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: <21a1a47d-4713-3c69-b645-c6c74de6cba2@intel.com>
Date:   Wed, 9 Aug 2023 14:11:04 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.14.0
Subject: Re: [PATCH v5 13/19] KVM:VMX: Set up interception for CET MSRs
Content-Language: en-US
To:     Chao Gao <chao.gao@intel.com>
CC:     <seanjc@google.com>, <pbonzini@redhat.com>, <peterz@infradead.org>,
        <john.allen@amd.com>, <kvm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <rick.p.edgecombe@intel.com>,
        <binbin.wu@linux.intel.com>
References: <20230803042732.88515-1-weijiang.yang@intel.com>
 <20230803042732.88515-14-weijiang.yang@intel.com>
 <ZMyz2S8A4HqhPIfy@chao-email>
 <f894d23a-5c6a-d189-57ee-8f2bae0baf6b@intel.com>
 <ZNBF4t+x5Gf14PV7@chao-email>
From:   "Yang, Weijiang" <weijiang.yang@intel.com>
In-Reply-To: <ZNBF4t+x5Gf14PV7@chao-email>
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?cFo0VDd3SU9WWW8yejNYZ1A1R01zNElMRWRDTmIzU1h1b3B6NEVTWWNyaHI2?=
 =?utf-8?B?dS8wc0xTK1RoQndGekxrY3BrQ0NIa3krenFlTEVZLzNRWmxaRll3Nk51R1dE?=
 =?utf-8?B?Sk1NT0dQVGt2K1R2cUIxNW1GYlZIODBtVHNJSXplWlZpWTZjZE9BYnFycTVX?=
 =?utf-8?B?aHhObkNVbHFqYnlUMVlpbGZIazVlVmo2UVNSRUVmL2xjVkJPcGduQVZqL2tl?=
 =?utf-8?B?MitPNHo4OVZtVUhLVVQ3TkhqWFhTWUx1Y09WajdjaFVhOWV5dDhJQU5xa015?=
 =?utf-8?B?SlR6eGVpdWFUS2tVREM1aWNkY0NwTzE3RGZVZTRUS2JreXhUdGgrcHhPV05I?=
 =?utf-8?B?VHdKZitCY1NHUFJVK3VLQmlqZk4veGdkWmQ5YjB4ckF2RFZmcjdLODdTczl0?=
 =?utf-8?B?TFdJaXFZSzQ2TkpUaXNlNGlxQnhpWnFJUEEvU3BCeHlpZURCaVdSbUk2aGdI?=
 =?utf-8?B?TDJaSnVmNm9FRUxRblYwdjlKNGU2L2lDd2pvUnhWN3lCdVlXR1lvQndjcTQz?=
 =?utf-8?B?RFgrTGhNTENNZmZWaUF1RjNtblRncmJuL2dWWUdtU2p3aVZrRDhTSnlMTjM2?=
 =?utf-8?B?UUN3TUlDNEp4cFdBVkVOUU91aDJycEFoVUhLVytLcG1pTzJHZnBMWlNxWC9Y?=
 =?utf-8?B?ZEY5ZGlEbHNuUmlFMkcwU1lYZ3FTRUFjb2hVbTZKcDFLcW83SnRGSHpabkVL?=
 =?utf-8?B?eXVGeWxOL2M1dzlHNDFwbng5L0hBTGorcE92cDZiK2hldkR4NzdOMzBCa1NW?=
 =?utf-8?B?dE5PbGJ3RjE3RVIzSWt6NThoWFlsNFEwc0xLU1U3L1NVT1JDMHI4QmZwbGhr?=
 =?utf-8?B?RVdVcjIxdzlDT01UdkpETjJGY1h6STBJbHhIQ3dRck5DM0VMUWlGb0RPTFdh?=
 =?utf-8?B?SzI4dUtpc25sMGgxT0RHUDRGd3NJZG9MMG9GQUtxUXRDMU11QVdTYkl4MERa?=
 =?utf-8?B?QXhBRzdtd1dnc0ZLeGFLMmVQaE85K0dURmJNUVBPeHBpZ0hDQis5emRJZVBF?=
 =?utf-8?B?SXhxN0R6MlRZcjJpNGVzNUtVSkZJQ1kzck9TOXpYaFBPS01jZGV4anhsV0hJ?=
 =?utf-8?B?NmJXSTJ3Mm95UmtlbWNxckFHOFNBMTZpRU9KNmZwMHpLS05nUmFiMUxpT1ZY?=
 =?utf-8?B?NmR0Z3B4T2hXSGtCRGd0UndFclcwdFB3dCtrdG5zeW5OUjNJcXVKN3JrZVVP?=
 =?utf-8?B?ZjAwS0hxdTFTbXRCMFI5R2ZQYmNrdU56T2dVVlowdE9FSGNWYmZudjRiVXVY?=
 =?utf-8?B?eENVd0xVRGF2ODM4RnRxRW9pODBQTjJiTWJDMzNBdnJlc3VNcnkzMzVXQjFL?=
 =?utf-8?B?S2c4ZjIyQmVjS3hjL2x1Y3J4SHYweGNaSERYejFXQUpUREdEQUFQNkV6bjNm?=
 =?utf-8?B?aGJMTmJqMUZCemFCREtBWG5XUDZqT0hLaXphdTBraUtBYmtZamErNVBoenBN?=
 =?utf-8?B?L1pOdzl0MHVzOVVQc0ZXNDJ4RVNTZTJwYjd2Z3VrTnMxVGM3d2RpT2hzR2RT?=
 =?utf-8?B?NEhGVXlFZnlkdlRNRm9HYVVEbjYydEVFcFNJRmR3bm41WmkvQVUxbUVSRjdW?=
 =?utf-8?B?d3BQais0VEpxaFR2RnljRDlrQ0pNUEVyUWd3N1VJYmQ1VUo5cEpITC90dG1S?=
 =?utf-8?B?RVQyMW13WGs0TnRMb3JrY3RGdHFCdUJFSUh6c3Rsc0oyRGtOK0FWaWFndW5k?=
 =?utf-8?B?djRFRE8wN21SdTBRZ0pvTzkvSW9TRzJuUTJlNlM1UWVVektKbURXVUJQaHVv?=
 =?utf-8?B?eDBkKzY1K3lRVVlFdUdsSDQ4L3lybFJpRTk2aG8rVGs1L0sydlhMV3ZlZk9x?=
 =?utf-8?B?bG1icFBZUXczSkdZcDVJSWRyRUNHZ3JQUUxKTkFpN3h0QjcrL1MrcXl2eVZ2?=
 =?utf-8?B?R1Z0OEtFeGY5eldCZFkrYTdFRWVLSHpFaC9aUXBlckRZb0ZINGZyVnVJWmZO?=
 =?utf-8?B?SnMvWm1oYkR1a1p1dmV5TVhHbFpFV2VoWUVvMlA0MURwZkh0enY3SFRKS2hV?=
 =?utf-8?B?NG1aYVJ3dE1ybEtYbHJSS0tFQzAzYlp5alA3WFlGeERRMnJPMjR4bU9DVWFU?=
 =?utf-8?B?cG1SL0R0SjlNaXcyeGZDWGdteGtVV2tIQjN2OTZ0UFhUZDVLV2w1RkJHeUxa?=
 =?utf-8?B?NmlCSTNLUVM4OVJBRlhUcmRYbkhPWDVKekhBT1ppSTRVNHJKSVNxMHBGRHFl?=
 =?utf-8?B?eGc9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 4f1de976-3f6c-4f03-53d7-08db989f6fe8
X-MS-Exchange-CrossTenant-AuthSource: SA2PR11MB4972.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Aug 2023 06:11:14.9126
 (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: Irzs4zxlGrjIcHBo71XsfN2ztFDvBQG7VGQvpuTrh+If1rOZJOAjYn6mWcpS34GwL1xpGNackgubg4Z7qU9mcQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR11MB6957
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,
        SPF_HELO_NONE,SPF_NONE,URIBL_BLOCKED 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 8/7/2023 9:16 AM, Chao Gao wrote:
>>>> +	if (kvm_cpu_cap_has(X86_FEATURE_IBT)) {
>>>> +		incpt = !guest_can_use(vcpu, X86_FEATURE_IBT);
>>> can you use guest_can_use() or guest_cpuid_has() consistently?
>> Hmm, the inspiration actually came from Sean:
>> Re: [RFC PATCH v2 3/6] KVM: x86: SVM: Pass through shadow stack MSRs - Sean Christopherson (kernel.org) <https://lore.kernel.org/all/ZMk14YiPw9l7ZTXP@google.com/>
>> it would make the code more reasonable on non-CET platforms.
> then, can you switch to use guest_cpuid_has() for IBT here as you do a few
> lines above for the SHSTK? that's why I said "consistently".
Oh, I should use guest_cpuid_has() instead of guest_can_use() here, thanks!