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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0CB2FC4332F for ; Mon, 21 Nov 2022 09:52:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E9238E000A; Mon, 21 Nov 2022 04:52:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8998A8E0001; Mon, 21 Nov 2022 04:52:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 762088E000A; Mon, 21 Nov 2022 04:52:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 678528E0001 for ; Mon, 21 Nov 2022 04:52:37 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 40251C0938 for ; Mon, 21 Nov 2022 09:52:37 +0000 (UTC) X-FDA: 80156984754.14.1C5C4B1 Received: from mail-vs1-f48.google.com (mail-vs1-f48.google.com [209.85.217.48]) by imf04.hostedemail.com (Postfix) with ESMTP id DA37940003 for ; Mon, 21 Nov 2022 09:52:36 +0000 (UTC) Received: by mail-vs1-f48.google.com with SMTP id 128so10669976vsz.12 for ; Mon, 21 Nov 2022 01:52:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=TVJfUYwe5iLolb0LBkHyX82AMIwkeDuAU43Tw3iotdY=; b=PvaYgoGXPvfrAqZjxhoAM38/m+pTA0m/AuWnCy0QVpbSS+u6dt2dngcfPt8UrbFuLA TGsYYijUuZYoQRGCot7/sDmHhbsj3rx9ie3DQ8PeBqV4HRQrTH7mo/11j1v+f+TbKHw/ cIE2RbsE3tDmk82SzMMFspY2DoInj3MtlkUWjkrhOXaBAHtUWAv/3GcgomgDqU7givfg nNeSrwu6s7I0jCHk+cHxUYYNc52TBCv8Zy5QPx5Mq0E4aWQQ6FNnzGlM7wNOH2X99CAJ RwknGbu65uNmxvBrY24eQVjfu2FEZWwBJifAbGj53ryaZQ3GV8cv7UxWLRWA54lIAbo+ mO/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=TVJfUYwe5iLolb0LBkHyX82AMIwkeDuAU43Tw3iotdY=; b=i4Cpr9UstxWMj+uKTd7Cp1Q8b1uUflC9m23NPkBZ80wrUORp6ue7ooJsbJXZreIjuz dep31Y9VJtjtafuMG+7lDxnxphuO8Elovf/jX6gnQ6LDzfy2YcTb3WkIH8vcvQpKBzPn +I6li7gBUlq/8SOFoaaOKrx1T2edb7kgyuo9OOsxekA8CqXPVuUZA8oqyHBvgKnD5rBW Vc6fEsLm8drkWX5L34bGlcmSgVV4O/LdJLyH5B5N7cL6R+ab/wxS3i1Ug65S+x8JsGeQ OGd3/8JeYSshVoh57rRVZ2j83UNdTXc/k1TGn/mdkaHWcCRaCR6+zglPnnqhigzC30t0 849w== X-Gm-Message-State: ANoB5plsWboqdELD7KORCRFqhF6kcRlO6FJfcKR3KCoEqzxQ93D+1LPv xe5lfY4NaYjDcF8PCjiLSwlVNNfateJ4IPC7B8oV1Q== X-Google-Smtp-Source: AA0mqf6TlIKWv3VvjEFTZJKV5E3BYblYaTU3VKPnMqcEHjGejNDE8sx3WtpkG8lhL3SAZM13/t17JvRYA0K68z91EzM= X-Received: by 2002:a67:fe01:0:b0:3af:5ff9:ed51 with SMTP id l1-20020a67fe01000000b003af5ff9ed51mr2821568vsr.46.1669024355893; Mon, 21 Nov 2022 01:52:35 -0800 (PST) MIME-Version: 1.0 References: <20221121093245.4587-1-jgross@suse.com> <40c58b1b-9b90-ccd8-1387-362de236af2a@suse.com> In-Reply-To: <40c58b1b-9b90-ccd8-1387-362de236af2a@suse.com> From: Yu Zhao Date: Mon, 21 Nov 2022 02:51:59 -0700 Message-ID: Subject: Re: [PATCH] mm: introduce arch_has_hw_pmd_young() To: Juergen Gross Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andrew Morton , Sander Eikelenboom Content-Type: text/plain; charset="UTF-8" ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=PvaYgoGX; spf=pass (imf04.hostedemail.com: domain of yuzhao@google.com designates 209.85.217.48 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669024356; a=rsa-sha256; cv=none; b=f6SFrSdelOWrALLYMnuK3jLsx/wgVZXpp05M4P+d4vKRnTCb0epuLXuDAw3VCaVnXE24Ow /jdTypGKDSGrRdKuMvl317Bysg5mofPpq3JlDUC0vOYMI9+J1+Cp6APRYPMm8EsMeBBWXL nL/XSJ4dW4yNeC3DzdDn1BypieWoya0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669024356; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TVJfUYwe5iLolb0LBkHyX82AMIwkeDuAU43Tw3iotdY=; b=J9SeuFParZjR4o/KNuKpLI9VQwe/ubdSjth9Q9eXU+3xcHbWaJ9nDo9U8zny7Ne1xIsZ8f 5o8SatWuesGZvk9fZxhwgiAX00i8OISHdYRlQlmUAjUpPE1HHtB5EYm18SKG3NrrNCGwde yR4EhkeJTujsMBfbEYtlHAcNAw6B+CQ= Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=PvaYgoGX; spf=pass (imf04.hostedemail.com: domain of yuzhao@google.com designates 209.85.217.48 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam02 X-Rspam-User: X-Stat-Signature: z16jxu6zmqde7em4ak66zgaz39w5rwck X-Rspamd-Queue-Id: DA37940003 X-HE-Tag: 1669024356-142421 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 Mon, Nov 21, 2022 at 2:50 AM Juergen Gross wrote: > > On 21.11.22 10:32, Juergen Gross wrote: > > When running as a Xen PV guests commit eed9a328aa1a ("mm: x86: add > > CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG") can cause a protection violation > > in pmdp_test_and_clear_young(): > > > > BUG: unable to handle page fault for address: ffff8880083374d0 > > #PF: supervisor write access in kernel mode > > #PF: error_code(0x0003) - permissions violation > > PGD 3026067 P4D 3026067 PUD 3027067 PMD 7fee5067 PTE 8010000008337065 > > Oops: 0003 [#1] PREEMPT SMP NOPTI > > CPU: 7 PID: 158 Comm: kswapd0 Not tainted 6.1.0-rc5-20221118-doflr+ #1 > > RIP: e030:pmdp_test_and_clear_young+0x25/0x40 > > > > This happens because the Xen hypervisor can't emulate direct writes to > > page table entries other than PTEs. > > > > This can easily be fixed by introducing arch_has_hw_pmd_young() > > similar to arch_has_hw_pte_young() and test that instead of > > CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG. > > I just spotted that I missed to update my commit message to match the > patch: > > s/arch_has_hw_pmd_young/arch_has_hw_nonleaf_pmd_young/ > > I'll wait with a resend in order to get some feedback first. Thanks. For the next spin: Acked-by: Yu Zhao