Message-ID: <d00b97ed-2d25-c58b-f844-be4f4f159335@intel.com>
Date:   Wed, 8 Mar 2023 19:51:36 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Firefox/91.0 Thunderbird/91.11.0
Subject: Re: [PATCH v2 1/5] dmaengine: idxd: Add enable/disable device IOPF
 feature
Content-Language: en-US
To:     Lu Baolu <baolu.lu@linux.intel.com>, <iommu@lists.linux.dev>,
        <dmaengine@vger.kernel.org>
CC:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        "Robin Murphy" <robin.murphy@arm.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        <linux-kernel@vger.kernel.org>
References: <20230309025639.26109-1-baolu.lu@linux.intel.com>
 <20230309025639.26109-2-baolu.lu@linux.intel.com>
From:   Fenghua Yu <fenghua.yu@intel.com>
In-Reply-To: <20230309025639.26109-2-baolu.lu@linux.intel.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?M0tvWEJwclluZ0NaOXNiK0RlRG5JK0Nvc2UzT09TRGM3QnBxV0xLYlczVDQz?=
 =?utf-8?B?WDloR3RPK2tNa25ZRWZWbkhQZWRlZXFkMStPZ3lnKytMeFVieTJhUDBHWTM4?=
 =?utf-8?B?V3JIQjhXeS85UFYvOVlLUmdTbU1WK0FTQkFxdHNOcXMya2dCcXAyQ05FZXNF?=
 =?utf-8?B?enVrZmk1elZMOGpONHBvVEFLMEZRWjJ3S2tSREpTemo2c3FvWXJjcmFhZHFt?=
 =?utf-8?B?TjVUdzBJdWh1MWZzWUcvbzNqSzRJaERQNllQSGhnZ0FsamtLSVkvT3ZXNkNn?=
 =?utf-8?B?ak0yUkw1UXBub1pXWGwxMGpXVFc2YUZ3SHgzOTY5TUxMdnBKU21SOXlQWUQr?=
 =?utf-8?B?UXJTTGExekFRUWNUclJHalRkRHFrNWVCb2xiTzNvd2sxUTJGT1J5SitCbE9J?=
 =?utf-8?B?ZVc5cTUzemZ3Z3N2Z1NLbFkyZXFnQ3dyOTBmTGVXNEdtWDJnUUo3NGI2YXdr?=
 =?utf-8?B?K05jMW00MXJ3SWVXbnlIRFZrRUc5M2NVZUVZQng4aG9wclhVZURSUFpMcVg2?=
 =?utf-8?B?UW5YOFBTcDBRTCtITSs3c3AzcDNEMURvMmRNQlJsSFE5SHNJV3RjZ2FaVUdK?=
 =?utf-8?B?eTRJOEtvZS9sTDRmU0xWRWhWNHNiN2RWWFR6ekJZRTRvU21McU9ra0NraWRt?=
 =?utf-8?B?aWVIWmJ0VCtKaXJ5cjAzMkUyUjJvN3ltMWZMaTlxZldrYXJCcEU3WHhZSUhq?=
 =?utf-8?B?ZFRUZC80dGUzMERIU3BUMURsY0VBaFZTQmFDWTVRbEhhZnBOTnRPRXZOWm5N?=
 =?utf-8?B?YTM1MHA0NnJkem10Z2FidFRISGpPSW8rM0w3OVFRZHMxbkhBWmczQTdZY3B6?=
 =?utf-8?B?SzhpSEFFd3JSNFlONWtocVBWY0tlWUR5VVJxdC9WUVRYK0NXeWovUXY5SC9D?=
 =?utf-8?B?dGtxOVdKN05RVlVxZ25xSnhhdUQ4YkZxRk8wbEJ4bStvUndXWDQyL0pOZ1hL?=
 =?utf-8?B?YVpLYStEOTVYaWNrS3luTWVoUzY0V2hzSUpwdVNmT3o3YUtkUng5ZjVJN2pL?=
 =?utf-8?B?VytmMEtmTERRMzhMc3dpRGtYUkJoc3NhNFE4OE1PMkovK05tSEo2Y0NwdGM0?=
 =?utf-8?B?Ui93SGRyMWc0VWh2L1diYlEwMUpFN1hNNW9WaXBQNCs5YVBWT0hsa0k2WW5p?=
