From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B18DC2B9F4 for ; Tue, 22 Jun 2021 15:02:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 237566113D for ; Tue, 22 Jun 2021 15:02:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 237566113D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 183066B005D; Tue, 22 Jun 2021 11:02:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 15BA86B006E; Tue, 22 Jun 2021 11:02:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F16696B0072; Tue, 22 Jun 2021 11:02:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id B4E3B6B005D for ; Tue, 22 Jun 2021 11:02:18 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id EBB78181AEF07 for ; Tue, 22 Jun 2021 15:02:18 +0000 (UTC) X-FDA: 78281675556.39.29220AF Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf29.hostedemail.com (Postfix) with ESMTP id 551C03501 for ; Tue, 22 Jun 2021 15:02:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=nGqycCg4dL2oA7kAkut9rWsAUoBdAodgNwEAzHrJgNs=; b=TmtUPO2zNjxDczTHwnr4DshAYU kzsCE/DQmB0Bc6MXLZl2mo92l551vsJrNHB4R0LulUCpgq+jSBe+hvBndDOZEi7SB33LDTQJgrEdk V4+YouXY1am/V1ksXtUAa6FxXV0hq7vdgL0KR8nbCOGfE0sS7u/Ah58S1VppaVaYlzmrR47UMQzlg 8IuCvLhGsSZ+W7nGk9okWiGsN0IJGWJ+EG/ShXgC4SMX+Cq3jm7e5RRHlE33TOr7mWd5wU4y8lttl ShjVYC/pmB/bg5BHTX+6g/VDNWl/eSDAbQqoqDProVMptKw2gwVc6/p8NRYU53y+gnjwxB2Phj2UG IPb8RixQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lvht9-00EPhv-D0; Tue, 22 Jun 2021 15:00:53 +0000 Date: Tue, 22 Jun 2021 16:00:31 +0100 From: Matthew Wilcox To: Dave Hansen Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, "Shutemov, Kirill" , Michael Ellerman , Benjamin Herrenschmidt , Catalin Marinas , Will Deacon Subject: Re: [LSF/MM TOPIC] Impact on core mm from new hardware features Message-ID: References: <51d3010b-6324-2441-42c0-27bb536c897d@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51d3010b-6324-2441-42c0-27bb536c897d@intel.com> Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=TmtUPO2z; dmarc=none; spf=none (imf29.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Rspamd-Server: rspam02 X-Stat-Signature: 8yxqzuwm7bp18dwf4zye796ijzuwogho X-Rspamd-Queue-Id: 551C03501 X-HE-Tag: 1624374133-832018 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jun 22, 2021 at 07:55:48AM -0700, Dave Hansen wrote: > There should be enough x86 folks around, but I'd love to hear from the > ARM and powerpc people as well. Possibly also s390. eg f28d43636d6f seems very similar to one of the things Intel wants. > Here are a few mostly Intel-specific things I'd like to discuss. > However, all of these either have analogs on other architectures or are > implemented by other x86 vendors. > > * Shadow Stacks - requires new Copy-on-Read memory type. Creates > application mappings which are effectively PROT_NONE, but which are > implicitly accessible by the hardware. > * Linear Address Masking (LAM) - Similar to ARM's Top Byte Ignore > (TBI). Repurpose some virtual address bits to store metadata. Intel > implementation can sacrifice user address space. Offloads some of > the work the compiler does in ASAN implementations. > * Supervisor Protection Keys - Extends Memory Protection Keys (pkeys) > to kernel mappings. > * TDX - VMs that don't trust the hypervisor. Requires unmapping guest > memory from userspace and possibly the host kernel.