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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5FB31CCA47C for ; Thu, 23 Jun 2022 20:01:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id DC73841624; Thu, 23 Jun 2022 20:01:45 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org DC73841624 Authentication-Results: smtp4.osuosl.org; dkim=fail reason="signature verification failed" (2048-bit key, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=UdqzXgp2 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zh9EDrCsGSs7; Thu, 23 Jun 2022 20:01:44 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTPS id 5627A41498; Thu, 23 Jun 2022 20:01:44 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 5627A41498 Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2E4E4C0039; Thu, 23 Jun 2022 20:01:44 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id CFB6CC002D; Thu, 23 Jun 2022 20:01:41 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 9E297415A5; Thu, 23 Jun 2022 20:01:41 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 9E297415A5 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WUB6lyXw5df0; Thu, 23 Jun 2022 20:01:40 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 91401415BE X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from NAM11-BN8-obe.outbound.protection.outlook.com (mail-bn8nam11on2040.outbound.protection.outlook.com [40.107.236.40]) by smtp4.osuosl.org (Postfix) with ESMTPS id 91401415BE; Thu, 23 Jun 2022 20:01:40 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Co4GHUa5WYY6rVCIoyjlQRDERyL3FGc5U3ZiV0/YSevyIG5k5c1Lq68AttlssKew+EIsWlygIXgNMxMFgdwZEgvZyP5Yaahox9TC+zRtChniEK3Eew8hWyn8kxG02++2hcXaviStyjEqJ3+fDWBKIJa7C7D3btlemFm3jFG4BFaoB1EiGCb6Zd+4JFVFREwEW7vE+1vOSnTnj3En//IoXr5w/9D5R8HXFLJmfmsNshxu9YdA2iIt+oPJzLGgk/9Wv9Iyc+ui2itbgmPJ5EJQB+ERaBwwkkm1Zih5Ry68LhE1jg4UcOEBZ4wfLqLUtckWAeX3MLalnckgRG+ltN/0YQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=cgJ77wZrDNZZI/c74qOyQalK+y4UD39aNlCVjefkCFU=; b=jcQNyoDxf9DZ28cF1cY8UrK5SXvOHuE98dl7iyP0PjcjWC+kM26bgPbljF3H+CESlLLM7Uxev0Be/1yztLTewuTx/qOzgSRSy+Si7jekukMgMixSOiNmBAs8PHaq8MgAl/mHuevqs5FZBYS8lwb8U0gBp6OlVL4CrlP9WrNqC7HF9wYTpsAxh37G0PA0s9fwHMSIcsWuRZrRL9uLy+ojVZ7hRPqwfpAUHZMfrW1ZKgiJ6rjuK+GO/EGSma5mMSDTxvYhP7oA97c/evHB7C9WS0voO7/BlXS7W3gZtd0oheBbxTqOV2BkaBXH8SmH0TJ7B7I2XIQiepvlFQDHCQycUg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 12.22.5.236) smtp.rcpttodomain=linux.intel.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=cgJ77wZrDNZZI/c74qOyQalK+y4UD39aNlCVjefkCFU=; b=UdqzXgp2vPSZy6Lt6lbHAFTnWPiadhpa8O1Y/fnR2uJ/8E5TW7TdKCZyzC6zGdSi5Fnn4j3ABwyZ1rvIEZo3LEF3E3h3p8g9c22R69nDANYUj2yN2C6HIRuCy6Uf06uuIpsxZGNE+q+iYBZIMHXsWLKROxJvlTo4pxbqjLjBK1Fnlis9BhEe8COX0+LCC1z2Mh5R3iMuNoUuz1oa0kWLOSSMv4SH9twNtyEPY/EmZSHTBYKqwUx5TK5rj+vdWg0aVvpw2kKc3R3Q4BRkd0j34oGAzEOmeWOFi0rUkHP9RSEKjI1UktHX+vNvhRm8bVJGLpAC5zv5D4/F+y9f3Y8ecQ== Received: from DM6PR03CA0077.namprd03.prod.outlook.com (2603:10b6:5:333::10) by CH2PR12MB3813.namprd12.prod.outlook.com (2603:10b6:610:2c::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5353.18; Thu, 23 Jun 2022 20:01:37 +0000 Received: from DM6NAM11FT021.eop-nam11.prod.protection.outlook.com (2603:10b6:5:333:cafe::a0) by DM6PR03CA0077.outlook.office365.com (2603:10b6:5:333::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5373.15 