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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 66D67C433ED for ; Thu, 20 May 2021 13:02:36 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id D085C611AD for ; Thu, 20 May 2021 13:02:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D085C611AD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6FFAA4B373; Thu, 20 May 2021 09:02:35 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iy6UYjZJ93Ug; Thu, 20 May 2021 09:02:33 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A7BBB4B35E; Thu, 20 May 2021 09:02:33 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7E8B54B354 for ; Thu, 20 May 2021 09:02:32 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dNU5Oq76G0lK for ; Thu, 20 May 2021 09:02:31 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 51E374B2F2 for ; Thu, 20 May 2021 09:02:31 -0400 (EDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id 686BB61184; Thu, 20 May 2021 13:02:27 +0000 (UTC) Date: Thu, 20 May 2021 14:02:25 +0100 From: Catalin Marinas To: Steven Price Subject: Re: [PATCH v12 3/8] arm64: mte: Sync tags for pages where PTE is untagged Message-ID: <20210520130224.GE12251@arm.com> References: <20210517123239.8025-1-steven.price@arm.com> <20210517123239.8025-4-steven.price@arm.com> <20210519180610.GE21619@arm.com> <3bac3a47-9f96-c7bf-e401-fdef60dcc9d8@arm.com> <20210520122550.GD12251@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210520122550.GD12251@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: "Dr. David Alan Gilbert" , qemu-devel@nongnu.org, Marc Zyngier , Juan Quintela , Richard Henderson , linux-kernel@vger.kernel.org, Dave Martin , linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Will Deacon , kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Thu, May 20, 2021 at 01:25:50PM +0100, Catalin Marinas wrote: > On Thu, May 20, 2021 at 12:55:21PM +0100, Steven Price wrote: > > The problem I hit is one of include dependencies: > > > > is_swap_pte() is defined (as a static inline) in > > include/linux/swapops.h. However the definition depends on > > pte_none()/pte_present() which are defined in pgtable.h - so there's a > > circular dependency. > > > > Open coding is_swap_pte() in set_pte_at() works, but it's a bit ugly. > > Any ideas on how to improve on the below? > > > > if (system_supports_mte() && pte_present(pte) && > > pte_access_permitted(pte, false) && !pte_special(pte)) { > > pte_t old_pte = READ_ONCE(*ptep); > > /* > > * We only need to synchronise if the new PTE has tags enabled > > * or if swapping in (in which case another mapping may have > > * set tags in the past even if this PTE isn't tagged). > > * (!pte_none() && !pte_present()) is an open coded version of > > * is_swap_pte() > > */ > > if (pte_tagged(pte) || (!pte_none(pte) && !pte_present(pte))) > > mte_sync_tags(old_pte, pte); > > } > > That's why I avoided testing my suggestion ;). I think we should just > add !pte_none() in there with a comment that it may be a swap pte and > use the is_swap_pte() again on the mte_sync_tags() path. We already have > the pte_present() check. Correction - pte_present() checks the new pte only, we need another for the old pte. So it looks like we'll open-code is_swap_pte(). -- Catalin _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6682AC433B4 for ; Thu, 20 May 2021 13:04:20 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0E87B610A8 for ; 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Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1ljiJq-00GLtS-OT for linux-arm-kernel@lists.infradead.org; Thu, 20 May 2021 13:02:32 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 686BB61184; Thu, 20 May 2021 13:02:27 +0000 (UTC) Date: Thu, 20 May 2021 14:02:25 +0100 From: Catalin Marinas To: Steven Price Cc: Marc Zyngier , Will Deacon , James Morse , Julien Thierry , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dave Martin , Mark Rutland , Thomas Gleixner , qemu-devel@nongnu.org, Juan Quintela , "Dr. David Alan Gilbert" , Richard Henderson , Peter Maydell , Haibo Xu , Andrew Jones Subject: Re: [PATCH v12 3/8] arm64: mte: Sync tags for pages where PTE is untagged Message-ID: <20210520130224.GE12251@arm.com> References: <20210517123239.8025-1-steven.price@arm.com> <20210517123239.8025-4-steven.price@arm.com> <20210519180610.GE21619@arm.com> <3bac3a47-9f96-c7bf-e401-fdef60dcc9d8@arm.com> <20210520122550.GD12251@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210520122550.GD12251@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210520_060230_836884_61FA4B63 X-CRM114-Status: GOOD ( 20.