From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH8PR06CU001.outbound.protection.outlook.com (mail-westus3azon11012005.outbound.protection.outlook.com [40.107.209.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6664C3845D9; Fri, 13 Mar 2026 09:12:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.209.5 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773393159; cv=fail; b=gdg/QnS5liYBJpLlN4CEf27R5XkhOnGlYu8HnTOPn3iOTIVy2grlvnp1tYryUW2kf8E86N4fCymzRV7NmNKBSNFFJ4is8TI0oZK7Ljt587DHGxAXVEGF6tPJn/t8YKc+6F1QJBAXUUe66e+kJWGzX+2ky7TOcD5LrohG1zOHPTo= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773393159; c=relaxed/simple; bh=CTpN+6nGP9+y5kSAXGe/sNfML67XhDwzQnnrD0O0H2A=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=XhDJ3PljIFDXSVoYrTf+/HaV+6IRvSEETsn+AksgUrTbWKGZiW6iXbTIXlRWLOeR6BpY5emC4pIX7ZjRJebUnJMb3uqA3CL8qYKakJt/xw8ZjVn8W7TEpU8OPYqsNndHgzU72esZFXRj21xnDErsMCoFDL3xjdS/VDc89BxQ2fw= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=xPgu1QuA; arc=fail smtp.client-ip=40.107.209.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="xPgu1QuA" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Sd5M/tLgOQu4hC7rpCR94zdLrXs2ga4P5RDmKZEE2p4L9Rjsj1Cdl2+gXBzsBBbYvBXwRgizXx3CINhX4myY6AQ/4ZePHfS4z8hONiAWY5/d4tJDjKlb4gUE0RrxaMSaCrQxzWPUik40pC1JvdKXPIS3sJ9l3hjXTCE3Umtp6+XwRk4byXsd3bgvv2LyQREbTGP5hTH67LqTPDHbaf5aoxzej+QewpMUeLGG7AH/rWdogmYpbObFKdYRUi26C2EZsh+GwXDVmthZjNqU554x42R0wL63Lo2jOJyUo0351td11cSXJTbmpetXSQamzU264LDGuIwkm2urj5UsYWSQ0A== 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=d5WBmDWQBoUIJW2AbV/HHiBC9zdE9Ww/ThAWmlWoezY=; b=FIhYkhnawg38FRLgIeNNXRZVDbPKY4VlrcrdT0/EyWMWhxzJps++XMZ+rhly4IvcbuwVaOn3O/7Ke3Zdh13nKIwp4/DFeVHprw+r7HhVSP8HHTfgQ9gSBKusEkbnoBWR2lG4lwM/hX9Bok2PsSZZ2bPVe/7Z1/n8f5BXrB9d4wPo59584LYDEhxxvqyFGh6oSpDrMQNQQ/XCWoaV9rVDG2aad7rBEGBmA7QHEleWTt3WpAr2kPY2NK42G3hX3AxuMMbvCQNpBg0mg6Tfc507haqSikY0FXF39nCeLVDi5qsgncuaIdbpQlDb14ySoixzbdVm8MapTuJQ3sL2PSs3HA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none 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=d5WBmDWQBoUIJW2AbV/HHiBC9zdE9Ww/ThAWmlWoezY=; b=xPgu1QuAyUnM3oR+OJimgy+hBvDlsJa/rlUPWeKkh5JsM3AjPMe2UF+v5CRr8KJrkkTl0iKI9aIEfYAFzP/8l1NzkO/6vPPRDeN8flO3IVgUvvE9M8EAkCl05o07VZkKp08LpLtKjqpPY33jGVyyScQxiIaSu5xVvWaJicp/520= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) by LV8PR12MB9358.namprd12.prod.outlook.com (2603:10b6:408:201::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9723.6; Fri, 13 Mar 2026 09:12:31 +0000 Received: from PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::ce69:cfae:774d:a65c]) by PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::ce69:cfae:774d:a65c%5]) with mapi id 15.20.9723.004; Fri, 13 Mar 2026 09:12:31 +0000 Message-ID: <50de8376-d675-4a98-9a86-8485dba5d449@amd.com> Date: Fri, 13 Mar 2026 10:12:23 