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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 D3E9EC48BDF for ; Tue, 15 Jun 2021 13:08:31 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 7256E6146E for ; Tue, 15 Jun 2021 13:08:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7256E6146E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 3EF3B60849; Tue, 15 Jun 2021 13:08:31 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id u1HhDUrUAbaN; Tue, 15 Jun 2021 13:08:29 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTPS id AACAE607B5; Tue, 15 Jun 2021 13:08:28 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6A8DFC000E; Tue, 15 Jun 2021 13:08:28 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id D256FC000B for ; Tue, 15 Jun 2021 13:08:26 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id CDC56402A1 for ; Tue, 15 Jun 2021 13:08:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id QIybmNin6Cze for ; Tue, 15 Jun 2021 13:08:23 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp2.osuosl.org (Postfix) with ESMTP id 52F424000B for ; Tue, 15 Jun 2021 13:08:23 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B891311D4; Tue, 15 Jun 2021 06:08:22 -0700 (PDT) Received: from [10.57.9.136] (unknown [10.57.9.136]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8234F3F719; Tue, 15 Jun 2021 06:08:21 -0700 (PDT) Subject: Re: [PATCH v3 2/6] iommu/amd: Do not use flush-queue when NpCache is on To: Nadav Amit , Joerg Roedel References: <20210607182541.119756-1-namit@vmware.com> <20210607182541.119756-3-namit@vmware.com> From: Robin Murphy Message-ID: Date: Tue, 15 Jun 2021 14:08:16 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210607182541.119756-3-namit@vmware.com> Content-Language: en-GB Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Nadav Amit , Jiajun Cao , Will Deacon X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2021-06-07 19:25, Nadav Amit wrote: > From: Nadav Amit > > Do not use flush-queue on virtualized environments, where the NpCache > capability of the IOMMU is set. This is required to reduce > virtualization overheads. > > This change follows a similar change to Intel's VT-d and a detailed > explanation as for the rationale is described in commit 29b32839725f > ("iommu/vt-d: Do not use flush-queue when caching-mode is on"). > > Cc: Joerg Roedel > Cc: Will Deacon > Cc: Jiajun Cao > Cc: Robin Murphy > Cc: Lu Baolu > Cc: iommu@lists.linux-foundation.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Nadav Amit > --- > drivers/iommu/amd/init.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c > index d006724f4dc2..ba3b76ed776d 100644 > --- a/drivers/iommu/amd/init.c > +++ b/drivers/iommu/amd/init.c > @@ -1850,8 +1850,13 @@ static int __init iommu_init_pci(struct amd_iommu *iommu) > if (ret) > return ret; > > - if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE)) > + if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE)) { > + if (!amd_iommu_unmap_flush) > + pr_warn_once("IOMMU batching is disabled due to virtualization"); Nit: you can just use pr_warn() (or arguably pr_info()) since the explicit conditions already only match once. Speaking of which, it might be better to use amd_iommu_np_cache instead, since other patches are planning to clean up the last remnants of amd_iommu_unmap_flush. Robin. > + > amd_iommu_np_cache = true; > + amd_iommu_unmap_flush = true; > + } > > init_iommu_perf_ctr(iommu); > > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 46A8EC48BDF for ; Tue, 15 Jun 2021 13:08:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28E32613B1 for ; Tue, 15 Jun 2021 13:08:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230246AbhFONK2 (ORCPT ); Tue, 15 Jun 2021 09:10:28 -0400 Received: from foss.arm.com ([217.140.110.172]:34890 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229951AbhFONK1 (ORCPT ); Tue, 15 Jun 2021 09:10:27 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B891311D4; Tue, 15 Jun 2021 06:08:22 -0700 (PDT) Received: from [10.57.9.136] (unknown [10.57.9.136]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8234F3F719; Tue, 15 Jun 2021 06:08:21 -0700 (PDT) Subject: Re: [PATCH v3 2/6] iommu/amd: Do not use flush-queue when NpCache is on To: Nadav Amit , Joerg Roedel Cc: Nadav Amit , Will Deacon , Jiajun Cao , Lu Baolu , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20210607182541.119756-1-namit@vmware.com> <20210607182541.119756-3-namit@vmware.com> From: Robin Murphy Message-ID: Date: Tue, 15 Jun 2021 14:08:16 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210607182541.119756-3-namit@vmware.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-06-07 19:25, Nadav Amit wrote: > From: Nadav Amit > > Do not use flush-queue on virtualized environments, where the NpCache > capability of the IOMMU is set. This is required to reduce > virtualization overheads. > > This change follows a similar change to Intel's VT-d and a detailed > explanation as for the rationale is described in commit 29b32839725f > ("iommu/vt-d: Do not use flush-queue when caching-mode is on"). > > Cc: Joerg Roedel > Cc: Will Deacon > Cc: Jiajun Cao > Cc: Robin Murphy > Cc: Lu Baolu > Cc: iommu@lists.linux-foundation.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Nadav Amit > --- > drivers/iommu/amd/init.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c > index d006724f4dc2..ba3b76ed776d 100644 > --- a/drivers/iommu/amd/init.c > +++ b/drivers/iommu/amd/init.c > @@ -1850,8 +1850,13 @@ static int __init iommu_init_pci(struct amd_iommu *iommu) > if (ret) > return ret; > > - if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE)) > + if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE)) { > + if (!amd_iommu_unmap_flush) > + pr_warn_once("IOMMU batching is disabled due to virtualization"); Nit: you can just use pr_warn() (or arguably pr_info()) since the explicit conditions already only match once. Speaking of which, it might be better to use amd_iommu_np_cache instead, since other patches are planning to clean up the last remnants of amd_iommu_unmap_flush. Robin. > + > amd_iommu_np_cache = true; > + amd_iommu_unmap_flush = true; > + } > > init_iommu_perf_ctr(iommu); > >