petkov wrote: > On Mon, Oct 22, 2018 at 11:42:05AM -0400, Masayoshi Mizuma wrote: > > I'm trying to store the SRAT info and pass it to kernel_randomize_memory(), > > looks like add_e820ext()/parse_setup_data(). > > > > Is the approach useful only EFI environment? I'm not sure how I > > Does it matter for non-EFI even? > > I mean, you want this code only for your use case - when you have > movable memory and you're doing kexec, yes? > > And those machines are all EFI boxes I'd assume... My actual use case is for EFI boxes, however, I think it's better to useful for legacy BIOS as well because memory hot-plug affinity in SRAT and KASLR are available on legacy BIOS. Actually, we can create such environment in qemu. I have another idea to solve this issue. Adding a SRAT parsing code to arch/x86/mm/kaslr.c. It is useful for both EFI and BIOS and also we don't need a new kernel parameter... Dose the idea make sense? Thanks, Masa