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [RFC v2 PATCH 06/10] vfio/pci: Remove vfio_pci_zap_bars() To: Matt Evans , Alex Williamson , Leon Romanovsky , Jason Gunthorpe , Alex Mastro , Mahmoud Adam , David Matlack Cc: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Sumit Semwal , Kevin Tian , Ankit Agrawal , Pranjal Shrivastava , Alistair Popple , Vivek Kasireddy , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kvm@vger.kernel.org References: <20260312184613.3710705-1-mattev@meta.com> <20260312184613.3710705-7-mattev@meta.com> Content-Language: en-US From: =?UTF-8?Q?Christian_K=C3=B6nig?= In-Reply-To: <20260312184613.3710705-7-mattev@meta.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR2P281CA0116.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:9d::9) To PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR12MB5685:EE_|LV8PR12MB9358:EE_ X-MS-Office365-Filtering-Correlation-Id: ee3282fc-bd55-4c6a-d5b7-08de80e0a7dd X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|1800799024|366016|376014|7053199007|56012099003|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: QDeC4Dgqa7wXbTdSnWlSphQhJvczMprAh5vJ5OvcO71HP44EsvA+uy/lhoJx/JuDGJos2bLbq1qSKt4Sw8LjA83Vn7e8jofzZmKzonQJpTTMCQzJZekqmDHluelyj8nsE90lc0YmDPrUUvyUwZ4FbGqGywFJxHIMbRukLDwmnhxTNVjcsUSQqiBczK+BYmqaU0K3nNlNDMfAUKrtMsLyGZsWOjiyk6rfspDAXr/ehaj3KKeJKDi+wL/rGVRUOkKiI5AMBukC1qsKVy2Djq0nL2fSXOPkvqaeTrRzDqf7Vm36/zOC611FxtjrDsjBf9yjWW+ZY6EkIKhqLs7HFhPxvhAKn0FVcfn9D/3t2POwjoNwyu3IqSOcp6EjQG+355sALyjWjQu4nfaGY9ujsqDxkqu61668TYUPUm+Kv80n9LEbBB/iuw5hqtVG4AWz5gZKmx1gC4cBJXhnBfBE5n9aamTm0XCdEUs8+ksJ6VP0mQFzbvX0DuEA0O3+K9JMvNPbaRh06DJqxXCmROfcYdBAWMHTtQ7HiYjpF91wyDS0F5PP/MMElScuaVmkh6GsgYz5U1Y9+W8Qd9tHOtRdKxzdLM+hVKKEjcg7SJ6C1CfkcPVDcQ1LUdFDN37g219qf8DK+FiXU3m7I1b003pR8fh7yWc2C/ML++482BE933B+ap6lCMmXmudL7KggaJ3bwcbgSSwiNmdhCFvbcGGodyfeNFyNrux5O5ZDqbGhvwJU+I4= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH7PR12MB5685.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(1800799024)(366016)(376014)(7053199007)(56012099003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NlE3QVViblQ0SG1qZWVxMW82eXRGbEZaTzI3NFFqSERpcWxrRkUrVE42SlFI?= =?utf-8?B?WU5hWnVjeVBYN2Z6ZjlESlRtaHUzSVlGdjdEMVpYdXV2dFdQWEZSVmw2ZlZI?= =?utf-8?B?Q3daYlNXc2cybXhGOXR4NldyN2xabEVvUlBZNkVCYVFGU0FjcFZLa1A5b3ZV?= =?utf-8?B?NTFkYXgxVTZDc214Y3dORERDeTRKYTVmRE1vajBuRkl6MSs3NUMzR3NXY2pO?= =?utf-8?B?QTFsZHBkTUIrcUhDTE1DVGdPTnU0L3ZjM1ppRlVOS1d3U0tBc3JaOHpuV0lT?= =?utf-8?B?d05Eb3VudEtOV2lMOHluMFBnZ3I1aEtpODhJUnNYSVJhNTZySFpWcjY4eFdU?= =?utf-8?B?NlhXWkJ0SVVFaHZWMWpybnZZSXp4Uk1zMUNPd0N4UEFGYmpzL0FYWUpXck9l?= =?utf-8?B?cUV4R1ZUbm5sbXEzTXJZWHZ0NS9ZdnNJWVAvMUZQbFlET1Byc0ZhZWVQMUxZ?= =?utf-8?B?Wjh6aGYyTUFYOGppRVhVcWJ3MFRxdlRGbFJxVHhmM0R2S0NKVkg3bStPV2NH?= =?utf-8?B?M01GcFJQNEkxRU9NeTMyT2lJVVNiZ2VkYi83WEM5bUY0NU5Wd1JhUG4rOUFm?