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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 7106AE81BDA for ; Mon, 9 Feb 2026 15:35:43 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1225625.1532165 (Exim 4.92) (envelope-from ) id 1vpTIM-0002r2-N6; Mon, 09 Feb 2026 15:35:26 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1225625.1532165; Mon, 09 Feb 2026 15:35:26 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vpTIM-0002qv-KN; Mon, 09 Feb 2026 15:35:26 +0000 Received: by outflank-mailman (input) for mailman id 1225625; Mon, 09 Feb 2026 15:35:26 +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 1vpTIM-0002qp-8H for xen-devel@lists.xenproject.org; Mon, 09 Feb 2026 15:35:26 +0000 Received: from MW6PR02CU001.outbound.protection.outlook.com (mail-westus2azlp170120002.outbound.protection.outlook.com [2a01:111:f403:c007::2]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id f02a1dc2-05cc-11f1-b162-2bf370ae4941; Mon, 09 Feb 2026 16:35:20 +0100 (CET) Received: from BN9PR03CA0387.namprd03.prod.outlook.com (2603:10b6:408:f7::32) by PH7PR12MB7987.namprd12.prod.outlook.com (2603:10b6:510:27c::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9587.18; Mon, 9 Feb 2026 15:35:13 +0000 Received: from BN2PEPF000044A4.namprd02.prod.outlook.com (2603:10b6:408:f7:cafe::7d) by BN9PR03CA0387.outlook.office365.com (2603:10b6:408:f7::32) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9587.18 via Frontend Transport; Mon, 9 Feb 2026 15:34:43 +0000 Received: from satlexmb07.amd.com (165.204.84.17) by BN2PEPF000044A4.mail.protection.outlook.com (10.167.243.155) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9587.10 via Frontend Transport; Mon, 9 Feb 2026 15:35:12 +0000 Received: from localhost (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; Mon, 9 Feb 2026 09:35:11 -0600 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: f02a1dc2-05cc-11f1-b162-2bf370ae4941 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=f/Q14n78t+YsiK4DcB85dSUvRYoqSQgyZ6CYQs5PdLcSe1Ia+grMp+2iaxegQXoiLuanE1H+nAf0QI6YtaJ6r8SD42mT1aM0sAPo18HgEUcUU1Rg5eZz9XCLswoQ37Ou4R3a1YT9D8aqWSobJAC77Ql7Xz+bruyWGiztrnt4reyQyM0eve6nzMQyQXvhov9UuYulAgnXsTCEFA2N0xC5siO4uPLpeUXIsq6/2bqLTQcd4E8uUdumPENr8ibKm9nzLyUUlxqyhM7FYpB9q+cxY5ikrAdpndxsjuKlDNUJuz2hG2F18lXK1Pbdc7Z1+57241u9EQAgFihbG3Vk8eQDKQ== 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=98474JdQkV6HVWnwOuDmjpttYAaOW/uXN/Vxd1s/O5g=; b=vFg91qXN+KCbXjOp/DEeLRPf+KjhzoKPB6PXefGMU61QnfwqggUZpYAElVJWorRSbzZraDhp1yxqicBpQUuo5ZENGtbBC86hUh+EB8dpdJpt1Kq2xLBaOfRV+XF0PFAjyk7O+HSZj46AVbRm7BMZBo+E7kEFBVKIporIaB0I7NhgzlVa0giERJVrWSGAKotGElF0BvN/fV8HFY8DJaaNUA+KIkvjy8lgw2pAqgUTQ9ACU1gqwopyGFD2mPA7S1dt7wreohqQOVyAmYhfKzkfCqPdE5iHdUlHNCE8z6J6E4gmfuX+5AyizaeUcBndYUvunqrx6vr9xkR6Okoxi/ssAA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=citrix.com 