 =?utf-8?B?eGpRd0ZDUmwyZUpJcVFwZ0lsV0RkS25wWXh5UVpqTEY0SitsV2JXM2h2c2Jo?=
 =?utf-8?B?SjhYRjgrQUZIdzhUYzlRZXJlNzJYakIrSTEzSHVDUmtBVmltMFljRjh2eFB0?=
 =?utf-8?B?VnlBR0Fvai93aUxUNW5HQmhteGorcllBbFNLdFNQRXdCQWtzQkc0UVJVVnRS?=
 =?utf-8?B?alZBc0VHeHhHMVloR0xQQXNJNC9ueFVmRjR2bzhVZDJwVWhsbU5qZzhMOEVw?=
 =?utf-8?B?am5iYURMQm4vUkVvbzR1ZE0xOTZaRlRUcFlWMTNiWUpkS1o3bjdHVU5abjkx?=
 =?utf-8?B?UHUweWhLMWFlaG9UL0xzL0hHWGVXTHc1MHRLYWJ5bGtSbXJOWkt3a05qZnhX?=
 =?utf-8?B?M3Q2TVc3UzZIMzB6Wm4xclRHVXU2c1pFdzU1OUVEM21pZEl3K0ExUDU2cnVj?=
 =?utf-8?B?WURhUjRPOTV6UDRyTFo3Szlrd3ZjcWllMnBZaXIyLzVqc2FJMWE2K242ajZj?=
 =?utf-8?B?ZmhWdXBwOEl3VVdDNUlmUjI3MXUzUE9GMkkvZ01tTzNBQjkxdW5YZ3pjVXZF?=
 =?utf-8?B?OXRTdk5WLzZQTkV2OTdRU1MycUhSN3VFTGRheWM3SjZxNTdSOGI2UFZDcTQr?=
 =?utf-8?B?anJyMFRXdXZ4V3I4ZGUxN1diL1Z6U0g5VkZIRVo1VHU3c0Z3RUdRTUpVcW04?=
 =?utf-8?B?d05Jc1YwNEkydWRVYm5zYXBJeEFwR2dYR0lnMTFsTEE1THJoRitKalZmRzMy?=
 =?utf-8?B?dXNsYkNSRFRvRkdxZmVGWllwcnZWR1hNTlkvbmNvMTdJb2tCVXQ0M1RpVnVa?=
 =?utf-8?B?eS9tbytCYzRkdklHYWVWS0UyMm9GcjNXb1F5bDRLRXhiR2tLZjdHWnhkQk1O?=
 =?utf-8?B?MlRkUm5rajc3UldFYzJxdWorUlpob3Q5OG9xOTlBY2xQeCs1Slh0U3FDWGNU?=
 =?utf-8?B?cjNTbXlRNm1WeDNRQUptb2wzRE5ILzA1MXk2MmNiQzFNUmdmRGlxYzVpdnl2?=
 =?utf-8?Q?f8bVU1WuR3zZyIISi0bhJa274?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 95966f2d-4683-4806-f1b7-08db2051973c
X-MS-Exchange-CrossTenant-AuthSource: IA1PR11MB6097.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Mar 2023 03:51:40.6725
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: G0b6OS+pT4kokYUXAymmaLr5R28AanN3zULlWsG/cQGakEf60IIE98N32S0DFp25eeyQIsuteV4JhHFXjAWvcg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR11MB8373
X-OriginatorOrg: intel.com
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 3/8/23 18:56, Lu Baolu wrote:
> The iommu subsystem requires IOMMU_DEV_FEAT_IOPF must be enabled before
> and disabled after IOMMU_DEV_FEAT_SVA, if device's I/O page faults rely
> on the IOMMU. Add explicit IOMMU_DEV_FEAT_IOPF enabling/disabling in this
> driver.
> 
> At present, missing IOPF enabling/disabling doesn't cause any real issue,
> because the IOMMU driver places the IOPF enabling/disabling in the path
> of SVA feature handling. But this may change.
> 
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>

Thanks.

-Fenghua