via Frontend Transport; Thu, 23 Jun 2022 20:01:37 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 12.22.5.236) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 12.22.5.236 as permitted sender) receiver=protection.outlook.com; client-ip=12.22.5.236; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (12.22.5.236) by DM6NAM11FT021.mail.protection.outlook.com (10.13.173.76) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.20.5373.15 via Frontend Transport; Thu, 23 Jun 2022 20:01:37 +0000 Received: from rnnvmail204.nvidia.com (10.129.68.6) by DRHQMAIL109.nvidia.com (10.27.9.19) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Thu, 23 Jun 2022 20:01:36 +0000 Received: from rnnvmail204.nvidia.com (10.129.68.6) by rnnvmail204.nvidia.com (10.129.68.6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.26; Thu, 23 Jun 2022 13:01:35 -0700 Received: from Asurada-Nvidia.nvidia.com (10.127.8.10) by mail.nvidia.com (10.129.68.6) with Microsoft SMTP Server id 15.2.986.26 via Frontend Transport; Thu, 23 Jun 2022 13:01:33 -0700 To: , , , , , , , , , , , , , , Subject: [PATCH v3 2/5] vfio/iommu_type1: Prefer to reuse domains vs match enforced cache coherency Date: Thu, 23 Jun 2022 13:00:26 -0700 Message-ID: <20220623200029.26007-3-nicolinc@nvidia.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220623200029.26007-1-nicolinc@nvidia.com> References: <20220623200029.26007-1-nicolinc@nvidia.com> MIME-Version: 1.0 X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 75f04611-1fe9-4f3a-87e4-08da55532e48 X-MS-TrafficTypeDiagnostic: CH2PR12MB3813:EE_ X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 3ANiL2ol6JRxsySqqh5zZx+M9SaAgOzRGLmWTi+hka87xak42yNXAmkib7DaHXljd212hiDpFUmRgWRDgqD0cjwSyXDZBuOAbV5EVT0j78H7acGoDFjleMUtDsEzENZ3/z8isiISbIpHQTRMzRSXUQZdyYzb6BeYLprTY8jtcYQSiCxVKWfLWoF182VqwiDfWOI5Uc885D5AOxnRqibLg+mlk8ijioJwWpdikqkyRM0YTCjBpep573T5KSb4V0KXpYqia/TaJYtuGggA9CtvJ00Wxy8+CiduZKj5LJXMiRzQIN007IEIz7gG0eZQXEV1NC3hjEZ4kEBXPZ348m3VO8ylFGfuZc8L2pmqv2P+BW30FewDzZcDWdkFgPFjKJCEvZq623uS1FB9SaC0RK6L/y9vy6HINy0OdKVqztPmGBdilDea1N+e/okIIeVr0cvRNrfPnJSiaaXa3xoYUoCYVBDZgwiTzt1XRPR4wiCNjhOk+Zh4V8XiOn957EZlDxglmK63NeXhmjkNYse2KNuQl+59uLmkBGZps7/dgBz6hhlksXTDy1fSkYLQylmYtpgXOjCIcBztRcEYhZ7bKBTwgb74i+nBLIEHtjmrXS3YqHF6NlIyzFg6N498MXP2NyRR4W658yDkwOYQDLIIw3VjcnJXANUL4kYjKb9mMJW2EVxj7Y7rd1xYQeRmpYQVq6DNgVBPWxUGAJ0y8BF2W390Cs3CgCK2ES7i51IwdNrugJQeb2IDjypeq5umq2BRYjgGOKqxa8GeYsh2dEpFziEhIwIlF2h2mmsP/DD/V1/DgBmezoP8fWXzeFdxYApib4FPFnq8naJQ9D8gM0qo31k036HySx0oTkGmquRD7ckNeCiaAL7mM5WNYfK1c0fWPmrpULTI6WP56IsVoqAsiSQoCw== X-Forefront-Antispam-Report: CIP:12.22.5.236; CTRY:US; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:mail.nvidia.com; PTR:InfoNoRecords; CAT:NONE; SFS:(13230016)(4636009)(376002)(346002)(39860400002)(396003)(136003)(40470700004)(36840700001)(46966006)(8936002)(36860700001)(7416002)(41300700001)(336012)(356005)(1076003)(40460700003)(83380400001)(36756003)(186003)(47076005)(70586007)(5660300002)(70206006)(426003)(2616005)(82310400005)(26005)(7696005)(478600001)(8676002)(6666004)(110136005)(54906003)(921005)(316002)(2906002)(82740400003)(7406005)(86362001)(4326008)(40480700001)(81166007)(83996005)(36900700001)(2101003); DIR:OUT; SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Jun 2022 20:01:37.2248 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 75f04611-1fe9-4f3a-87e4-08da55532e48 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a; Ip=[12.22.5.236]; Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT021.