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=98474JdQkV6HVWnwOuDmjpttYAaOW/uXN/Vxd1s/O5g=; b=PbH/W663rUMZArcZwbt1zp2FFfUcsKikc/pYnLW7miVNqJdSnlU0hsamOoaUhSbpXbP4844Pr5UfLYeuKcjnhoR7d7n3RiUUcbFAmnYMN4DFMlNEUnkjCWWn8Z/H3i5kRITe7e71uiSvs+46ENL9BIFP1XGu5kCJaR2MKOZtSvY= 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 (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 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" Date: Mon, 9 Feb 2026 16:35:04 +0100 Message-ID: From: Alejandro Vallejo To: =?utf-8?q?Roger_Pau_Monn=C3=A9?= CC: , Jan Beulich , Andrew Cooper , Tim Deegan Subject: Re: [PATCH] x86/shadow: Delete the none.c dummy file X-Mailer: aerc 0.20.1 References: <20260209104104.7840-1-alejandro.garciavallejo@amd.com> In-Reply-To: X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: satlexmb07.amd.com (10.181.42.216) To satlexmb07.amd.com (10.181.42.216) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN2PEPF000044A4:EE_|PH7PR12MB7987:EE_ X-MS-Office365-Filtering-Correlation-Id: cbadc5fe-5907-46c3-ff53-08de67f0d0c5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|36860700013|82310400026|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?S255aWh2S1F5cDdKa1E3Y25USXJpVHlGN1AxT25xMHdnQ2J6ckQ1R1R0ckda?= =?utf-8?B?SVlPQmV5RVl0YkV2cXM2SUs2aTZVNFRmRGxEMkgwOEVxcnEvbURzTDBudlJQ?= =?utf-8?B?Nk9BTk5ram5RZDZOUmhMbTBpRG5yNkFJVDJCazd6bmhkNWV3cjRCUU1MQ3F4?= =?utf-8?B?VEYwenlvTzZKRnVHUjZabWMrNFNxc2RLaUpjQWwrVEhWdjkrYndzMzhuL0ln?= =?utf-8?B?M241MHVmS1R6TW5hWHI3U21QMVRQQ0wrMFd1cExwMXpHNmdDcVJWTDB3d1Zv?= =?utf-8?B?T21zOThoVEFmRDBEWWpSeGh6N0hKZWdvaWNaQmsrWmhROVlDdG1EaEswV3dh?= =?utf-8?B?b2xHUDNnQ29KWEV1bVh6TUsxZHlFTzYwOEhvczFhQ3F4UmJpRUZrY2lEK2hO?= =?utf-8?B?ZmJrUnhzRFNuakZDc1hBOEp5ajEyaW85aERlaGkrRjV3NmJweS9CUzBab0Yv?= =?utf-8?B?KzVYMWovaVczMmtjOXZ2dzFKZXc5bmpsdGhITDMyMzVCK25vWjlWMzBKaURT?= =?utf-8?B?WGVYUzdYN2ZsZkVFeWNGVG56WCtvaDVZNU9PTFY0czFJOTIwazkxRi9pbnBz?= =?utf-8?B?Y09yR2ZjcjA1YkdjWW5kVmNxcjgyWGZLd1JnNlpRQkcyS2dzQWgzSzFaanJh?= =?utf-8?B?dE5HeExjR0xyNmZPZFdNTSs4b2Y4K3Q5akRlby9PaEo0bjU2UTZ2U3M0dGRS?= =?utf-8?B?aWdRM2xLclBqOG44dWxadGE3UStQZjhMejl2enF4ZVNUSFVHMXdBeDhRUFoz?= =?utf-8?B?UUxxRmh5dXljcFFTTWxRQUtrcUFocFJvQmhsbHYvSWFqRjlIbjkrdmZQM1Rs?= =?utf-8?B?YUlZMjU5SVdBMlQxQzBFNGpkeUw3aFBjWVg5S2UwWkRxRlNPM2diR1dTRk9F?= =?utf-8?B?YXJ6bmJiZm1lelM2ZG05blpTaDJLWjY1QTRxZ1BKR3BJYTdGUlk0UmI4Zy82?= =?utf-8?B?UmJqYTA2M2hKcVFYN2tLd1FGbkJZRitCd2dLZUpXaGZJTWFZOVRMTDRkb0I5?