Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <d7f707a9-945a-bee5-2de7-dd1ff09a79e2@oracle.com>
Date:   Mon, 17 Jul 2023 10:24:35 +0100
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [PATCH v4] iommu: Optimise PCI SAC address trick
To:     Joerg Roedel <joro@8bytes.org>, Robin Murphy <robin.murphy@arm.com>
Cc:     will@kernel.org, iommu@lists.linux.dev,
        linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Jakub Kicinski <kuba@kernel.org>
References: <b8502b115b915d2a3fabde367e099e39106686c8.1681392791.git.robin.murphy@arm.com>
 <ZLFXD0WNDTCU5fHp@8bytes.org>
Content-Language: en-US
From:   John Garry <john.g.garry@oracle.com>
Organization: Oracle Corporation
In-Reply-To: <ZLFXD0WNDTCU5fHp@8bytes.org>
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?THpmRURTMlhCOFU1bm1peWRoQ2U4WXJiM0hXWW9POGxXbDlRcFVZaTdFeDhj?=
 =?utf-8?B?SEdCWkdDdXpRd2J4QUlzZFpPc0tBVlNyRHFWWTlIKzZUQXFhNERzaHNxdHp2?=
 =?utf-8?B?Y2MwVFF5U210NU9tcmIzUXFLZDVXdE9UUUx4R3lXK05GZlRnaW9Ob3RXdmlQ?=
 =?utf-8?B?eDFUcUdFMG53NUp4SU5KWHFWNFArVVpPZFFabTlGWXNzZWNCV25KSUtwZGJu?=
 =?utf-8?B?MUlTZndoTWVwR09xamF0ZDBZV1UzNGhtQ25XcndmQTZkOElnUW1FZ1pZWFhu?=
 =?utf-8?B?WTVkTkUyb1M3UmlVL2FOQ3VralNpV25TY0FXYmdkK0VDNHptK0RESW9hWG1X?=
 =?utf-8?B?NllleUJyYk5tZnlqa2JCZk05SFhBK3NydkFyT25sdGdFTXlZSnd3N2laYWhB?=
 =?utf-8?B?MWVIYVpiZDZXV0lXQU12eXBjNWRheEF4YWx2NFhPWXZ2RVh1clJ2UnhwZHpT?=
 =?utf-8?B?UThZam4wQ1BPcE9sVWtuZ1JUZ085V3ZLMkRGaE11L3RUVFJUMnRMNzh1d0VV?=
 =?utf-8?B?WGplendac3BXWk1NWHFHeThTbFhoVGppZWlST3N6c2lSTUhvdElVMnQxYTEv?=
 =?utf-8?B?TzRkcDBwRE9va2VuVnliUVJYZktlL2ZuQmZMM3k1MVFjWndYUk9HYkRjLzNp?=
 =?utf-8?B?aWlnUVBtWHcwb3orUFhKK0JLWlI2TkFmZ2dVRHFHZmRrd3Zuc0Q4TDRManBR?=
 =?utf-8?B?YkMyNEFUOUtuQi9RSFBobjdLY29yOE9UMmk0RGhNaWpuRUVEZDdHVUM1QTFL?=
 =?utf-8?B?OG9odERDVFNQdVJmQ01kZGM4dTZPUWcrem1ZSGdna0JScjViRWpFajlZV3pQ?=
 =?utf-8?B?enJFd3pBaVpWVlFwTHA0RmJqeVBtbTNlR29uakllNEZUb1BMMjBHcE1MdDVn?=
 =?utf-8?B?MmN3cENVaXI3WmhUcnhDZERTU2laOEhRaVMrUVYzNStscEZWQ0hXN2plQmRU?=
 =?utf-8?B?UlUxMi81RHRCWWFXZGpVSXM2TEdITkk2T3owQkJmWGRiUVoxZVd4OEpCTkp3?=
 =?utf-8?B?T0I5V2c3SjRkajdIL21pZ0tEY0hDMVdIYlB6b20rREVTZXhzUDdwSUoxUXdp?=
 =?utf-8?B?OG1CWjJOV2F2N2ZXcG5ncGlkUkhUU1pwdGFjckNSSUJOdTZYTDhjUFdYT29H?=
 =?utf-8?B?bTIxSEd6Q3Q3SmdXaWJ5Z3IwQ2x4OURMRnlzd2pLVDlUR3lJVDJvU1RzalYz?=
