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 1C39AC021A4 for ; Fri, 14 Feb 2025 02:49:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 06C1E6B0083; Thu, 13 Feb 2025 21:49:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 01B576B0085; Thu, 13 Feb 2025 21:49:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E24F16B0088; Thu, 13 Feb 2025 21:49:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id C57E46B0083 for ; Thu, 13 Feb 2025 21:49:11 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 5A664A1ACB for ; Fri, 14 Feb 2025 02:49:11 +0000 (UTC) X-FDA: 83117018502.23.BCD2CA0 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) by imf15.hostedemail.com (Postfix) with ESMTP id A500CA0004 for ; Fri, 14 Feb 2025 02:49:08 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=none; spf=pass (imf15.hostedemail.com: domain of tongtiangen@huawei.com designates 45.249.212.190 as permitted sender) smtp.mailfrom=tongtiangen@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739501349; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Qdv27WOOjvDepPMV24X/lprplWgreW0f92yGmOb5lxY=; b=AMySS/JYibqWH/OdqEpddRzFoE+u/5GP5HZDvsTwilrjRiBKjuqPRlcnst0BuAZ4lIi2x7 rD4T7c4YLtScq34ZFq4Q4mbuwLow/M+38Ki9XLI5PntYYPIAmfqxOsIWcrYNIsnEQvL3rM AYWSR6PLoDJJrysus9z8FalkOQBuJ0E= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=none; spf=pass (imf15.hostedemail.com: domain of tongtiangen@huawei.com designates 45.249.212.190 as permitted sender) smtp.mailfrom=tongtiangen@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739501349; a=rsa-sha256; cv=none; b=hSuTa+jQ0L9umj0xKbhsSgqmkBJdFua+KnFRzS4zoxeKyU4i0m0o/b7Ic45Pls9GOdOKEH Bk4l7OffPJ4zY6oMGKPgDXTd/Mxo/3mdp67+yF1SmcwOx/8WvQyrj/YO6nAnHni0AVFGaO FcziGs8CzFw3O9wQM2+BJOfJzepZ/S8= Received: from mail.maildlp.com (unknown [172.19.163.17]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4YvGcX1dFHz2FdPV; Fri, 14 Feb 2025 10:45:16 +0800 (CST) Received: from kwepemk500005.china.huawei.com (unknown [7.202.194.90]) by mail.maildlp.com (Postfix) with ESMTPS id 362F01A0188; Fri, 14 Feb 2025 10:49:04 +0800 (CST) Received: from [10.174.179.234] (10.174.179.234) by kwepemk500005.china.huawei.com (7.202.194.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 14 Feb 2025 10:49:01 +0800 Message-ID: <69955002-c3b1-459d-9b42-8d07475c3fd3@huawei.com> Date: Fri, 14 Feb 2025 10:49:01 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v13 4/5] arm64: support copy_mc_[user]_highpage() To: Catalin Marinas CC: Mark Rutland , Jonathan Cameron , Mauro Carvalho Chehab , Will Deacon , Andrew Morton , James Morse , Robin Murphy , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Michael Ellerman , Nicholas Piggin , Andrey Ryabinin , Alexander Potapenko , Christophe Leroy , Aneesh Kumar K.V , "Naveen N. Rao" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , , "H. Peter Anvin" , Madhavan Srinivasan , , , , , , , Guohanjun References: <20241209024257.3618492-1-tongtiangen@huawei.com> <20241209024257.3618492-5-tongtiangen@huawei.com> From: Tong Tiangen In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemk500005.china.huawei.com (7.202.194.90) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: A500CA0004 X-Stat-Signature: r6xoqr3zx1y9zpfr1ak84zf1foi97pdk X-Rspam-User: X-HE-Tag: 1739501348-37367 X-HE-Meta: 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 oFTS48SA bG/O3GkZwdBK7WQu+xbyLUgySAnHWIx3u8apTeVVSwNN2YDsrwggOeEZmtov3BjY/RY3kNshM5Y81KwiFmmf6cB0GQrXwXM1q+QnS1z/G2GarCD1Pm27orLI8b3Xwkg2+RKDanVqOLDhbjEaLgkb3RvEIse/pNIN/lDoxmK12kQ7O5KHfqQXWtx1nKdcIG+QtLKZVTDg0jML1Enfedan7mu3x9iLLQhPSg0jbG4RyohRkM5ZB93v3jWm5aT76sx0TCUCdWlensFA7YgLGTpUnbECgkrY9I5ZZJh72 