= =?utf-8?B?dUVnbnN3T0dPUjFHL2Ira2xyalYvVE1sWll4amc2amtBeEpyRTFjVlkwcEJl?= =?utf-8?B?QkZGR0c2dFppVlRXcnVld2oyR2hpcWZac1pQb1BGbkhqUytHTHlDQkROVGVW?= =?utf-8?B?QXduYmxiQUhMRWxTZllMZHByR0xHa2owdmsvQkk2VEk4enpydnlnNHB0d2Fp?= =?utf-8?B?T0MrL3E3dFZMZjIrbjFvc2ljM1QzU1lUbzBWaWV4NEQzQ2pMc2V4QzhZTGs4?= =?utf-8?B?L0hRMkdPZTVMZWQvMmZMdlRhTFBhYS9IbDU5LzgxMEdZRVNOdTc2emtNYUFB?= =?utf-8?B?cHlEOWVMSDJRaHVhVFUvT0JDNnBWeUJhRjdtTGZSdEVFYVk0N0xLM2h0YVhP?= =?utf-8?B?RVFKOHhuZVl1NDZ5SjdXZHlWdDV4NTZiUHRSQjgvV3NMZXVIeHJqckorZ3BV?= =?utf-8?B?VkRxQVNzNVpRdC9sSm5INU1tblBiQi9melRZeHF2UmYwbHhic3FiQk1BMG1N?= =?utf-8?B?S0RHWFFKWVRGalBtWFJieS9GeE5vaUVoWWFtSWU2ZXlkZm5oa0RDNTdMUllt?= =?utf-8?B?TlVjS1MycXBDaTkyb0R2NzExLzFHaDdIMnY5ZmRVUUVlbUJ0WGp2NFR3S082?= =?utf-8?B?enJtQ0dtVnRKcnFMVlR2RjZ4QktKQU8zbklyOHNoZzQ0ZFFLRG5XM3dWRWVq?= =?utf-8?B?UURTK09ZNjJmZkNzaDNBaE5laDM5Wmk0SEhaeTBYZGg5c04wSVUvTkpQTTlF?= =?utf-8?B?OUxxbjJmeFdsUWV4VXp2OG02bEdWZTFlWlZnSTV6dEpwNWQydkV0bVZDazBm?= =?utf-8?B?aGRKV3FIQzBzVDZhRllvcDBIV1N2TFVMbFUvUEZyY1VWMGVnS2VTVnlIQ003?= =?utf-8?B?a3A2RGVRUVJBQ2p5Z2RkaWx1Wlc0NGxwNkVXY0VVV2RFZmZlbWp6dFM0OWRx?= =?utf-8?B?UThudGc4cEdnUlJhR2U3SVgzNzBNd3VDSUQzbHRHRWhKQnRKQ2xzd09QakYx?= =?utf-8?B?bWx2QXJveFQzSVUvMXFXeUVLZkFJVnpNcU02V1V2NXcwaTFRQis0ci9kSENa?= =?utf-8?B?eWhkY05wUVFnWG5Dc2txdTJrNmJxKzUzeWZnaUJMM21aVlgyTUtqdmJ6cU5m?= =?utf-8?B?S29ramxxK3ZSZ05oNWNxbmRDRXZWQ3FvbWdkeTBOQzNGVE40Rm0wakZobmZF?= =?utf-8?B?K0JOTGFFLzV2NDMweWVnc2gwZFZZTUNhWlRFUmdsSTYwRVJvaHpNUEIwdm5P?= =?utf-8?Q?gnQuyCtDrdznvRwWrRExy2ULGFRaO1xdEZrGEsE89M=3D?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(36860700013)(82310400026)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 2c3msWI7kbslzs8l2VTZfvv++dKmxL2WsykYg0YleI3P5IyZnJpf5IaYToB8i/R8yHB7m8knaW6e+4CySPfdcqtZ2ppsAkfbtPms8ZBxSZKn+zm7+Go7vPacrc0B9Wt2eJe6RaM9YQ5BIP0t5STUZ+V3pu01y58HrDLG6eVggOrP91/CO32K3BxvcCALP6ZLm3PlNOvNSQmwBNiQTTkq7+Gd2XUVVC+Faw0cTLy49kW2L9KqnwKHAd7aNCIaoybl5t48GfG+pQ/At8In8eCXroSLxxXFAsrNDHkfqMEzs/gl+zmXR4UwkYeKqrw6OVwCuHCHlEXPvOsArtyWnefs/2DtLTamBGUE7r0J902m25xUf0SbF+WHSHDvSnZfn34fHg2Ocum5pWSzb5S3offxzxPBDlAhPznK/aFOEMRtpJ1nr9NgyvTPd4Jc3wkwvZfo X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Feb 2026 15:35:12.5196 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: cbadc5fe-5907-46c3-ff53-08de67f0d0c5 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: BN2PEPF000044A4.