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, May 20, 2021 at 01:25:50PM +0100, Catalin Marinas wrote: > On Thu, May 20, 2021 at 12:55:21PM +0100, Steven Price wrote: > > The problem I hit is one of include dependencies: > > > > is_swap_pte() is defined (as a static inline) in > > include/linux/swapops.h. However the definition depends on > > pte_none()/pte_present() which are defined in pgtable.h - so there's a > > circular dependency. > > > > Open coding is_swap_pte() in set_pte_at() works, but it's a bit ugly. > > Any ideas on how to improve on the below? > > > > if (system_supports_mte() && pte_present(pte) && > > pte_access_permitted(pte, false) && !pte_special(pte)) { > > pte_t old_pte = READ_ONCE(*ptep); > > /* > > * We only need to synchronise if the new PTE has tags enabled > > * or if swapping in (in which case another mapping may have > > * set tags in the past even if this PTE isn't tagged). > > * (!pte_none() && !pte_present()) is an open coded version of > > * is_swap_pte() > > */ > > if (pte_tagged(pte) || (!pte_none(pte) && !pte_present(pte))) > > mte_sync_tags(old_pte, pte); > > } > > That's why I avoided testing my suggestion ;). I think we should just > add !pte_none() in there with a comment that it may be a swap pte and > use the is_swap_pte() again on the mte_sync_tags() path. We already have > the pte_present() check. Correction - pte_present() checks the new pte only, we need another for the old pte. So it looks like we'll open-code is_swap_pte(). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6150CC433B4 for ; Thu, 20 May 2021 13:03:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E287610A8 for ; Thu, 20 May 2021 13:03:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243137AbhETNE6 (ORCPT ); Thu, 20 May 2021 09:04:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:36648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239964AbhETNDw (ORCPT ); Thu, 20 May 2021 09:03:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 686BB61184; Thu, 20 May 2021 13:02:27 +0000 (UTC) Date: Thu, 20 May 2021 14:02:25 +0100 From: Catalin Marinas To: Steven Price Cc: Marc Zyngier , Will Deacon , James Morse , Julien Thierry , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dave Martin , Mark Rutland , Thomas Gleixner , qemu-devel@nongnu.org, Juan Quintela , "Dr. David Alan Gilbert" , Richard Henderson , Peter Maydell , Haibo Xu , Andrew Jones Subject: Re: [PATCH v12 3/8] arm64: mte: Sync tags for pages where PTE is untagged Message-ID: <20210520130224.GE12251@arm.com> References: <20210517123239.8025-1-steven.price@arm.com> <20210517123239.8025-4-steven.price@arm.com> <20210519180610.GE21619@arm.com> <3bac3a47-9f96-c7bf-e401-fdef60dcc9d8@arm.com> <20210520122550.GD12251@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210520122550.GD12251@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 20, 2021 at 01:25:50PM +0100, Catalin Marinas wrote: > On Thu, May 20, 2021 at 12:55:21PM +0100, Steven Price wrote: > > The problem I hit is one of include dependencies: > > > > is_swap_pte() is defined (as a static inline) in > > include/linux/swapops.h. However the definition depends on > > pte_none()/pte_present() which are defined in pgtable.h - so there's a > > circular dependency. > > > > Open coding is_swap_pte() in set_pte_at() works, but it's a bit ugly. > > Any ideas on how to improve on the below? > > > > if (system_supports_mte() && pte_present(pte) && > > pte_access_permitted(pte, false) && !pte_special(pte)) { > > pte_t old_pte = READ_ONCE(*ptep); > > /* > > * We only need to synchronise if the new PTE has tags enabled > > * or if swapping in (in which case another mapping may have > > * set tags in the past even if