From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 329F0740032 for ; Sat, 20 Jan 2024 16:03:38 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=lQUcPsaOi4CVJRMRsZcWWUiMEAcU8bQk8z3jQhMEheo=; c=relaxed/simple; d=groups.io; h=ARC-Seal:ARC-Message-Signature:ARC-Authentication-Results:Message-ID:Date:User-Agent:Subject:To:Cc:References:From:In-Reply-To:MIME-Version:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Language:Content-Type:Content-Transfer-Encoding; s=20140610; t=1705766616; v=1; b=lgDs8M9wpAqMFXMSdMdrZ4/fVQKo3V0t7WF1hTPNT/iXwUHyRvUhatb/nQD4iOZ2VAHCZXEJ NzSlSRhM2ApUt6KukwbUOb1+roOcf51rdL2xJZtEXKgjWrNdz9qBmjoNeNwUt8uX8WIgIwKEKiA Lmb6Q4i1kNi6iUljAGtys1wg= X-Received: by 127.0.0.2 with SMTP id 9OYGYY7687511xpbmqmvT2aq; Sat, 20 Jan 2024 08:03:36 -0800 X-Received: from NAM02-SN1-obe.outbound.protection.outlook.com (NAM02-SN1-obe.outbound.protection.outlook.com [40.107.96.85]) by mx.groups.io with SMTP id smtpd.web11.25813.1705766615900501708 for ; Sat, 20 Jan 2024 08:03:36 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=cn+Sfd7lfR3kW1i2pdQZhvpiZ0W7T9+0x+sIS1QlPG6GUi9bPEuXu4kqSVcMgk04P1yjnYCklEv+TGUJWqbN/KdcR2tWUqnFvUY6UkMp9k+robfLm+5VNlv26TQdxK5VyAQi0oyRB4ZXZKId2TePDN+bQ6vCGuW0KkR73RovFg1muys8fcELXpkORzFW0ImatcIy4b+tdmQkJqinjsLHppNJo+00IO4p4F0ogQjfyblTjQOKGI0SSXbGcbD2bOiQogKuE+p2ImbfcAMFwen/gFHDzY3g77Z6s9pBOHH2HMZ3D0Es5F3gZOYygiaJ4GGXsdu8GdO31l0AfaNxTugRzA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=T/OXFu2N2qxMPtryP95BBcWwfU545/ShNlfULi+/+nE=; b=Sp93qeYVdmGmUoL+6Px3Flt9j+G6FQx0vFGQZ9GmLph5fYosh1oDVruouxKvzKb+0LIunbLnX8tdHmOhUzTDNku/fDk8OuRjq/ADfxSiWRtmvZXUJIIVLEfAKnSQ+U3h+qnbGeDf38IOWMJItGM7TRTlKelDQAdjFcwbMAVuuhqO51xC2jhCTK3hzm1kz42jgKZQpoFuFxdz/ud9ilUGPvqnULGklO6H+KxuyIBiUEdrts0r177vfWL5phHbVf5vmY9lPc8ehkb1mKa+8QQnSyp6taGignl4F5nkzCaRxIrjoAkXH5z0Nn2JXBejOuMD1q5Y6eVzquhTWAJI+K8FUg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none X-Received: from BL1PR12MB5732.namprd12.prod.outlook.com (2603:10b6:208:387::17) by SJ1PR12MB6121.namprd12.prod.outlook.com (2603:10b6:a03:45c::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7202.23; Sat, 20 Jan 2024 16:03:32 +0000 X-Received: from BL1PR12MB5732.namprd12.prod.outlook.com ([fe80::200:c1d0:b9aa:e16c]) by BL1PR12MB5732.namprd12.prod.outlook.com ([fe80::200:c1d0:b9aa:e16c%4]) with mapi id 15.20.7202.028; Sat, 20 Jan 2024 16:03:31 +0000 Message-ID: <72123232-5a27-7778-591d-69fc7fda0881@amd.com> Date: Sat, 20 Jan 2024 10:03:29 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use AsmCpuidEx() for CPUID_EXTENDED_TOPOLOGY leaf To: devel@edk2.groups.io, ray.ni@intel.com, "Kinney, Michael D" , "Gao, Liming" , "Liu, Zhiguang" , "Dong, Eric" , "Kumar, Rahul R" , Gerd Hoffmann , Ard Biesheuvel Cc: Michael Roth References: <17952A20A9E21541.12603@groups.io> <26becea4-2ad8-4773-ab3d-5ad98ff48759@amd.com> <179BD02AA4207037.22216@groups.io> From: "Lendacky, Thomas