From nobody Mon Jan 26 09:20:22 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; arc=pass (i=1 dmarc=pass fromdomain=amd.com); dmarc=pass(p=quarantine dis=none) header.from=amd.com ARC-Seal: i=2; a=rsa-sha256; t=1768902885; cv=pass; d=zohomail.com; s=zohoarc; b=OYhnuutyFZDnPfTY9MVYJzaPzGeh84+D24GBg6tOPy7vXUcD2JDBfhii5ixoKk2sZNGqYJ5m0Do0MudjENOy1vbQtCY+7yFFhNAYW2+vYewJgMYMS0ccaAy7tUfrMIRz5xHUkofMSNGAFhQx7y9rMiSnEFAY+DdBUxdrFifvj2c= ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1768902885; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=tlelRD0l8IWBcWpAH3Cc0918m2Klv7LDj+1fptSjsws=; b=RTVfgNZAv7KaI6ybU3TdrvaGRLL5p5SG2g00Iu9q4hsGQVraG5lSoipH8L58PeGe3OCpPXMwzl0L/NO7fdRW/D0rTKLSCjqDnUZNu7Jd8fxjsRCe6jCvTJ7RMo2VUNGwr9lInqx+bDrISaZITNG97AoJrerUICEYOuk9f1Nlews= ARC-Authentication-Results: i=2; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; arc=pass (i=1 dmarc=pass fromdomain=amd.com); dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1768902884832411.1841066138902; Tue, 20 Jan 2026 01:54:44 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.1208565.1520736 (Exim 4.92) (envelope-from ) id 1vi8RL-00071w-IJ; Tue, 20 Jan 2026 09:54:23 +0000 Received: by outflank-mailman (output) from mailman id 1208565.1520736; Tue, 20 Jan 2026 09:54:23 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vi8RL-00071o-FD; Tue, 20 Jan 2026 09:54:23 +0000 Received: by outflank-mailman (input) for mailman id 1208565; Tue, 20 Jan 2026 09:54:21 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vi8RJ-0006Yj-J2 for xen-devel@lists.xenproject.org; Tue, 20 Jan 2026 09:54:21 +0000 Received: from CO1PR03CU002.outbound.protection.outlook.com (mail-westus2azlp170100005.outbound.protection.outlook.com [2a01:111:f403:c005::5]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id fd3d2d7c-f5e5-11f0-b15e-2bf370ae4941; Tue, 20 Jan 2026 10:54:20 +0100 (CET) Received: from PH8PR02CA0037.namprd02.prod.outlook.com (2603:10b6:510:2da::35) by DS7PR12MB5814.namprd12.prod.outlook.com (2603:10b6:8:76::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9520.12; Tue, 20 Jan 2026 09:54:13 +0000 Received: from CO1PEPF000044F7.namprd21.prod.outlook.com (2603:10b6:510:2da:cafe::69) by PH8PR02CA0037.outlook.office365.com (2603:10b6:510:2da::35) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9520.13 via Frontend Transport; Tue, 20 Jan 2026 09:54:12 +0000 Received: from satlexmb07.amd.com (165.204.84.17) by CO1PEPF000044F7.mail.protection.outlook.com (10.167.241.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9564.0 via Frontend Transport; Tue, 20 Jan 2026 09:54:12 +0000 Received: from xcbagarciav01.xilinx.com (10.180.168.240) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Tue, 20 Jan 2026 03:54:08 -0600 X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: fd3d2d7c-f5e5-11f0-b15e-2bf370ae4941 