this PTE isn't tagged). > > * (!pte_none() && !pte_present()) is an open coded version of > > * is_swap_pte() > > */ > > if (pte_tagged(pte) || (!pte_none(pte) && !pte_present(pte))) > > mte_sync_tags(old_pte, pte); > > } > > That's why I avoided testing my suggestion ;). I think we should just > add !pte_none() in there with a comment that it may be a swap pte and > use the is_swap_pte() again on the mte_sync_tags() path. We already have > the pte_present() check. Correction - pte_present() checks the new pte only, we need another for the old pte. So it looks like we'll open-code is_swap_pte(). -- Catalin 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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6EBD3C433ED for ; Thu, 20 May 2021 13:03:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1E402610A8 for ; Thu, 20 May 2021 13:03:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E402610A8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52918 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ljiKm-0000Ut-6v for qemu-devel@archiver.kernel.org; Thu, 20 May 2021 09:03:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40048) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ljiJu-0007iF-1P for qemu-devel@nongnu.org; Thu, 20 May 2021 09:02:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:53582) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ljiJr-0005WO-Rc for qemu-devel@nongnu.org; Thu, 20 May 2021 09:02:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 686BB61184; Thu, 20 May 2021 13:02:27 +0000 (UTC) Date: Thu, 20 May 2021 14:02:25 +0100 From: Catalin Marinas To: Steven Price Subject: Re: [PATCH v12 3/8] arm64: mte: Sync tags for pages where PTE is untagged Message-ID: <20210520130224.GE12251@arm.com> References: <20210517123239.8025-1-steven.price@arm.com> <20210517123239.8025-4-steven.price@arm.com> <20210519180610.GE21619@arm.com> <3bac3a47-9f96-c7bf-e401-fdef60dcc9d8@arm.com> <20210520122550.GD12251@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210520122550.GD12251@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Received-SPF: pass client-ip=198.145.29.99; envelope-from=cmarinas@kernel.org; helo=mail.kernel.org X-Spam_score_int: -66 X-Spam_score: -6.7 X-Spam_bar: ------ X-Spam_report: (-6.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , "Dr. David Alan Gilbert" , Andrew Jones , Haibo Xu , Suzuki K Poulose , qemu-devel@nongnu.org, Marc Zyngier , Juan Quintela , Richard Henderson , linux-kernel@vger.kernel.org, Dave Martin , James Morse , linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Will Deacon , kvmarm@lists.cs.columbia.edu, Julien Thierry Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, May 20, 2021 at 01:25:50PM +0100, Catalin Marinas wrote: > On Thu, May 20, 2021 at 12:55:21PM +0100, Steven Price wrote: > > The problem I hit is one of include dependencies: > > > > is_swap_pte() is defined (as a static inline) in > > include/linux/swapops.h. However the definition depends on > > pte_none()/pte_present() which are defined in pgtable.h - so there's a > > circular dependency. > > > > Open coding is_swap_pte() in set_pte_at() works, but it's a bit ugly. > > Any ideas on how to improve on the below? > > > > if (system_supports_mte() && pte_present(pte) && > > pte_access_permitted(pte, false) && !pte_special(pte)) { > > pte_t old_pte = READ_ONCE(*ptep); > > /* > > * We only need to synchronise if the new PTE has tags enabled > > * or if swapping in (in which case another mapping may have > > * set tags in the past even if this PTE isn't tagged). > > * (!pte_none() && !pte_present()) is an open coded version of > > * is_swap_pte() > > */ > > if (pte_tagged(pte) || (!pte_none(pte) && !pte_present(pte))) > > mte_sync_tags(old_pte, pte); > > } > > That's why I avoided testing my suggestion ;). I think we should just > add !pte_none() in there with a comment that it may be a swap pte and > use the is_swap_pte() again on the mte_sync_tags() path. We already have > the pte_present() check. Correction - pte_present() checks the new pte only, we need another for the old pte. So it looks like we'll open-code is_swap_pte(). -- Catalin