via groups.io" In-Reply-To: X-ClientProxiedBy: SA1P222CA0155.NAMP222.PROD.OUTLOOK.COM (2603:10b6:806:3c3::25) To BL1PR12MB5732.namprd12.prod.outlook.com (2603:10b6:208:387::17) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL1PR12MB5732:EE_|SJ1PR12MB6121:EE_ X-MS-Office365-Filtering-Correlation-Id: 95e7facc-6f65-485d-2349-08dc19d15953 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam-Message-Info: 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 X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?L1A5TVFxYUs5WXdOTG1SbUhXT3NZWmkxY2ZHTUNHVjFKc2ZOS2VzRmQzdmhZ?= =?utf-8?B?ZDRBcEIrQThhcDBFZmlnSjR5a2ExcW9tbzBBQ0JZYXNkQktnczE0NGN3Ujlu?= =?utf-8?B?MWNDSmR0Z2FLbzB3NGtpVW9ERFZiZDhWd0RER2xyeUdnVzV3cUc2RU40NE95?= =?utf-8?B?YU5aMmNubnZrNjRuRlp0am8ydnBZNEQ1Z0FCeVRoeG9VTHQ4UytYeWpoUXly?= =?utf-8?B?WllkaWsyazVWcFNybERTVlVnQ1dheU9HM2lKZE5JdCtVMmZQVFcxSm5BUnds?= =?utf-8?B?V0g3SGRPNkpTNWlOeUZrL3BMVVI1SGFvNUFJWTdIWDRRSGNoWWNBYlI5dFE3?= =?utf-8?B?NlMxZTRDRUE0bS8vVzc1cGhIMEtjWW8vK3J5WTJ6bWg0aDA4RlREcytWQnJl?= =?utf-8?B?WjhjS1FpWWEzY3V0YVEwczFKOFRJb3NuM0REMk5oMys2TmRzaWpuVWZDQlFG?= =?utf-8?B?ZlVjRncxM2NnWmJMaTdXc0V4ZjlhYWg3RkFlQ2phbStBcVRwcUdjV3lwdVdp?= =?utf-8?B?Q3lPVEdaODA3a1phZmF2MVRGWXRXVzR2eStET1k3Z3NqUnFnRmIrc1hLYW1z?= =?utf-8?B?MHRDZDVETkhSMGxtZGhnaGxIU0U2cEptQmpZVWZQYzdlWGp2UTJZQmZYNEsw?= =?utf-8?B?Z3ZKZFlSNnZ4bjRFMFcxbkF6SnRIbVFTeU1yd3lOaXZmWE1sVGoxK2JrWWtm?= =?utf-8?B?NmhLOFRvUWNsRkZXSnJjUFdYU3piTzdNKzFueEN3T1FGNGM0QWxubjNXSS9w?= =?utf-8?B?dFFVbGhmdUFjQjhHRHNEUlBSQzRwdGtIUzZVRUNoV01XRmtiMy8vbU9DdHpy?= =?utf-8?B?OGJ5azBzVG9OUEZpN3k1L01wcjlxMEFUaThUekhLK0VnQlNhMjhvWkxzaGVp?= =?utf-8?B?ci9DUjUvYjBsM3NaMlZaY2xhYnNxaFZsdzhLQzJQTzdzY0o2QkxIbHNhc1Rw?= =?utf-8?B?RDJRRlljYnhJQW9Tdm1tUVlBeXVZVEVGWGQ5bk9IVXV2OTdqamtmUTVQcllQ?= =?utf-8?B?L1RMT3Y3RzgzZEhEeHZTWUp1UUtoNnJGZ0x2MExtT0Z5TzduaTEzQTN2NmpK?= =?utf-8?B?TWlWb0dGT09uQjBxaUpscWtrd1p6VWdjbHdPV1pLZlc5UlRvOFlVWm1VQVV6?= =?utf-8?B?SXhPbTNxNGx6K2tIbEF3ZHZzTmo3OFZrd1phUHd0bHE2Y3R6WEMyaHY4KzdC?= =?utf-8?B?Wk8rc08za3pZZFFjUlo5UERwSHFmS1hMNlFtVmFPUWRjOWhyb0diZ0pKRFJo?= =?utf-8?B?UUtiZE9HU01kbFVNdUJ5TlgzcG1iYVlIOVZWS1l5MTdPUFpYVmJIZml0ZVBS?= =?utf-8?B?dXQ3Umt2T0hiWE11TDMzUmNEMkxYWW1YMkoxV2hTVStSajlwSjNMamhPZlYw?= =?utf-8?B?LzI5c295N2JFRkFkY24rY254Z2RhK2RoZVp3c00vSXZOUWpIUUxpcTBOV1dt?= =?utf-8?B?dUs2YThUUDYvM2NJdmkyS0Y3WmoxWjhwVklhcDM4enRMeHl3bnhNR2pTQTB0?= =?utf-8?B?RmVNdkxONmVJN2tZcXI3NzJpQVdYNTVnOVU4WERZYXFIK2pORDNCY3VGMzBo?= =?utf-8?B?ek1uSk1iRitoRUovYTVyZWM1OGFOTjlQQlNYMmp1Wmxiek1yVFdPeXB4QWpy?= =?utf-8?B?dXo4eDEvQ0wxcHhWMUlIQ093ZnA1UXFzZjh4T29icG12cDYwWStlOTArOUxP?= =?utf-8?B?UVV2N1FrNEROZk16SitENDBrTDVGcHhNT0swUndBeUM1K3YxVGdtVXQ2UlZF?= =?utf-8?B?MkY1UWVFZHNrdnNEeDQ0VkdtdDE3WWJPZmw4YWZVOVFNaE1vdkZpQXlyV0JL?= =?utf-8?B?THhuR2loWXdsK0xOdy9ieTlIYUZQMVhkcFE3SGN2Tklnd0tZVXg5c0lSK2Jv?= =?utf-8?B?bU5idmlyWE81NGh6UHpObXVKZnk1ZHZ4ekV1MitjWVZFOFpSY2NQNFk0TWgy?= =?utf-8?B?MXM3a3NTZVloZklCaE1pbkFzRWF0Z1k0Z1FqSEJmUnpkbnlZZWx6OE5JQzVQ?= =?utf-8?B?OUdGOG1VVFN0RkNZWkFDenBXM1pnRFQ2dUxXZnlqN0hxemc2UWdUQlJLQktn?= =?utf-8?B?OGJpT2UzRVpXUkhwaHdaeEFoTTdaZ2tzcHlYZXFNNTBEQy9YQysrWnduNnhj?= =?utf-8?Q?Nh1unpL3duPBrpTn+pP2G8GTb?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 95e7facc-6f65-485d-2349-08dc19d15953 X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5732.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jan 2024 16:03:31.8238 (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: 7p9DN8P4p9pALli5Doinb80n9vtH6HayUlUingLG8iHRks+PByYs7dvuvf+Dr0d3rgmCrnjl1mFdjc2nyqVK3A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR12MB6121 Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,thomas.lendacky@amd.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: X-Gm-Message-State: FuGp8Y15zEJbdBEiBQcyzOSax7686176AA= Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=lgDs8M9w; dmarc=none; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}") On 1/20/24 00:48, Ni, Ray via groups.io wrote: > Mike, Tom, > How about AsmCpuId() adds ASSERT() to reject those CPUID leaves that do n= ot have sub-leaf? Do you mean those CPUID leaves that do have a sub-leaf? The worry I have here is that it becomes a maintenance concern having to=20 update the list of leaves with sub-leaves whenever a new CPUID leaf with=20 sub-leaves is introduced. >=20 > Another concern I have if AsmCpuid() zeros ECX is callers would call AsmC= puid(leaf) instead of AsmCpuidEx (leaf, 0). > This would cause the caller code a mess. I think it's just a mindset that I have from kernel programming. In Linux,= =20 the AsmCpuid() equivalent will explicitly zero the ECX register so that=20 you get the zero sub-leaf if that leaf has sub-leaves. Using AsmCpuid() where ECX is non-zero and possibly random, could make=20 debugging harder. By zeroing ECX, you will get repeatable return values to= =20 help with debugging when things aren't going right. You could then make note that AsmCpuid() always returns the zero sub-leaf= =20 of any CPUID leaf that has sub-leaves. I agree in principal that if the CPUID leaf has sub-leaves you should be=20 using AsmCpuidEx(). But as Mike points out, if you happen to use=20 AsmCpuid() by mistake, then the behavior and returned values are not=20 deterministic if ECX is not zeroed. Thanks, Tom >=20 > Thanks, > Ray > From: Kinney, Michael D > Sent: Saturday, January 20, 2024 9:49 AM > To: Ni, Ray ; Tom Lendacky ; d= evel@edk2.groups.io; Gao, Liming ; Liu, Zhiguang ; Dong, Eric ; Kumar, Rahul R ; Gerd Hoffmann ; Ard Biesheuvel > Cc: Michael Roth ; Kinney, Michael D > Subject: RE: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use AsmCpuidE= x() for CPUID_EXTENDED_TOPOLOGY leaf >=20 > The issue is if AsmCpuid() is called for an Index value that does depend = on ECX. That would be a bug on the caller's part and would not have determ= inistic behavior because ECX on input is not deterministic. That is the co= ndition that would be good to catch. >=20 > Mike >=20 > From: Ni, Ray > > Sent: Friday, January 19, 2024 3:49 PM > To: Kinney, Michael D >; Tom Lendacky >; devel@edk2.groups.io; Gao, Liming <= liming.gao@intel.com>; Liu, Zhiguang >; Dong, Eric >; Kumar, Rahul R >; Gerd Hoffmann >; Ard Biesheuvel > > Cc: Michael Roth >; Kin= ney, Michael D > > Subject: Re: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use AsmCpuidE= x() for CPUID_EXTENDED_TOPOLOGY leaf >=20 > Mike, > For a certain Cupid leaf that does not have sub leaf, Cupid instruction d= oes not consume ecx and it always fills ecx with a determined value, define= d by sdm. > So, I don't see any hurt to deterministic behavior if not zeroing ecx in = AsmCpuid. >=20 > thanks, > ray > ________________________________ > From: Kinney, Michael D > > Sent: Saturday, January 20, 2024 7:16:14 AM > To: Ni, Ray >; Tom Lendacky >; devel@edk2.groups.i= o >; Gao, Liming >; L= iu, Zhiguang >; Dong,= Eric >; Kumar, Rahul R >; Gerd Hoffmann >; Ard Biesheuvel > > Cc: Michael Roth >; Kin= ney, Michael D > > Subject: RE: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use AsmCpuidE= x() for CPUID_EXTENDED_TOPOLOGY leaf >=20 > Hi Ray, >=20 > It is about having deterministic behavior if a call if made for > a CPUID EAX value that does depend on ECX. If ECX is not zeroed, > then it will have a random value that may return different > information. >=20 > The problem statement from Tom is not about zeroing ECX. It is > about avoiding code bugs where AsmCpuid() is called for an Index > value that is documented to depend on ECX. In this case, we would > want an error condition so the developer knows they should use > AsmCpuidEx() instead. >=20 > From looking at the Intel SDM, there is a small set of Index > values that do not look at ECX at all. We could consider > adding an ASSERT() condition in AsmCpuid() if Index is > a value that depends on ECX. Perhaps in DEBUG_CODE() so > it is not always present. >=20 > Mike >=20 >> -----Original Message----- >> From: Ni, Ray > >> Sent: Friday, January 19, 2024 2:01 AM >> To: Kinney, Michael D >; Tom Lendacky >> >; devel@edk2.gr= oups.io; Gao, Liming >> >; Liu, Zhiguang >; Dong, >> Eric >; Kumar, Rahul R <= rahul.r.kumar@intel.com>; >> Gerd Hoffmann >; Ard Biesheu= vel >> > >> Cc: Michael Roth > >> Subject: RE: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use >> AsmCpuidEx() for CPUID_EXTENDED_TOPOLOGY leaf >> >> Mike, >> I agree with your words after "However". >> Zeroing ECX in AsmCpuid() is confusing to future code maintainer: If >> CPUID instruction does >> not consume "ECX", why is it needed to zero "ECX"? >> >> Thanks, >> Ray >>> -----Original Message----- >>> From: Kinney, Michael D > >>> Sent: Friday, January 19, 2024 7:11 AM >>> To: Tom Lendacky >; devel@edk2.groups.io; >>> Gao, Liming >; Liu, Z= higuang >> >; >>> Dong, Eric >; Ni, Ray <= ray.ni@intel.com>; Kumar, >> Rahul R >>> >; Gerd Hoffman= n >; Ard >>> Biesheuvel = > >>> Cc: Michael Roth >; K= inney, Michael D >>> > >>> Subject: RE: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use >>> AsmCpuidEx() for CPUID_EXTENDED_TOPOLOGY leaf >>> >>> Hi Tom, >>> >>> I do not see any harm in zeroing ECX in AsmCpuid(). >>> >>> If it is not zeroed, then it would have an undefined value. >>> >>> However, calling AsmCpuid() for any Index that evaluates ECX >>> (including a check for 0) should never be done. If ECX is >>> evaluated for a given Index, then AsmCpuIdEx() must be used. >>> >>> Mike >>> >>>> -----Original Message----- >>>> From: Tom Lendacky > >>>> Sent: Wednesday, January 17, 2024 1:26 PM >>>> To: devel@edk2.groups.io; Kinney, Michael= D >>>> >; Gao, = Liming >; >> Liu, >>>> Zhiguang >; Dong= , Eric >; >> Ni, >>>> Ray >; Kumar, Rahul R >; >> Gerd >>>> Hoffmann >; Ard Biesheuvel >>> > >>>> Cc: Michael Roth > >>>> Subject: Re: [edk2-devel] [PATCH 1/2] UefiCpuPkg/MpInitLib: Use >>>> AsmCpuidEx() for CPUID_EXTENDED_TOPOLOGY leaf >>>> >>>> On 11/28/23 08:35, Lendacky, Thomas via groups.io wrote: >>>>> On 11/6/23 17:15, Tom Lendacky wrote: >>>>>> On 11/6/23 16:45, Lendacky, Thomas via groups.io wrote: >>>>>>> The CPUID_EXTENDED_TOPOLOGY CPUID leaf takes a subleaf as input >>> when >>>>>>> returning CPUID information. However, the AsmCpuid() function >> does >>>> not >>>>>>> zero out ECX before the CPUID instruction, so the input leaf is >> used >>>> as >>>>>>> the sub-leaf for the CPUID request and returns erroneous/invalid >>>> CPUID >>>>>>> data, since the intent of the request was to get data related to >>>> sub-leaf >>>>>>> 0. Instead, use AsmCpuidEx() for the CPUID_EXTENDED_TOPOLOGY >> leaf. >>>>>> >>>>>> Alternatively, the AsmCpuid() function could be changed to XOR >> ECX >>>>>> before invoking the CPUID instruction. This would ensure that the >> 0 >>>>>> sub-leaf is returned for any CPUID leaves that support sub- >> leaves. >>>>>> Thoughts? >>>>>> >>>>>> Adding some additional maintainers for their thoughts, too. >>>>> >>>>> Any thoughts on this approach (as a separate, unrelated patch) to >>>>> eliminate future issues that could pop up? >>>>> >>>>> Seems like zeroing out ECX before calling CPUID would be an >>>> appropriate >>>>> thing to do, but I'm not sure if that will have any impact on the >>>> existing >>>>> code base... it shouldn't, but you never know. >>>> >>>> Just a re-ping for thoughts on this. >>>> >>>> Thanks, >>>> Tom >>>> >>>>> >>>>> Thanks, >>>>> Tom >>>>> >>>>>> >>>>>> Thanks, >>>>>> Tom >=20 >=20 >=20 >=20 >=20 >=20 -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#114117): https://edk2.groups.io/g/devel/message/114117 Mute This Topic: https://groups.io/mt/102432782/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-