 =?utf-8?B?RzJyTEs1UC92VmpEd1pJMVdxTkJNWTlWQjJKRGhUMGxNMFExby9XdDlHN0ZN?=
 =?utf-8?B?YmFXMGM2dUI5SmdJVElOZWN4Vjd1Y3V6eHB3VklKL3hzNXhjNkxaNEg3SW1v?=
 =?utf-8?B?S3FCK0kvK3dBb0RFTm12RzVyUGhLUk5aeWZzTjdXNXAwMFMyUll4TFN2dHVR?=
 =?utf-8?B?YjRkN0QxUTlaWEFYa09NdXJ4cUM0RG4zTFBJbzBBSHY4bGhyc1NiWnlNZUFo?=
 =?utf-8?B?UUx6Uk5NNFMwMkNCTWxYREtpYzdlbTloQ1VMMHFIblM5R3VJMTJaSEJFb0tj?=
 =?utf-8?B?RFVzR0RiL1h1STF6T3V3ZTNZT2ZZcGdiSjZGMUNaeXpBazdwaUd3R214d2k0?=
 =?utf-8?B?YWZORUwvYlFqclZkSW5PWkZ4V3ZkUldoR1NKMjhKS0JjQk15ZXFKZmZveTJi?=
 =?utf-8?B?czZPVUs4ZzNIWEhYQkhUN0xTSmV3Q25UQy9RT3k5a1MzazBNbm9KOXNKZS92?=
 =?utf-8?B?WkJxOWJaVWpnNUdocXdYWml2M1NUdzdZNmlQQWt3Y0cxOE9nUTdmSS9QNTVy?=
 =?utf-8?B?aWFOSkNjdFhSVVpsZEtpVlE4UCt5N1I4OHdqdE9hSU5VWXdYOUg5MEdKWTZJ?=
 =?utf-8?B?ZndtYlpDejFkU3BTa29odGRtLytER2d5RXpCQ3dHRVo3OUh5N3Y1d1pIM0lo?=
 =?utf-8?B?bUg1azFVN3hxZC8zYWM4NGNSdnA4N28xeGlLaEpIVGR2aFlPY3d4aUpLUHJY?=
 =?utf-8?B?NEZ2ODlONnoxNC8wVEo5eFJ5NTZuRFRqREQyNjNFYW9najdFNy9nK0d1YXZP?=
 =?utf-8?B?T2lYZnpDK3dCU0h3aDF1WTVnRVFpdGtXdTVscjdDZWFIeW91QXBpelA3aHJH?=
 =?utf-8?B?cjVYVTB0WU13N3VDMEdGSXdqTzlvUEhVQnIwZ3dySXFTR0NUOWVkWFVmWFpS?=
 =?utf-8?Q?M7XFrs7I+gxvE9Yv37pdy352D?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?utf-8?B?WU9EUGo4YURwYzFMTU02Ym9vQXZxRk4xT3RLNVhxcHhCTlJHM3p0Y3ozaTEz?=
 =?utf-8?B?OHZFQkdWYVR2TFhGd3N2Ulp3Z0N4Sk5tQmgvY0l1cHY2Y3BjTUIzdUxaSUd6?=
 =?utf-8?B?M05NbHVGSHZ0UVlIUUdkcFJIYm9PeENHUXZPd2poeDJsYS9PVDdXazJaeFlh?=
 =?utf-8?B?MDZ1TVBBL2xrR1lQSEpQN1FkN2FKcDlydW5mekdDdndMU28xTmZMY25UdGlI?=
 =?utf-8?B?Z095dXBQTCsvWmNYZG1CdXZUM1lDMjA4RnhveUJCalBUcTUwUEV1aEx0Slk3?=
 =?utf-8?B?RXg4UjFzQTEzYXY0Vy9mR0tnWVpVOGNEbmtkck1BbFZSWFc3ditVRmhmUHlj?=
 =?utf-8?B?VXlxWHBVSmt3cU5SN0JiaCtWQW1TOWpWQ29VMmdBa2s4U2crNjBIYnlqc1Ir?=
 =?utf-8?B?SWVKblc0TEQ0b3MxSVp5Nnp0eGs3TU9Od3hjNEF3cXdUcmNwRkptWnNaVTRn?=
 =?utf-8?B?TERoNC9YV2NJSHhycFpzR29Gc1k3T0RCMCtxSzZ5QlZEZGkxODhjd01RTWRN?=
 =?utf-8?B?azR2Ty93S2Vld05LSUtwSS9YelgxNFU4T3lUOGMwNERBUllQYkFaVVVzOTh2?=
 =?utf-8?B?czN1RDRyVnFENTlNNzkweFNJT0lrSW9nNkgybzE2S2pZVUd2UEN4M3BPeHZN?=
 =?utf-8?B?SkRONmlucjQ2VDBDOHZVc0hEZ29GZnlyVnQ1TVg0RjB1dFZ5M1VyOHc5dXRx?=
 =?utf-8?B?MEI4aEFHV0hKNmJjRjhiTCtaTmJnS2I3Vnk0c1J1WXdxTVU5andzaUFIWWlo?=
 =?utf-8?B?YlFubCtRSXhSdW4vSldqUjZISGZGWXZ6a2JzOWhEY0hrL2FyMTA5OVZFYVdX?=
