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: <579aec6b-78d1-57af-8e17-59cbe59f168a@amd.com>
Date:   Wed, 16 Feb 2022 07:41:59 -0600
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.6.0
Subject: Re: [PATCH v4] x86/cpu: clear SME feature flag when not in use
Content-Language: en-US
To:     Borislav Petkov <bp@alien8.de>
Cc:     "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Thomas Lendacky <Thomas.Lendacky@amd.com>, hughsient@gmail.com,
        Martin Fernandez <martin.fernandez@eclypsium.com>,
        linux-kernel@vger.kernel.org, Brijesh Singh <brijesh.singh@amd.com>
References: <20220216034446.2430634-1-mario.limonciello@amd.com>
 <YgzTCtlMq9+4IsZ4@zn.tnic>
From:   "Limonciello, Mario" <mario.limonciello@amd.com>
In-Reply-To: <YgzTCtlMq9+4IsZ4@zn.tnic>
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?UHNCWEpjS2Q5cDExYTZYWm9aMmQ5b0RpSnVscFoxQnp3VHdmTU5KN0xjTWo1?=
 =?utf-8?B?RnhvSHZ3S0d3QkRnaFJWVW5BbkdORkc3MXBxSiszSDJnQTdDSW1HWkJReDVa?=
 =?utf-8?B?ZEs1UzN3S2VZcU1adlRkYWNQTEVPWVkrNnBCWU5yMUxTR2hpUlFFUHZaQUNz?=
 =?utf-8?B?T0t3TnlmblRnbVhFQjE2TG0rYm0ydEo3T0dWREd6dEVpQkpqckwyd0RtWE9y?=
 =?utf-8?B?WHVzaVd0eVN5U0JudFBoNDdpanRvdDUrS1kzWWJWeEduVmJRaUluSkJsWEFv?=
 =?utf-8?B?LytUNmZ6aUVCTVdERGdQV2lvcStPVlJFbm0vWUdmTFlpU0QyRVZTREJLdEh0?=
 =?utf-8?B?SlVBZlovbnlablQycTF4NUs3ZkJmTzc1aklWTEIxQmpHS0FMUWRvQm5MNWFh?=
 =?utf-8?B?TGwyOVQzMDBXQlgxNXBVcWl6Q3ppRW1mMnNsK0FZT2pXWEFpRzRuWFRoN1lY?=
 =?utf-8?B?ZFFVakdkSmk0QVVQRVd6ZHFFN0pYYzNzN2ljVHJUMU5nM2EwaUlTM3RBYkxn?=
 =?utf-8?B?YnlhK2x2QXFZVUFudlJ6NkZKYWFsVXN6SXpHeFZ3NlR6RzZ3Z05wdFFOWE5i?=
 =?utf-8?B?dHVqSGM2eHgzT2dMOU5EdmUrNFFQR2svV3VBa0lKTFlHaHE3WHBlZlh1bXJX?=
 =?utf-8?B?SmFrTFR5ZWtvLytmVGtwRkZ3NFZnTWhZTktaMEFtR01vc2RxdnA2aThvSFNF?=
 =?utf-8?B?VDA3WGZtMzVIWWlsOWQ0dWJ3NklIUldMMVNWRlo0VjJaRXpBd295WkxtSGQx?=
 =?utf-8?B?eUZXZzFGbXJ5ZTlwbnpHNGpuc0JBWVZtR2RPdVlNaXJFQ3VBcWxZWUVldTFR?=
 =?utf-8?B?MkloTno3M2dWVkVsTU9ka0E1bHYvbGFydnp5dS9iSmVUQ05QRUdBYkVYUSs1?=
 =?utf-8?B?OEhxYU9aTGlLaWJSeWFybU4vUUh3cndpNklkNUk0Nm02aXdmSWRXTkZFS0cy?=
 =?utf-8?B?Zy9PR2JQVkZrMktFeVNjSTdyaGRBZEhOQnNmRlhITEI5M2M3Nk5yVkJSbTQv?=
 =?utf-8?B?czlFQzEwNFAxdEVuWXViMCtHMnllbGRWYUVjRGU2cHR3VWJWSzh2OUlKWXVp?=
 =?utf-8?B?Wmd5N09pa1FMc1FCRkRvQVUyTktTcHNuWHdId3BpMmlhQzFBeTVnY0h1ODNJ?=