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7987 On Mon Feb 9, 2026 at 3:42 PM CET, Roger Pau Monn=C3=A9 wrote: > On Mon, Feb 09, 2026 at 11:41:02AM +0100, Alejandro Vallejo wrote: >> It only has 2 callers, both of which can be conditionally removed. >>=20 >> Signed-off-by: Alejandro Vallejo >> --- >> I'd be ok conditionalising the else branch on... >>=20 >> IS_ENABLED(CONFIG_SHADOW_PAGING )|| IS_ENABLED(CONFIG_LOG_DIRTY) >>=20 >> logdirty patch: https://lore.kernel.org/xen-devel/20260209103118.5885-1-= alejandro.garciavallejo@amd.com >>=20 >> ... to avoid the danger of stale pointers, with required changes elsewhe= re so >> none.c is only compiled out in that case. >>=20 >> I'm not sure how much it matters seeing how they are all unreachable. >> --- >> xen/arch/x86/mm/Makefile | 2 +- >> xen/arch/x86/mm/paging.c | 4 +- >> xen/arch/x86/mm/shadow/Makefile | 4 -- >> xen/arch/x86/mm/shadow/none.c | 77 --------------------------------- >> 4 files changed, 3 insertions(+), 84 deletions(-) >> delete mode 100644 xen/arch/x86/mm/shadow/none.c >>=20 >> diff --git a/xen/arch/x86/mm/Makefile b/xen/arch/x86/mm/Makefile >> index 960f6e8409..066c4caff3 100644 >> --- a/xen/arch/x86/mm/Makefile >> +++ b/xen/arch/x86/mm/Makefile >> @@ -1,4 +1,4 @@ >> -obj-y +=3D shadow/ >> +obj-$(CONFIG_SHADOW_PAGING) +=3D shadow/ >> obj-$(CONFIG_HVM) +=3D hap/ >> =20 >> obj-$(CONFIG_ALTP2M) +=3D altp2m.o >> diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c >> index 2396f81ad5..5f70254cec 100644 >> --- a/xen/arch/x86/mm/paging.c >> +++ b/xen/arch/x86/mm/paging.c >> @@ -634,7 +634,7 @@ int paging_domain_init(struct domain *d) >> */ >> if ( hap_enabled(d) ) >> hap_domain_init(d); >> - else >> + else if ( IS_ENABLED(CONFIG_SHADOW_PAGING) ) >> rc =3D shadow_domain_init(d); > > If you want to go this route you will need to set rc =3D -EOPNOTSUPP; > prior to the `if ... else if` on the HVM case. Maybe this instead else rc =3D IS_ENABLED(PV) ? shadow_domain_init(d) : -EOPNOTSUPP; And gate none.c on PV && !SHADOW_PAGING, which seems to be the only use. It's a lot easier to see the safety on the HVM-only case, particularly with= ... > is compiled out, and the toolstack has not specified the HAP flag at > domain creation you will end up with a domain that doesn't have the > paging operations initialized as paging_domain_init() would return 0 > with neither HAP nor shadow having been setup. That's likely to > trigger NULL pointer dereferences inside of Xen. > > Also, seeing the code in arch_sanitise_domain_config() we possibly > want to return an error at that point if toolstack attempts to create > an HVM guest without HAP enabled, and shadow is build time disabled. > I've sent a patch to that end. ... this patch you meantion. Thanks. I'm guessing it's still a hot potato in for non-shadow PV, which strongly h= ints at our being better off leaving it in that case. On HVM-only configurations= it seems rather silly. Cheers, Alejandro