= =?utf-8?B?OFBrTnJ1SUVpRDJzS2lDU2NqYzk5ZUtheWxyZzRKalZERjh2UzFtWjd1WjZ5?= =?utf-8?B?UWpWc0crTXkrOFRtUVBDakJNTzJqRkMxRHFLTHpreTJyVmN5VlhhcndUYjM3?= =?utf-8?B?eFd3R1hDdXZoKzE4ZVh2L2dCU0FlbU1LNjM0MUMrdUJWSkJ5MzRIU2h6UllT?= =?utf-8?B?QWtXZ1FveU5GeURtY2VzUTdXYnVNMUo4ajYzQ0daZk0rNGhzNWxHamZrYm5P?= =?utf-8?B?R3AzZFVIZzF3b0lYZ1RGRG96enZBVE1QcXZjdGx1bUdYb0pDRHN2WHhXWFBJ?= =?utf-8?B?c3JNYitJbDUrbUpIQVFIMURiZTBRMzdHcm5abVFINjRkNS9HN2piZ3JtMG9X?= =?utf-8?B?L1NFb2V0dHdRSHhBYWdtTWJLNjV5ekRaMGcwS2FRVG9DUUF6ZFBVSW4vcldi?= =?utf-8?B?NzdrbzRkamNtMyszNXdVZEVkMFpKbTlLN3J4aHBEWUMzZndJYk8rdG9iRXVN?= =?utf-8?B?ZXloME1NOUNmR2RSTjJzSGFjUi8xTURKRDhyN3FSK25oUGlOUHJrODRWY1A0?= =?utf-8?B?cG1SK2xuek9FMHVEWklWU1lDUjJHRG8rTXFTbXF6eHNEa0UzczJERFgxd3VP?= =?utf-8?B?TXI3TWEvdysybVdWNmNJaXM1OGxZUFpOb3JPdDc5L0ZuaHZxZWFPUzFYNXdN?= =?utf-8?B?NTdGZlUvZzlTR0tTbDlLQy9GdUgzcGNWZjR3NmovN2FIbnFlY0tEdkExSUVs?= =?utf-8?B?MTl3S2dhS0VINGh5MHMyb0s0cm1iMzZNd2VGS0FCYUlBdmk5L2hibjVNN0dE?= =?utf-8?B?V1NSNXc4c2tzUnNESHpIREQxMS96VitPa0FoRHVvZ3Qxdnh2UFcxOStlakZr?= =?utf-8?B?ZUI2Z2d0TEhndnJ3bStTY055d3lEc2FpOWVEcTBlSERiYXU0NDkyUEthaEpF?= =?utf-8?B?dE5CNUhzYXhJQ1ZJSVVTaFZwaFRjelFwbytpQzc2SE1pKytKYXlyOE1YNUZ4?= =?utf-8?B?dm94SnROb2Nka0pOeU9WVWpuQWN3Z2xuejkwTndVbFFMaU5ta0dNdWJ0N3J0?= =?utf-8?B?QWlaOGduQm1nSE5IZGtnWGJKYTdlRGZibGp5UWs0M3llRVB5TkwxOHNXbDhR?= =?utf-8?B?MWhUL1JJZ1liSS9kMGt2UXhDYzRmNWFVQXVDM25IMXhZLzFQZ3VVbmpjeUNI?= =?utf-8?B?cjBzTHZhNlg4MzUrSjA3WXhzR2xqL3I5TG1rYlpSNjgyb1pTd0RBQlh0cktz?= =?utf-8?B?ZDFlMmdFWDRvY1dONmIxeGgyZHRQY0tmcWc1WXdrOWZVL2NiakVaNmpNYXgv?= =?utf-8?B?WDB4d0RDYzk2OFdVVkV6alZsdWhqODJRVG0vL0NrbjllNGNWZ2I4UDhiTGlW?= =?utf-8?B?cFZPU1lHNnFSVVpJVThOMDlCc1dEU3l4Sk1nRnd5d3pzQldZRWJSV2ZiR1Nm?= =?utf-8?B?Q0g1cVdVRHMvZ3dDb2lyZlZCSWdGQjZFNzdNaTFXOFhrVVlMUERNL1k3d3FQ?= =?utf-8?B?VFhiWFY5SVZiQ1dmSGRIcnFoaHhweVduUkgyek9Ob2pIZjhvV0o4U3NrUXQv?= =?utf-8?B?dW1NMkZPQmZNMjdpVlpEMG9TemhOWmxQQkJWa2ljWWM4YmFYZXJwaW42RkxW?= =?utf-8?B?enNkTERYb2VLWmJvMzM1UStiRXJDTW9vOFhEZDhDTFRmM2Rlb0pQcWlMOWxN?= =?utf-8?B?ejlMS0FMamlrVGZvV3lqbTJpTjRVUUUzbnFLNUxpMXJvaE1yajhyUlZFSkFn?= =?utf-8?Q?1UvfAFYSvn6KpdJ/qM?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: ee3282fc-bd55-4c6a-d5b7-08de80e0a7dd X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5685.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Mar 2026 09:12:31.3165 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: pz/N2nUrJ0CaHe5BbMmM47YiRLLvmZt/1kbdFahgj2ApZDkVhSzwm9pGhQv1MPJF X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV8PR12MB9358 On 3/12/26 19:46, Matt Evans wrote: > vfio_pci_zap_bars() and the wrapper > vfio_pci_zap_and_down_write_memory_lock() are redundant as of > "vfio/pci: Convert BAR mmap() to use a DMABUF". The DMABUFs used for > BAR mappings already zap PTEs via the existing > vfio_pci_dma_buf_move(), which notifies changes to the BAR space > (e.g. around reset). > > Remove the old functions, and the various points needing to zap BARs > become slightly cleaner. No a full review, but it looks like you now take the DMA buf reservation lock while holding vdev->memory_lock. I strongly recommend enabling lockdep while testing that, just to be on the sure side that all locks are taken in a consistend order. Regards, Christian. > > Signed-off-by: Matt Evans > --- > drivers/vfio/pci/vfio_pci_config.c | 18 ++++++------------ > drivers/vfio/pci/vfio_pci_core.c | 30 +++++++----------------------- > drivers/vfio/pci/vfio_pci_priv.h | 1 - > 3 files changed, 13 insertions(+), 36 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c > index b4e39253f98d..c7ed28be1104 100644 > --- a/drivers/vfio/pci/vfio_pci_config.c > +++ b/drivers/vfio/pci/vfio_pci_config.c > @@ -590,12 +590,9 @@ static int vfio_basic_config_write(struct vfio_pci_core_device *vdev, int pos, > virt_mem = !!(le16_to_cpu(*virt_cmd) & PCI_COMMAND_MEMORY); > new_mem = !!(new_cmd & PCI_COMMAND_MEMORY); > > - if (!new_mem) { > - vfio_pci_zap_and_down_write_memory_lock(vdev); > + down_write(&vdev->memory_lock); > + if (!new_mem) > vfio_pci_dma_buf_move(vdev, true); > - } else { > - down_write(&vdev->memory_lock); > - } > > /* > * If the user is writing mem/io enable (new_mem/io) and we > @@ -712,12 +709,9 @@ static int __init init_pci_cap_basic_perm(struct perm_bits *perm) > static void vfio_lock_and_set_power_state(struct vfio_pci_core_device *vdev, > pci_power_t state) > { > - if (state >= PCI_D3hot) { > - vfio_pci_zap_and_down_write_memory_lock(vdev); > + down_write(&vdev->memory_lock); > + if (state >= PCI_D3hot) > vfio_pci_dma_buf_move(vdev, true); > - } else { > - down_write(&vdev->memory_lock); > - } > > vfio_pci_set_power_state(vdev, state); > if (__vfio_pci_memory_enabled(vdev)) > @@ -908,7 +902,7 @@ static int vfio_exp_config_write(struct vfio_pci_core_device *vdev, int pos, > &cap); > > if (!ret && (cap & PCI_EXP_DEVCAP_FLR)) { > - vfio_pci_zap_and_down_write_memory_lock(vdev); > + down_write(&vdev->memory_lock); > vfio_pci_dma_buf_move(vdev, true); > pci_try_reset_function(vdev->pdev); > if (__vfio_pci_memory_enabled(vdev)) > @@ -993,7 +987,7 @@ static int vfio_af_config_write(struct vfio_pci_core_device *vdev, int pos, > &cap); > > if (!ret && (cap & PCI_AF_CAP_FLR) && (cap & PCI_AF_CAP_TP)) { > - vfio_pci_zap_and_down_write_memory_lock(vdev); > + down_write(&vdev->memory_lock); > vfio_pci_dma_buf_move(vdev, true); > pci_try_reset_function(vdev->pdev); > if (__vfio_pci_memory_enabled(vdev)) > diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c > index 41224efa58d8..9e9ad97c2f7f 100644 > --- a/drivers/vfio/pci/vfio_pci_core.c > +++ b/drivers/vfio/pci/vfio_pci_core.c > @@ -319,7 +319,7 @@ static int vfio_pci_runtime_pm_entry(struct