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: List-Subscribe: List-Unsubscribe: 在 2025/2/13 1:11, Catalin Marinas 写道: > On Mon, Dec 09, 2024 at 10:42:56AM +0800, Tong Tiangen wrote: >> Currently, many scenarios that can tolerate memory errors when copying page >> have been supported in the kernel[1~5], all of which are implemented by >> copy_mc_[user]_highpage(). arm64 should also support this mechanism. >> >> Due to mte, arm64 needs to have its own copy_mc_[user]_highpage() >> architecture implementation, macros __HAVE_ARCH_COPY_MC_HIGHPAGE and >> __HAVE_ARCH_COPY_MC_USER_HIGHPAGE have been added to control it. >> >> Add new helper copy_mc_page() which provide a page copy implementation with >> hardware memory error safe. The code logic of copy_mc_page() is the same as >> copy_page(), the main difference is that the ldp insn of copy_mc_page() >> contains the fixup type EX_TYPE_KACCESS_ERR_ZERO_MEM_ERR, therefore, the >> main logic is extracted to copy_page_template.S. In addition, the fixup of >> MOPS insn is not considered at present. > > Could we not add the exception table entry permanently but ignore the > exception table entry if it's not on the do_sea() path? That would save > some code duplication. I'm sorry, I didn't catch your point, that the do_sea() and non do_sea() paths use different exception tables? My understanding is that the exception table entry problem is fine. After all, the search is performed only after a fault trigger. Code duplication can be solved by extracting repeated logic to a public file. > >> diff --git a/arch/arm64/lib/copy_mc_page.S b/arch/arm64/lib/copy_mc_page.S >> new file mode 100644 >> index 000000000000..51564828c30c >> --- /dev/null >> +++ b/arch/arm64/lib/copy_mc_page.S >> @@ -0,0 +1,37 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +/* >> + * Copy a page from src to dest (both are page aligned) with memory error safe >> + * >> + * Parameters: >> + * x0 - dest >> + * x1 - src >> + * Returns: >> + * x0 - Return 0 if copy success, or -EFAULT if anything goes wrong >> + * while copying. >> + */ >> + .macro ldp1 reg1, reg2, ptr, val >> + KERNEL_MEM_ERR(9998f, ldp \reg1, \reg2, [\ptr, \val]) >> + .endm >> + >> +SYM_FUNC_START(__pi_copy_mc_page) >> +#include "copy_page_template.S" >> + >> + mov x0, #0 >> + ret >> + >> +9998: mov x0, #-EFAULT >> + ret >> + >> +SYM_FUNC_END(__pi_copy_mc_page) >> +SYM_FUNC_ALIAS(copy_mc_page, __pi_copy_mc_page) >> +EXPORT_SYMBOL(copy_mc_page) > [...] >> diff --git a/arch/arm64/lib/copy_page_template.S b/arch/arm64/lib/copy_page_template.S >> new file mode 100644 >> index 000000000000..f96c7988c93d >> --- /dev/null >> +++ b/arch/arm64/lib/copy_page_template.S >> @@ -0,0 +1,70 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only */ >> +/* >> + * Copyright (C) 2012 ARM Ltd. >> + */ >> + >> +/* >> + * Copy a page from src to dest (both are page aligned) >> + * >> + * Parameters: >> + * x0 - dest >> + * x1 - src >> + */ >> + >> +#ifdef CONFIG_AS_HAS_MOPS >> + .arch_extension mops >> +alternative_if_not ARM64_HAS_MOPS >> + b .Lno_mops >> +alternative_else_nop_endif >> + >> + mov x2, #PAGE_SIZE >> + cpypwn [x0]!, [x1]!, x2! >> + cpymwn [x0]!, [x1]!, x2! >> + cpyewn [x0]!, [x1]!, x2! >> + ret >> +.Lno_mops: >> +#endif > [...] > > So if we have FEAT_MOPS, the machine check won't work? > > Kristina is going to post MOPS support for the uaccess routines soon. > You can see how they are wired up and do something similar here. > > But I'd prefer if we had the same code, only the exception table entry > treated differently. Similarly for the MTE tag copying. >