 =?utf-8?B?NnZ3Q1pCZjNYU1lFZUtvM0dRbHV4MWIyaVpTeXlDK09kUkExQnBOM0xwWFUr?=
 =?utf-8?B?c3Rha0gxSG9kVStsZnh0WXNod3QrRnNPRlVmY05mbFFqcXdRU1JIOEVIazkz?=
 =?utf-8?B?RzN4MWpDMWxuSXdJOWROMzBSclZjU0hEL00yb1pIWXVSWkprbExmWXV2SjFD?=
 =?utf-8?B?TW1qRjk1bk1WTW1aUWtGekdjREFlQk12aW9SOFZnRXBBZUh0ZEQvSUk3MmVn?=
 =?utf-8?B?Q09xVUNQY3A1dFAydUdObEl0VmJXVnE0a2xkQzU4UWZGSy9HVTkwQ0lnSU1R?=
 =?utf-8?B?cTZvQjJQMzlpZXZTU3FEdU1ZRnVzQXNPZ1JQTFRZY2xOMlZyWXpLaG5PaWRx?=
 =?utf-8?B?WEl1TkY3c3ZoOFhYNi9xeXd3bmZJL1BYM3FMOERTQVJPVTBZYW1VMnM3ZmV4?=
 =?utf-8?Q?B00loAE4Y0a4gJc?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 21c2aa36-c04f-4d28-7036-08db86a7a6d2
X-MS-Exchange-CrossTenant-AuthSource: DM6PR10MB4313.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Jul 2023 09:24:42.1638
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: v+jb7CZwfRwzXMcpq3RiEuVYMJxD6GTvJPD7wNppF7/wCYcaFhLU4pdar/HUpR/ZX0Bi3+UQ0xh8EdKEise3HA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN0PR10MB5141
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26
 definitions=2023-07-17_07,2023-07-13_01,2023-05-22_02
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 mlxscore=0 phishscore=0
 adultscore=0 spamscore=0 bulkscore=0 malwarescore=0 mlxlogscore=980
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2306200000
 definitions=main-2307170085
X-Proofpoint-ORIG-GUID: cCEd_FwXIgrLtimxLGWG5Bs1HjpcLfyd
X-Proofpoint-GUID: cCEd_FwXIgrLtimxLGWG5Bs1HjpcLfyd
X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 14/07/2023 15:09, Joerg Roedel wrote:
> On Thu, Apr 13, 2023 at 02:40:25PM +0100, Robin Murphy wrote:
>> To that end, implement a flag to refine the SAC business into a
>> per-device policy that can automatically get itself out of the way if
>> and when it stops being useful.
> It is summer time and it may be the heat, but I am in a brave mood and
> decided to give this a shoot. I applied it to the core branch and will
> push it to linux-next for testing.

Cool.

@Robin, I think that you sent an incremental change to this original 
patch in this same thread. The issue which it solved was that we saw 
dev_notice() logs many times. I glanced at linux-next and Joerg does not 
seem to have included that.

Thanks,
John