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=yyvFWv3+VBwTDB5ly/AP9wyGd+/7w/KDiK488McpzGROGreGOws/ELXAdwJvmh6v03k8QLewq+X/PQglv/rHY8tTmbYgP9D+KM5Ao2/zalvwASpORK2X52ROoECvgA4nGtcY9745Den6XuO3SpKxBnCZgiJANdYgrypiDS28BYGJmD3ZwPE3rOWfks94iUX2ijRJzEtpEX5Dq1LejmvRhxspU48RW66zh0hlBcZ4eV48JQkA7mdYEb/1mcUhRD4QfH9K3yDKAi3ExkCFkM8+BcGRz3ougucWdt5/eJRAUYOIvnqaIHlrHrkLKRfo2wVvQ81ORddDaCyTe4JG8UoxHA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=tlelRD0l8IWBcWpAH3Cc0918m2Klv7LDj+1fptSjsws=; b=JiIA6TSQ3fm68JLI7oqZLabjgvnVwgvTbEuCaT3i7cQM2XzPShXpBJAm9cdA1Xi2Jhnb0IfQ0QchUVlLVgbUnyQzutqFGCGv+mqbAjCtq+eTiNOiPrEMk7qi813eeVYPtLn5W7oljsA+Pl9SB2l3lKQCd/gXfq4XWVsB6XBTumy7tgUq9bNcB58aN87srxXvpdD5yX6nLl73Ykvf806Ckqaajz+c6grxZJV+WD0CZvRaldkwQkUUvpkdyBRblVzVERzUV6AkMayC1qQDrIcLuE4PTAd3jfCEsPusGhBRKnLPgVJ28EAwkPukeN48sCPxYha265mzxrVq8WIbDIQNWQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=lists.xenproject.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=tlelRD0l8IWBcWpAH3Cc0918m2Klv7LDj+1fptSjsws=; b=LdIfjEjEmXkhQHzcBU31sfI4YEi/dgN5enPulxU+GnKDVjarBcOeDxk4awEvwv3snMkkZCeidV/oFQUMwZMZ12Egr4LBLRWIVjxuVzFuusl+0wWNZfRqABR0Ydoaua2I/jOsg9GsVcLL3URaNZ+YM8HXfq9J0tuhQvoqzq2VZLw= X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=satlexmb07.amd.com; pr=C From: Alejandro Vallejo To: CC: Alejandro Vallejo , Jan Beulich , Andrew Cooper , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Jason Andryuk , Stefano Stabellini Subject: [PATCH 2/2] x86/svm: Intercept Bus Locks for HVM guests Date: Tue, 20 Jan 2026 10:53:50 +0100 Message-ID: <20260120095353.2778-3-alejandro.garciavallejo@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260120095353.2778-1-alejandro.garciavallejo@amd.com> References: <20260120095353.2778-1-alejandro.garciavallejo@amd.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: satlexmb08.amd.com (10.181.42.217) To satlexmb07.amd.com (10.181.42.216) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1PEPF000044F7:EE_|DS7PR12MB5814:EE_ X-MS-Office365-Filtering-Correlation-Id: 8120bafc-1136-43bb-938f-08de5809dd7b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|1800799024|376014|36860700013; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?5mlqNkf/jsJC5sNIfaNBfTddN9Fb1Qjukj0fw85pkvyBGbwRigOftA6grPK3?= =?us-ascii?Q?3xuFm+IB8QVUy73eXsVWkQsPci0QLPJlBjfJiQi/x7WgPuybhwdUoDpL/ErS?= =?us-ascii?Q?fNQux0cLt1XXomfY+yOKINb1dzZfwjcR14CN8YcQ7GPUlZH4ak4TIJ/SRz6o?= =?us-ascii?Q?qjBrs3E3U9JEXOyjREm41ufMb3N/rFcpjmvMADx+GLeuxAwRpaZo7YG//G8v?= =?us-ascii?Q?kJ8GtPPEEa5vzWeRr10w3wV/caF8IaVhQgUwCrDx1THPyEGDDNLnsCzHxPQb?= =?us-ascii?Q?G60UhX8UMHF3GaTczpPooR8OTSjscwMztVMVlgsUo92Ik1pWbeRrfIbm0+TJ?= =?us-ascii?Q?51+MMM5XLLpu2rt4zDklXCpDOUCi7zLkh8cGHI9fqgNUJhJu2hwkOJiPacVf?= =?us-ascii?Q?l9etZk9syRabUoLtcwVpidz3IAxXQ1V93DlrpRzxURKG88/+K6kStaZlXHEb?= =?us-ascii?Q?uNtktBaD/QgqcDZQalObZd30MTRlKJlwSIAPcZ2UWaL4prTr8x0WbOuMaok1?= =?us-ascii?Q?2RQbNxHoIo81ojof6eWgo9SN2mMPt+eR8Htmxs0CRFQDmDfN7W42pGPVBrX+?= =?us-ascii?Q?9EKoaKMz/5gtrHuRj77G33FT/JF6BBNDspL4kUMhuTru8JZE7zDUvtVpoDaO?= =?us-ascii?Q?q4fhGoOTD8/jw3Wrrwytbs/y3YytXSViZVv1SppWpLxBxDdN/D6CkblY965x?