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=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 1A274C433EF for ; Tue, 21 Sep 2021 16:53:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A4BB361183 for ; Tue, 21 Sep 2021 16:52:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A4BB361183 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E698A900003; Tue, 21 Sep 2021 12:52:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DF1C0900002; Tue, 21 Sep 2021 12:52:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C91F6900003; Tue, 21 Sep 2021 12:52:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0160.hostedemail.com [216.40.44.160]) by kanga.kvack.org (Postfix) with ESMTP id B518C900002 for ; Tue, 21 Sep 2021 12:52:58 -0400 (EDT) Received: from smtpin34.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 660DE8249980 for ; Tue, 21 Sep 2021 16:52:58 +0000 (UTC) X-FDA: 78612175236.34.8FCA221 Received: from mail-oi1-f174.google.com (mail-oi1-f174.google.com [209.85.167.174]) by imf07.hostedemail.com (Postfix) with ESMTP id 2AC0010000A8 for ; Tue, 21 Sep 2021 16:52:57 +0000 (UTC) Received: by mail-oi1-f174.google.com with SMTP id 6so22235oiy.8 for ; Tue, 21 Sep 2021 09:52:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=sKyAaMyjba5UGAL+Ffx1m6B2HtqFlKzn3qa+s7JDR7A=; b=n97JREXFhF8uInD9jyglFF3bXcJ3A2tDq5l8e5eUvblCKJfUsPd++5B6ezoWO6/LFe 4Y5/mxWmaiIXW9v1MHV1Kizx78BAQLZ0dTJstd/CJn+UfSIwv0svWqYAb2/YJ5tEwW+D eIP5m5JNaBB/Vjzq3/ByT2um9Eu4/bN0vFr8aBmqTFMHHxbVil6l8OD9LzrXa3D38VhC nKArVeO9Gh1n9PCM46b5FIIjZi35QgIR2rDfhIeU8LM8CcAW8OYcSyPsjEabryN9xnWR /vnsHiRHXn8zKZ2BZYHjIOW64R+ez8OYcplpyOxjakXp0nRZ+szI8x8uJN0K1STCZUUj YMIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sKyAaMyjba5UGAL+Ffx1m6B2HtqFlKzn3qa+s7JDR7A=; b=NaI2oY4f1sC4EMYBSzQpr3AXWMz/K6GdcNO81Y0tRVpHEdaOgvCQ+zGLtJ14ui8wMr B13et5AFPGAfv/tAXFjYB0AaL1i6X/O8jTe/jq57ounipBOvBQklxiDLBl1MCN0Eitn1 aaOS1g5vHFVLy697KCtu5iqf9GZrGLkTXWk08MXc4zDn4LC1AnttXxM/+VX4ocjmskgX 6sEYo+XCSDYXVS59L3SrvuqY0JB2QE2GJV9wyu/Sr5t3gMYDNuavWgz/U8AsFpe3+PsN O0hbJBQ6Br/k8TuLp1cj1ZlhEmHDKyQU/K1MDAV6wkgFrksK7h6Uud8q5gPZD/OlNciM ZgMA== X-Gm-Message-State: AOAM533pwQW7QY+WkVHcm39Qaq2RXw9xrVtymV3HtFfSJbjlti8qFJSA y69MTwznTl4hTAyQqLkjZJfpLUmYJa0zV71HJhMdEw== X-Google-Smtp-Source: ABdhPJzUeS3r23NqEgDB/MiQoZUl05DsufRAMemqPlo77Pzz0H9z1H0SjpKWD8D1iZGN3L5glJj0AqUOiy6xau5v+9I= X-Received: by 2002:aca:f189:: with SMTP id p131mr4542727oih.128.1632243177063; Tue, 21 Sep 2021 09:52:57 -0700 (PDT) MIME-Version: 1.0 References: <20210205151631.43511-1-kirill.shutemov@linux.intel.com> <20210207141104.ikxbdxhoisgqaoio@box> In-Reply-To: <20210207141104.ikxbdxhoisgqaoio@box> From: Dmitry Vyukov Date: Tue, 21 Sep 2021 18:52:44 +0200 Message-ID: Subject: Re: [RFC 0/9] Linear Address Masking enabling To: "Kirill A. Shutemov" Cc: "Kirill A. Shutemov" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , "the arch/x86 maintainers" , Andrey Ryabinin , Alexander Potapenko , Catalin Marinas , Will Deacon , "H . J . Lu" , Andi Kleen , Linux-MM , LKML , "Carlos O'Donell" , Marco Elver , Taras Madan Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 2AC0010000A8 X-Stat-Signature: xmux7y7hhtm9mwp9wown8ob4azigfruz Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=n97JREXF; spf=pass (imf07.hostedemail.com: domain of dvyukov@google.com designates 209.85.167.174 as permitted sender) smtp.mailfrom=dvyukov@google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1632243177-707416 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 Sun, 7 Feb 2021 at 15:11, Kirill A. Shutemov wrote: > > On Sun, Feb 07, 2021 at 09:24:23AM +0100, Dmitry Vyukov wrote: > > On Fri, Feb 5, 2021 at 4:16 PM Kirill A. Shutemov > > wrote: > > > > > > Linear Address Masking[1] (LAM) modifies the checking that is applied to > > > 64-bit linear addresses, allowing software to use of the untranslated > > > address bits for metadata. > > > > > > The patchset brings support for LAM for userspace addresses. > > > > > > The most sensitive part of enabling is change in tlb.c, where CR3 flags > > > get set. Please take a look that what I'm doing makes sense. > > > > > > The patchset is RFC quality and the code requires more testing before it > > > can be applied. > > > > > > The userspace API is not finalized yet. The patchset extends API used by > > > ARM64: PR_GET/SET_TAGGED_ADDR_CTRL. The API is adjusted to not imply ARM > > > TBI: it now allows to request a number of bits of metadata needed and > > > report where these bits are located in the address. > > > > > > There's an alternative proposal[2] for the API based on Intel CET > > > interface. Please let us know if you prefer one over another. > > > > > > The feature competes for bits with 5-level paging: LAM_U48 makes it > > > impossible to map anything about 47-bits. The patchset made these > > > capability mutually exclusive: whatever used first wins. LAM_U57 can be > > > combined with mappings above 47-bits. > > > > > > I include QEMU patch in case if somebody wants to play with the feature. > > > > Exciting! Do you plan to send the QEMU patch to QEMU? > > Sure. After more testing, once I'm sure it's conforming to the hardware. A follow up after H.J.'s LPC talk: https://linuxplumbersconf.org/event/11/contributions/1010/ (also +Carlos) As far as I understood, this kernel series depends on the Intel CET patches. Where are these compiler-rt patches that block gcc support?