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Date: Wed, 10 Dec 2025 11:10:57 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich Cc: Andrew Cooper , xen-devel@lists.xenproject.org Subject: Re: [PATCH] x86/pod: fix decrease_reservation() clearing of M2P entries Message-ID: References: <20251210093513.59534-1-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: PA7P264CA0007.FRAP264.PROD.OUTLOOK.COM (2603:10a6:102:2d3::11) To BY1PR03MB7875.namprd03.prod.outlook.com (2603:10b6:a03:5b1::10) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BY1PR03MB7875:EE_|IA3PR03MB7546:EE_ X-MS-Office365-Filtering-Correlation-Id: 232e6dd1-8e4a-4ab4-b61e-08de37d46fb3 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7053199007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?TWhxNHA1Z0paSG9acnZieU42cGFKZ1B3MG1mdWpOeTA4aDZkaVhuc29vMDVV?= =?utf-8?B?cDRIbnR1WHhQNDhjRm42b3JGU1R6ZnFzZmxWdE16YjVodGpUT3JnM2FEelV3?= =?utf-8?B?MTdOdk1wYnNQV2xaRWtWZzlRZlpaaTd2MndNYzZCL0ZzYlM3Sm5haWFxaEoz?= =?utf-8?B?alFQL2ZhbStyMTMzUHhmQkJtaE9LdXBOemVnOWh5dEZTWTZxejJLcHcyQ3Uy?= =?utf-8?B?SzJ3M20xVW9JQURNZzhZVlIwaU1sM1FWRW1aYXVXTWgwaGVDa1E3bHA4MldD?= =?utf-8?B?NmViM2RzRXB4MXErQnlNU2NQamRRUkNYdUJXOGtOT0dMeUhFOHAxOUREa3pE?= =?utf-8?B?WlZkL2VJQ1ZNTnZUNnZydVhnaVNZQkhwMlN5T2VrZFdtZEk5Y2ZCekRNa3JV?= =?utf-8?B?MG9NTVVxNzV6NzF1R2hyZEJpRXBwLzFGQ0V3ZXZVWERoOUhzY3R6NHZ5c0Zt?= =?utf-8?B?dlFoYVVUNUdIdjBWY0VpcEhpaUpXaUI0bEpvdzI0dWVSRzF6UW11WWJnQkts?= =?utf-8?B?VldTQU5JdnJSdldzZXZuSVpGUUlFbXN0aDh2SW9jVjZRNGZhNW5hYzJKVWZj?= =?utf-8?B?bzY2Y1JXYWZqM0JwM1E5Qk5hWDNBY1pyZTJJZWhMU0s1SCtZbnR4ajJvNW05?= =?utf-8?B?b1hYKzREUzJOODJSNnUrYWtWNEVtejlBU0NyNWRNb2s5a0hIWldaWWNQZkpr?= =?utf-8?B?WnNsZ1ZRZlZyZkxHZS95SWl6VTNQZmhFM1g5MVVuZDJVcDNFZHRSSFlvc3lz?= =?utf-8?B?TUMyZXVaRHRxRlVXdzlMVGFHc0pvTWhvNExxaDYyTkV4T3dJMFAzN0xtSDBT?= =?utf-8?B?d1NBRklNRjFHbjZUYTYxejVISDNubHdpcGhQS1p4cWRlaUNzUU9QVm9YRW03?= =?utf-8?B?T0o1ZFJkT3ZZSWJNT2pUSytpTVJMWU1zdFNwbTNKK0psRjNnU3hTN3B0S3FV?= =?utf-8?B?aFJvZ2JNc25BL1V3dnNhQnNZelhYQnN1TmxnMHlqYjhuTGZRNHlKMGwvMzB5?= =?utf-8?B?V0tpRGVsTERjdnd1aVU1d3V4M0x1RjNBTko1SzBQQ2ZDcXJObjBCUWRlWHBI?= =?utf-8?B?SE5ncjBjNHdIaHRWUGlQTEZMSW1FcktRWkx2K09iK2NTdGdPcTVzZ0doMXlH?= =?utf-8?B?UVhYR3RZVkYyUzZqcVlJd3RPNDFDTW5NcWxkUU9PNERrdlNEcmlxM1BsbVBT?= =?utf-8?B?UUcxM0Mvb05qZ2tOVTBpV3pmM2EzOE1HSXArV3FVUjRlTWJwK2xndmV6K3k2?= =?utf-8?B?WDFBaGRPdURpREprSFBzS3JRRmIwdHRyME0rUjFPLzlTVk9OMzd2M0xxcmFZ?= =?utf-8?B?aGdqcHNMUmRCQ05VeXpWbWhoTzJUMnp0RGo0TWNtMzFld2R4RHljOXRZYzNR?= =?utf-8?B?bENUbG9oMzYwRFI4RXVlUkkyUWxUOXdzdDQwZ3VROXRLQlNrUTdtdVVsdC8w?= =?utf-8?B?OWRUVjh4TEI1RHArZmwwcWFXTGluWU15ZmVxc1c3bE9mVDlZTDlneUhxNjNQ?= =?utf-8?B?RHV1aU5UY0dpbTZSL0kyM0NENHRnVDk0U3BldnI1MFh3Mk1VeDd6VXpFeEFB?= =?utf-8?B?YWdTNXdFbUwwc2tFRVRCa2d1MzdWWXdTNXczUS8zSGNoL2Q1YmhaN2REYkMx?= =?utf-8?B?Y1gySHhIaFRjWGF1ZWNnZm5DWDl5RVU3TjY5YjBYVmNMZWRaWTFJK3owK2d2?= =?utf-8?B?VlV6amlRQ3gwU21zN3pWOHRXcm9ScGtkNHNjVVJ2ZnJ2cEk3U3VjVzF2a2Q5?= =?utf-8?B?TmtJdXVSNExoLzExVjlWNVk3MFlHOXViQk1kcDE4UlFhb1h0ZXFEUG1EK2Ex?= =?utf-8?B?WUpyMFdZRGZPTTFZVTZPQWVzQndrYWozaktVM0RJWU9NZ21FRXFaRUxJcElI?= =?utf-8?B?UWFaM0xtWDFpRTNKSm9Ia3lwcktkeVhabnJYTVR1aFE2SXBVaFptMFJZdDRs?= =?utf-8?Q?0Iw8IbzboOJzAkhyvdYIs5oSTj9Yk5bs?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BY1PR03MB7875.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7053199007);DIR:OUT;SFP:1101; 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This seems to be > > an oversight from the change that introduced support to process high order > > pages in one go. > > Ouch. > > > Fixes: 3c352011c0d3 ("x86/PoD: shorten certain operations on higher order ranges") > > Signed-off-by: Roger Pau Monné > > Reviewed-by: Jan Beulich > > I'd like to note that things were broken in the same way before that commit, > too, simply because the order wasn't taken into account all. (This is not a > request to change the Fixes: tag, though. It's just an observation.) Are you sure? Previous to that commit the order is not taken into account, and each 4K page is processed independently: the `i` index is strictly increased with +1 for each loop. Thanks, Roger.