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB3813 Cc: jordan@cosmicpenguin.net, thierry.reding@gmail.com, alyssa@rosenzweig.io, linux-s390@vger.kernel.org, kvm@vger.kernel.org, jonathanh@nvidia.com, yangyingliang@huawei.com, gerald.schaefer@linux.ibm.com, linux-arm-msm@vger.kernel.org, christophe.jaillet@wanadoo.fr, linux-tegra@vger.kernel.org, tglx@linutronix.de, virtualization@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, cohuck@redhat.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-mediatek@lists.infradead.org, dwmw2@infradead.org 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: , From: Nicolin Chen via iommu Reply-To: Nicolin Chen Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" From: Jason Gunthorpe The KVM mechanism for controlling wbinvd is based on OR of the coherency property of all devices attached to a guest, no matter whether those devices are attached to a single domain or multiple domains. On the other hand, the benefit to using separate domains was that those devices attached to domains supporting enforced cache coherency always mapped with the attributes necessary to provide that feature, therefore if a non-enforced domain was dropped, the associated group removal would re-trigger an evaluation by KVM. In practice however, the only known cases of such mixed domains included an Intel IGD device behind an IOMMU lacking snoop control, where such devices do not support hotplug, therefore this scenario lacks testing and is not considered sufficiently relevant to support. After all, KVM won't take advantage of trying to push a device that could do enforced cache coherency to a dedicated domain vs re-using an existing domain, which is non-coherent. Simplify this code and eliminate the test. This removes the only logic that needed to have a dummy domain attached prior to searching for a matching domain and simplifies the next patches. It's unclear whether we want to further optimize the Intel driver to update the domain coherency after a device is detached from it, at least not before KVM can be verified to handle such dynamics in related emulation paths (wbinvd, vcpu load, write_cr0, ept, etc.). In reality we don't see an usage requiring such optimization as the only device which imposes such non-coherency is Intel GPU which even doesn't support hotplug/hot remove. Signed-off-by: Jason Gunthorpe Reviewed-by: Kevin Tian Signed-off-by: Nicolin Chen --- drivers/vfio/vfio_iommu_type1.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index c13b9290e357..f4e3b423a453 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2285,9 +2285,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, * testing if they're on the same bus_type. */ list_for_each_entry(d, &iommu->domain_list, next) { - if (d->domain->ops == domain->domain->ops && - d->enforce_cache_coherency == - domain->enforce_cache_coherency) { + if (d->domain->ops == domain->domain->ops) { iommu_detach_group(domain->domain, group->iommu_group); if (!iommu_attach_group(d->domain, group->iommu_group)) { -- 2.17.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu