From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33F83C4332F for ; Wed, 13 Dec 2023 14:18:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A583D6B0450; Wed, 13 Dec 2023 09:18:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A08396B0452; Wed, 13 Dec 2023 09:18:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 834616B04CE; Wed, 13 Dec 2023 09:18:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 70AB86B0450 for ; Wed, 13 Dec 2023 09:18:27 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 2DA7B160B6C for ; Wed, 13 Dec 2023 14:18:27 +0000 (UTC) X-FDA: 81562000254.17.3687FEE Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf08.hostedemail.com (Postfix) with ESMTP id CFF4E160022 for ; Wed, 13 Dec 2023 14:18:24 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Cwx1JGJ+; spf=pass (imf08.hostedemail.com: domain of pbonzini@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=pbonzini@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702477104; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Fws0gJvMeLr/QEe2P9D0VBdduPdR7zo8ED97N4rFNAU=; b=50Uypu4fDBWZwIk//2pFwBefPMhOrQ9M4khuFmjPTCW9ZQj7O+R9PunJFY/B26z1wIDNC1 F1yszH68r5nI4Iv9dVjsJ12RjkTh1jZagbo8zL6os079I/MkVGo1r+EATGae7IJBtrxXm4 xUlnOnaWkk7aqj6ceqosLlXTpd09vww= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702477104; a=rsa-sha256; cv=none; b=YfONLvtyiUZGT8I94INoTvtLb3nY8x3oIMCpDb4VzOMd+gYm6Ro0b6j3Bkf/WYXm26JpvL 1rZIKO22O3e5NjjzzB3C9B3Y4d2NhdE7gNzuXbDG/rczpyUcB2IKVZNpGevKqM3rL9OFJy 3N4W0ETZxU5LOEBT75V5Kca+Y+ka7Hw= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Cwx1JGJ+; spf=pass (imf08.hostedemail.com: domain of pbonzini@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=pbonzini@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702477104; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=Fws0gJvMeLr/QEe2P9D0VBdduPdR7zo8ED97N4rFNAU=; b=Cwx1JGJ+etOOL9jfEA19tblFnXXNs2XtJKygOu+GsWe+xrW3dCy10kzlDoI3sUAFEe48u6 yPDpNyD5VuSBGQaJ0JSJyBBG+LumGFC0QiilpaIO3VfWjk7LfYCB49B5sHZHBy1KGwIVaI sdgqb6VTNZQjNgviNmcyOo+Bo5BGPlY= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-557-Qw83hBLPP8aYYIKy5hERug-1; Wed, 13 Dec 2023 09:18:22 -0500 X-MC-Unique: Qw83hBLPP8aYYIKy5hERug-1 Received: by mail-ej1-f69.google.com with SMTP id a640c23a62f3a-a1cfd84b473so769387066b.1 for ; Wed, 13 Dec 2023 06:18:22 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702477102; x=1703081902; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Fws0gJvMeLr/QEe2P9D0VBdduPdR7zo8ED97N4rFNAU=; b=b6bbREzh1Bi3UasclMyadhtWu3sBI0o/mQaKsUdmoU8u0zOuDaPDJKoSWSuCWwCUxI 8ue8czAVidYbCub+ADMGkiiBHqQhy4cArjVZ9xod3mrdvf37mdKB2enPDLzG6pRWPtSr mE2A6LvFCpH1hXFfyKLWyJ9zpKG1yrtMvRoZieff0Oe3VmoF91kR8vozNHqrZ6OLUqT+ +ZGi8nRMSsYbB7Tk8tzmcg6A5QKHJBxY4yIaWXPc4e/3fGuFqjp/L9MiXIxVoVFZWYqr 3fdh3FofutAZTzwBZ8+DsrTPXAQnuMYMluWOoMpMdPZKAcWKaoNhCyEHk5peyEt0xFcL HK5A== X-Gm-Message-State: AOJu0Yyz+jMJaCHn3PRMZTTqfWwYcKTrB6IjfYyrtu4o0YGJrxJZ4miR 4KPdSa7oIlztYF/omXXdv1u/DriGhwIQGXurqyXGNNXaoK3kR33FbFy4CDn6fvGB55Ri10/D9gs 5BjHEdZ5pD1U= X-Received: by 2002:a17:906:24d:b0:a22:e7d2:5a52 with SMTP id 13-20020a170906024d00b00a22e7d25a52mr2784678ejl.71.1702477101805; Wed, 13 Dec 2023 06:18:21 -0800 (PST) X-Google-Smtp-Source: AGHT+IGrQokzT8zXusJ+hPGTT9RJ5H7cGwq+NBw1vIEMeKjoo6GUcHW4Rk0RO9/h3vuME7VBPouVjg== X-Received: by 2002:a17:906:24d:b0:a22:e7d2:5a52 with SMTP id 13-20020a170906024d00b00a22e7d25a52mr2784659ejl.71.1702477101439; Wed, 13 Dec 2023 06:18:21 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:63a7:c72e:ea0e:6045? ([2001:b07:6468:f312:63a7:c72e:ea0e:6045]) by smtp.googlemail.com with ESMTPSA id tk3-20020a170907c28300b00a1cd54ec021sm7876334ejc.57.2023.12.13.06.18.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 13 Dec 2023 06:18:20 -0800 (PST) Message-ID: Date: Wed, 13 Dec 2023 15:18:17 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 04/50] x86/cpufeatures: Add SEV-SNP CPU feature To: Borislav Petkov Cc: Michael Roth , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, seanjc@google.com, vkuznets@redhat.com, jmattson@google.com, luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com, peterz@infradead.org, srinivas.pandruvada@linux.intel.com, rientjes@google.com, dovmurik@linux.ibm.com, tobin@ibm.com, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, jarkko@kernel.org, ashish.kalra@amd.com, nikunj.dadhania@amd.com, pankaj.gupta@amd.com, liam.merwick@oracle.com, zhi.a.wang@intel.com, Brijesh Singh , Jarkko Sakkinen References: <20231016132819.1002933-1-michael.roth@amd.com> <20231016132819.1002933-5-michael.roth@amd.com> <0b2eb374-356c-46c6-9c4a-9512fbfece7a@redhat.com> <20231213131324.GDZXmt9LsMmJZyzCJw@fat_crate.local> <40915dc3-4083-4b9f-bc64-7542833566e1@redhat.com> <20231213133628.GEZXmzXFwA1p+crH/5@fat_crate.local> <9ac2311c-9ccc-4468-9b26-6cb0872e207f@redhat.com> <20231213134945.GFZXm2eTkd+IfdsjVE@fat_crate.local> From: Paolo Bonzini Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: <20231213134945.GFZXm2eTkd+IfdsjVE@fat_crate.local> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: rkty7a9nebhw8isupjqyzfs8mbhji1ur X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: CFF4E160022 X-Rspam-User: X-HE-Tag: 1702477104-490097 X-HE-Meta: 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 Qatq0aui 52NuOaEXC8W9VMPT+/85SAyELKRhRH0lIuP/ApFB/PXT477pboEdDeNkhpj40F9RHMDZbjmytLS8doRwdA+R4MYeujqGhsLf2NmZEXHdZOihHrlWl5tJFWCS2nxkPYqEzNq4HrAG4SfUT7qVz3g0nGU+PAr82B7TAXyMrYC4b5XIoeL91oixU4nd/eff4msDYv+fjqVvsLC+oAyTWX+OOlCVdu6r2tmeVN9/XkPKS5od6rZmzbMIkstw6EznmpLrfV/PCzNvD5aXjDUzPF0RXA2vEJ4FcBgVEgq5XyWw1gTg+rD9CC6XasckZtNM/PCYmrQyD/xn9zDaOYouwwWjgnixEFqVCBNJqy0DDzApgWRb4L9gfUC9EBH0/FgIhlWlKM6K9 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 12/13/23 14:49, Borislav Petkov wrote: > On Wed, Dec 13, 2023 at 02:40:24PM +0100, Paolo Bonzini wrote: >> Why are they dead code? X86_FEATURE_SEV_SNP is set automatically based on >> CPUID, therefore patch 5 is a performance improvement on all processors that >> support SEV-SNP. This is independent of whether KVM can create SEV-SNP >> guests or not. > > No, it is not. This CPUID bit means: > > "RMP table can be enabled to protect memory even from hypervisor." > > Without the SNP host patches, it is dead code. - if ((ia32_cap & ARCH_CAP_IBRS_ALL) || cpu_has(c, X86_FEATURE_AUTOIBRS)) { + if ((ia32_cap & ARCH_CAP_IBRS_ALL) || + (cpu_has(c, X86_FEATURE_AUTOIBRS) && + !cpu_feature_enabled(X86_FEATURE_SEV_SNP))) { Surely we can agree that cpu_feature_enabled(X86_FEATURE_SEV_SNP) has nothing to do with SEV-SNP host patches being present? And that therefore retpolines are preferred even without any SEV-SNP support in KVM? And can we agree that "Acked-by" means "feel free and take it if you wish, I don't care enough to merge it through my tree or provide a topic branch"? I'm asking because I'm not sure if we agree on these two things, but they really seem basic to me? Paolo > And regardless, arch/x86/kvm/ patches go through the kvm tree. The rest > of arch/x86/ through the tip tree. We've been over this a bunch of times > already. > If you don't agree with this split, let's discuss it offlist with all > tip and kvm maintainers, reach an agreement who picks up what and to put > an end to this nonsense. > > Thx. >