Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.38 as permitted sender) client-ip=23.128.96.38;
Date:   Mon, 4 Dec 2023 14:36:03 -0400
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Yan Zhao <yan.y.zhao@intel.com>
Cc:     iommu@lists.linux.dev, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, alex.williamson@redhat.com,
        pbonzini@redhat.com, seanjc@google.com, joro@8bytes.org,
        will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com,
        baolu.lu@linux.intel.com, dwmw2@infradead.org, yi.l.liu@intel.com
Subject: Re: [RFC PATCH 16/42] iommufd: Enable device feature IOPF during
 device attachment to KVM HWPT
Message-ID: <20231204183603.GN1493156@nvidia.com>
References: <20231202091211.13376-1-yan.y.zhao@intel.com>
 <20231202092311.14392-1-yan.y.zhao@intel.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20231202092311.14392-1-yan.y.zhao@intel.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Arj2jwTItPyBpFshOQAe/tUKGWR6ymy6BGp4mhiFKTK65uRhZLdM1cHdtjcB?=
 =?us-ascii?Q?ofw9jDeoYy3g8TWM+L4/nZcF+h4B6ZnNdHCRvKbXIC23QsNGW+dzuqS9KYTV?=
 =?us-ascii?Q?Y8qbbpgsooI5nW97RAMhnmwgobCsuliz9RK+lIBBknhEyTOCH5gPwnRsoGon?=
 =?us-ascii?Q?phLp2ix1mlwV0vh+0C7EOlnNHwqcSISxr8q6O26og/Hk/ECSfss2kZFtv/tk?=
 =?us-ascii?Q?7uksJ7CuSsN5bF/0deDf0JrU5mMsyBKNwUut6nJEZaYzBk3BnugMEirBXvDt?=
 =?us-ascii?Q?vloPOM+KHyAlbMyP0RvwtWq/xzLggsN/LYaxh/Ziy5kur8I5YsXtmC2k6r6c?=
 =?us-ascii?Q?wUwjVBkwlvzRa1Z1zIDIa4qXWDTOsYzNnNwGtZWgptGqv4qpyotUifLyFj08?=
 =?us-ascii?Q?goyP1zA/VFAZwcyHYVhePkn4Tdwfd3f0OBCt4yvNuQolcdv1DjEtvZ2CK3wP?=
 =?us-ascii?Q?ZdDTBVlKE+w5cqnxSRWJrrDX7llJ0OMV/ruAXEMGgoI79dtoEZXJtHwNL9aI?=
 =?us-ascii?Q?IBVNkZ3cUEYl0oBbxS+ipaw+XUaEYW658U+JyFyYwdchyEYQvG3Xnzr/BzST?=
 =?us-ascii?Q?9YsHzBn5pI1QkMaMj5lx9f3/GSPC+wXv+esrwNXFdiO9buj1irUD5rhRuKo6?=
 =?us-ascii?Q?LXLDEcOH+P+iIIo6k056bzBaNrDNJIIgfQEoHdTR88PYIBtViLuHEvO9WWMC?=
 =?us-ascii?Q?aN8l0N0tgGdX1A+mj9VmWL0Jv9XDAIeSb2CjVl1K0++JQyCsxX6DgQGjkxNg?=
 =?us-ascii?Q?FLuLCfWYKYSopqoBvt+cFPboVlq8QHGMZJKU+7X0Arhh2xbbdy+p3kjGBOtv?=
 =?us-ascii?Q?9JAB6BLLxRMDdIxDYcp0eDZkkcH/dcTFICSCzS/2M5wlm8ELmKABRUMcNCnc?=
 =?us-ascii?Q?DSJd3d2M9bBUcM7eS6gA9cHqu/xnbqQ5WxcZYm6CflvW2pCYakRtkBloV1OG?=
 =?us-ascii?Q?VRfqo9HzOejASJp6+26am/PoqgUjWAeV2ZllaUQPLzG2zpC/jAjsqsb8JD47?=
 =?us-ascii?Q?wLvuj2ZWcGSfjXoxgcsmNqfbS076DOR894GbGxEGPrgGClxP+ICVKcGllJ0f?=
 =?us-ascii?Q?if9aHqZx5QeyjTvk+/zegSLJXfsnWu4JTQZiUJtbcimnB4Q0f/E7uGRcAKke?=
 =?us-ascii?Q?BFLjJIkeUYbKsMehTxAdLIbtqhVA8B9NAZZhChqxX2ir4f/mMQxEw0CWAszl?=
 =?us-ascii?Q?VEY6i5Pr40QAS1LIXLcZDEQK+qaBRAk2NIfh8UgWAvPvhcR/Wd91hnAfSN5c?=
 =?us-ascii?Q?S4s1WtWjuTWbNyAIxYPgAasuJT5wXav4IQkNRb9lgDCozoeKy/O4yaLbthzq?=
 =?us-ascii?Q?onvd/k7C0dIjQX69Btf5gN+Hrqq/foH/L8zTnxpHqpD0EXJ+FLmTcuBdEJ+1?=
 =?us-ascii?Q?HBHoE1/LGru0oDrYhA9Ga/eDB0Z4cMEpoH5+Oe04MeitAZ9ZhLFBT1b3FS8p?=
 =?us-ascii?Q?s2S0Sfn3QkmrSXFkwfE/Ue1Exv/FeTo7yIYwkWHlpYWwHjcGpZNQnD+NwIIw?=
 =?us-ascii?Q?6/PdUFuiCd7ffPUakbYo6BHLPuiiBSNn8UmbKXeQjcwtv3UdC39bQSCcA/5q?=
 =?us-ascii?Q?e6wH2dLAMobM7rzX+3a08Uq/0MA47K8sgFaQM6lk?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: ab329631-4c02-413f-40df-08dbf4f7df2d
X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Dec 2023 18:36:04.2766
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: xrdMLkCUXlEMDzz+PykNVxyTRo1fyF0insF3eRRHZhECTO/U1CJfpeaTEZU1Fh3w
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7889
X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on fry.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (fry.vger.email [0.0.0.0]); Mon, 04 Dec 2023 10:36:19 -0800 (PST)

On Sat, Dec 02, 2023 at 05:23:11PM +0800, Yan Zhao wrote:
> Enable device feature IOPF during device attachment to KVM HWPT and abort
> the attachment if feature enabling is failed.
> 
> "pin" is not done by KVM HWPT. If VMM wants to create KVM HWPT, it must
> know that all devices attached to this HWPT support IOPF so that pin-all
> is skipped.
> 
> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
> ---
>  drivers/iommu/iommufd/device.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
> index 83af6b7e2784b..4ea447e052ce1 100644
> --- a/drivers/iommu/iommufd/device.c
> +++ b/drivers/iommu/iommufd/device.c
> @@ -381,10 +381,26 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
>  			goto err_unresv;
>  		idev->igroup->hwpt = hwpt;
>  	}
> +	if (hwpt_is_kvm(hwpt)) {
> +		/*
> +		 * Feature IOPF requires ats is enabled which is true only
> +		 * after device is attached to iommu domain.
> +		 * So enable dev feature IOPF after iommu_attach_group().
> +		 * -EBUSY will be returned if feature IOPF is already on.
> +		 */
> +		rc = iommu_dev_enable_feature(idev->dev, IOMMU_DEV_FEAT_IOPF);
> +		if (rc && rc != -EBUSY)
> +			goto err_detach;

I would like to remove IOMMU_DEV_FEAT_IOPF completely please

Jason