= =?us-ascii?Q?cbF6lj5Zt9rqL6leq1a25KfE+MMHkvqZUPlAtD9nfFrtFfzGdf5zIEekxk3p?= =?us-ascii?Q?BAUzZUcjE6qb6AklfzMVUiVnuWpba5UH2Xo7yy3cM872lVXziZAZdivDkJyG?= =?us-ascii?Q?my9OEQ3i/uGFsU0UkFI+Omk9JmiS7Y9Fkva5wegYdc8SFdcCpduTKLhVmzeW?= =?us-ascii?Q?1lyhnyvR7hCcu4KZCsxC37sOHviOPL8/sdLNThyP+sCYsm5r5XIDjMaKkwB3?= =?us-ascii?Q?cEpfuE2yBlqOETIyTpnUVEuFQ/VSWGVk9TK92CZmIr+gon6d55n8lT3iUITf?= =?us-ascii?Q?Q6d3wWITRLlgy+rMouzUmUH48goJJ/hAP0AfksV4pJnFFPD7+Nr/pP4AxqmO?= =?us-ascii?Q?npDvM9h3+BSTOCRlZNZuKPacsge4agKBp/kbyi7i1kBb7RPR/pAqXCjWzhg0?= =?us-ascii?Q?KNOT4TWNV/Ah1brO+wgD633hbC+NNZWF/FJ77Jr+WQ0TPjmfww+Wq8LDJW+R?= =?us-ascii?Q?Qr0CPibV7mXMUFPp0dijKY636exRDcBrTJuGNMinoMTMKbHn9XbGJmPTWs8r?= =?us-ascii?Q?FvDMlICe10ETRTVk4DKX8oi2uwSqalt2QAhF0h/v1XsDKudy6pHJCHJqEeia?= =?us-ascii?Q?vf2GXd30S+RrAhDgczwZzXfNVovxCSpa+4yaPRRjmSAZ8UnNR3IeXuCnKi0E?= =?us-ascii?Q?U/eIvnWwKINz1V/KOmByLIJHZ5eQlxt819paRB80BMpdZwAEfu5o+Xgc+DEl?= =?us-ascii?Q?/GiKrGYe9NysF6BY8eTFo0pQ5D9SM7Z776BTUQ3W4dks+tz++ADQx/LQx6z/?= =?us-ascii?Q?ly+j9pQev9BofVx/VfQsYX7RcmRs8mK647Vk+qsgUqu7jhbT7zhVQtQ2wtOM?= =?us-ascii?Q?+w63V2kwp6kUK81W3CPT9lTpp1Zb9g8u0Naw5o4PoAPB6cSK2fF1wmGRZFox?= =?us-ascii?Q?D2FMBCDVVG6L207hNTw9S1U=3D?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(82310400026)(1800799024)(376014)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jan 2026 09:54:12.5677 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8120bafc-1136-43bb-938f-08de5809dd7b X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CO1PEPF000044F7.namprd21.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB5814 X-ZohoMail-DKIM: pass (identity @amd.com) X-ZM-MESSAGEID: 1768902887131158500 Content-Type: text/plain; charset="utf-8" With the threshold initialised to 1 the guest exits at the first buslock. Initialising as zero is invalid and causes an immediate exit. Signed-off-by: Alejandro Vallejo --- xen/arch/x86/hvm/svm/svm.c | 4 ++++ xen/arch/x86/hvm/svm/vmcb.c | 6 ++++++ 2 files changed, 10 insertions(+) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index 9748df87d8..dbb7f99d5e 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -3087,6 +3087,10 @@ void asmlinkage svm_vmexit_handler(void) hvm_descriptor_access_intercept(0, 0, desc, write); break; } + case VMEXIT_BUSLOCK: + perfc_incr(buslock); + vmcb->bus_lock_thresh =3D 1; + break; =20 default: unexpected_exit_type: diff --git a/xen/arch/x86/hvm/svm/vmcb.c b/xen/arch/x86/hvm/svm/vmcb.c index cbee10d046..7a19b1ab61 100644 --- a/xen/arch/x86/hvm/svm/vmcb.c +++ b/xen/arch/x86/hvm/svm/vmcb.c @@ -66,6 +66,12 @@ static int construct_vmcb(struct vcpu *v) GENERAL2_INTERCEPT_XSETBV | GENERAL2_INTERCEPT_ICEBP | GENERAL2_INTERCEPT_RDPRU; =20 + if ( cpu_has_bus_lock_thresh ) + { + vmcb->_general3_intercepts =3D GENERAL3_INTERCEPT_BUS_LOCK_THRESH; + vmcb->bus_lock_thresh =3D 1; /* trigger immediately */ + } + /* Intercept all debug-register writes. */ vmcb->_dr_intercepts =3D ~0u; =20 --=20 2.43.0