vfio_pci_core_device *vdev, > * The vdev power related flags are protected with 'memory_lock' > * semaphore. > */ > - vfio_pci_zap_and_down_write_memory_lock(vdev); > + down_write(&vdev->memory_lock); > vfio_pci_dma_buf_move(vdev, true); > > if (vdev->pm_runtime_engaged) { > @@ -1229,7 +1229,7 @@ static int vfio_pci_ioctl_reset(struct vfio_pci_core_device *vdev, > if (!vdev->reset_works) > return -EINVAL; > > - vfio_pci_zap_and_down_write_memory_lock(vdev); > + down_write(&vdev->memory_lock); > > /* > * This function can be invoked while the power state is non-D0. If > @@ -1613,22 +1613,6 @@ ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *bu > } > EXPORT_SYMBOL_GPL(vfio_pci_core_write); > > -static void vfio_pci_zap_bars(struct vfio_pci_core_device *vdev) > -{ > - struct vfio_device *core_vdev = &vdev->vdev; > - loff_t start = VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_BAR0_REGION_INDEX); > - loff_t end = VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_ROM_REGION_INDEX); > - loff_t len = end - start; > - > - unmap_mapping_range(core_vdev->inode->i_mapping, start, len, true); > -} > - > -void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_core_device *vdev) > -{ > - down_write(&vdev->memory_lock); > - vfio_pci_zap_bars(vdev); > -} > - > u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_core_device *vdev) > { > u16 cmd; > @@ -2487,10 +2471,11 @@ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set, > } > > /* > - * Take the memory write lock for each device and zap BAR > - * mappings to prevent the user accessing the device while in > - * reset. Locking multiple devices is prone to deadlock, > - * runaway and unwind if we hit contention. > + * Take the memory write lock for each device and > + * revoke all DMABUFs, which will prevent any access > + * to the device while in reset. Locking multiple > + * devices is prone to deadlock, runaway and unwind if > + * we hit contention. > */ > if (!down_write_trylock(&vdev->memory_lock)) { > ret = -EBUSY; > @@ -2498,7 +2483,6 @@ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set, > } > > vfio_pci_dma_buf_move(vdev, true); > - vfio_pci_zap_bars(vdev); > } > > if (!list_entry_is_head(vdev, > diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h > index 37ece9b4b5bd..e201c96bbb14 100644 > --- a/drivers/vfio/pci/vfio_pci_priv.h > +++ b/drivers/vfio/pci/vfio_pci_priv.h > @@ -78,7 +78,6 @@ void vfio_config_free(struct vfio_pci_core_device *vdev); > int vfio_pci_set_power_state(struct vfio_pci_core_device *vdev, > pci_power_t state); > > -void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_core_device *vdev); > u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_core_device *vdev); > void vfio_pci_memory_unlock_and_restore(struct vfio_pci_core_device *vdev, > u16 cmd);