 =?utf-8?B?dTFnR3dkSkwzeWJCUldRL254bEozdE02aDFMU2NpN3FaNUFKTzNPVDdTNUZF?=
 =?utf-8?B?dW5qanlDMkJHUTBFbGVXTk14MHJRQUxuM0FzU0c2K3lUY2xsN0NPVERGZWJN?=
 =?utf-8?B?M25DR3ExOFd5bStKTUhEellJL2szWS9zOE1DSDZETnpjRnhhRzFJMU15QXVq?=
 =?utf-8?B?UTNjdGVGNTFSMk9sZmk2NlM0YWxqeFFKUUgrZWZnbVdvL0VmTU1HdzVrYW0y?=
 =?utf-8?B?REhVbFVpUDZmWXMvdWpPak4zVmpVQTd1aDFaYThVK1ZQS1JLUy9FT3dodVFj?=
 =?utf-8?B?SDlyR3NsZVRCc2p5NHFjWnRSaTFJUVFkZVVHcXh0S3h0NlRpS3dYbzdKZHVm?=
 =?utf-8?B?a0JtSmZkUURUcDJBNytHSjUvUlVsVU5qaXkwR1ZWN0VZVWUyNCsrYnFRc1lv?=
 =?utf-8?B?TStna1ZpTzEwN1dEOEt2MXkvRm0rdlFHSmFKRUZVZVZlVkpVUDZsVkw0SUpp?=
 =?utf-8?B?VzVtTjU0NkIxMVgwTG1TN2o3Z21FaDRGTlovOGQyMXQ4UDdYVEJSREZjUTZN?=
 =?utf-8?B?SnA4M0pyeVRJVmVFeXJ0NTVIM2Y2L28zUUdEZk9Kd2s4b3JyYk5UcmtkWVpp?=
 =?utf-8?B?MjYzTHV2a21jbm1kcWdGQzZmdGZ5TTU0cUpmbmtmMWwrTU1GekFZQ0NFMkdm?=
 =?utf-8?B?VDNoejl1anRmNHRjMHdaVWhYWEZzYUthT0JaR291VjlWUnE0QnZzZlhNeFY1?=
 =?utf-8?B?Mkg2Rk13WUlrOFM4czFBT3VjRHpRVEMwbStVSnc4MWVnS3piNS85eFVkU2sy?=
 =?utf-8?B?RTllRURkcWtRYnNLbTd6QXcxNlhIVFVWcVhUSXBjUDVySkpKV3NBUlIyUG53?=
 =?utf-8?B?dFNpdlZ1RGFoWWJIbU1tQ2VTRmZCaEhvOFRhVFVUd0ZYOEtVU1k3bS95cUpm?=
 =?utf-8?B?dXB0RTJmcFJpYXd6THlsa3NIS0luc1R2S09wK3Bod0JFYmgyL0l6b3pmc0w5?=
 =?utf-8?B?SmtYWTJpT1JSY2VxY28xR3VMNlpvUy9BU0NqUTBTellmUzBZMmExam9ZQklI?=
 =?utf-8?Q?9yvWvHe//UX1Xa/+LFkyTWc=3D?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 36ad91ea-8c51-4bea-9920-08d9f1521cf9
X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5157.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Feb 2022 13:42:02.7242
 (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: 6W51ekiI0ase7Qrbtuuk7sTFULH7al+XCUd0lYQt+0GdC9U/CMw+SfwUBg0GPE9XTWbqpK1JNiqtUX/EOixerg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5042
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,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 2/16/2022 04:33, Borislav Petkov wrote:
> On Tue, Feb 15, 2022 at 09:44:46PM -0600, Mario Limonciello wrote:
>> @@ -607,6 +609,9 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
>>   		if (IS_ENABLED(CONFIG_X86_32))
>>   			goto clear_all;
>>   
>> +		if (!sme_me_mask)
>> +			setup_clear_cpu_cap(X86_FEATURE_SME);
> 
> Why not "goto clear_all;" ?
> 

"clear_all" clears SEV and SEV_ES as well which as pointed out in v2 is 
incorrect.