From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C0E01171C2 for ; Wed, 20 Mar 2024 09:46:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710927997; cv=none; b=G7ncHwCMYhh7T/BS0rWxX8MvpSxW1ZkdG0/vB9GhJ/rJSZsjw2zSnHX12ZJ364BB/12wYxpdSqpxoXZkK2y8JNN3P8Wcqd7Qb3NncOQnXREBKj+pYML1G11Zf26LeTfFpiYwKlJ7I/cahKEfWSFXwiyVc3h2RYWOu6FRArenjro= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710927997; c=relaxed/simple; bh=JYS75+mEXjUw09pqAXR3mKOlMrZwWFjYkegIv795lfY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KtS3beErNSiFt6miPCTVqlZs8bGwsrrS9vSe3sap52ENXfjuEnrHFJRs3WwPZptqs7SXj+eLCHIy98u2CuM8LCl/DtqAFrjre96wVk6ZeBjY0fBPNc+KSPXRR+WModraKIEdxqoByarFrpxFzhb1mBNp1VdXfrBHUV7338fmbao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=JMhPB4cB; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JMhPB4cB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710927994; 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=+WZs6qFUYItA5gvCkkHLzU1au93L0AnahHvuXruBMKk=; b=JMhPB4cBVqoI8lBYg/66fzV6bP1A9QbNE9R4NuhSs1cPUQPxoxmNKMkxSrchSIN7LR/Bco dzA67BSQDZOomVdc7V9X1ZXOLCXMq2RIYy+dgX5Itc+6r2fQF0y7hCl44T0zgH8UIuXbI8 xyrUbNVOaC6R2cQjTFkwYz+HKk9NlUo= 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-623-Tsb0pRuqMGKcpgSp6T1oXw-1; Wed, 20 Mar 2024 05:46:32 -0400 X-MC-Unique: Tsb0pRuqMGKcpgSp6T1oXw-1 Received: by mail-ej1-f69.google.com with SMTP id a640c23a62f3a-a46bae02169so71400366b.1 for ; Wed, 20 Mar 2024 02:46:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710927991; x=1711532791; 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=+WZs6qFUYItA5gvCkkHLzU1au93L0AnahHvuXruBMKk=; b=Eic9lrtjxDVjmJxXU8EY15fiqg5tlC7QwEEeNRmio8v7seY2NE0pZJHwd1n9PmS1+f 8HsYxYfK+mXdeU24XOjQwWgx+fKjsGOsUXsJ5LA5jFLjHD5m7GVMxsjQihpEhyKn4Kx0 8Yu3l7VZ4fl0mofO5eWgEenLW4/rFLbtCtN7t/xGqZKTWOwnIezsrbkY7uIJSblF/crn uVfA7lbY298edDPLa7pqEoDuxarRvq7lXCP0NIxsBysSZH8if3TSDK3YZQwQdYdl2Tlo G2nrBHY1MXSw8vr+hxcccbUkfon1nJzMghMnzS/c4Bi9BAO/ZjsmHujinAT8pCBqjkip EtsA== X-Gm-Message-State: AOJu0YyU1A/gsBjIq2z9n4UuQMRynvnaRGM9GPd2eFvxYUYzLxK1zSKW gcXg/e3/TByG0ch1+8Bv35j1RmegKsv5LDqWXANGbSpLbym22w3f8CF5Yc80Pt2KWU2O+fRR6NA 8e2gabap5cCmZ5KVyjF6Z3CC/60ZM94Dvk3blWqWnMzjWCE3CYw== X-Received: by 2002:a17:906:af8a:b0:a45:bde1:a334 with SMTP id mj10-20020a170906af8a00b00a45bde1a334mr1652428ejb.27.1710927990924; Wed, 20 Mar 2024 02:46:30 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHYWyHr39ieL8VW6sq78MqBLPco9oQ7sYS8RNzT+os3VOZljrCtsjVKViXIi+OETXikeC19vw== X-Received: by 2002:a17:906:af8a:b0:a45:bde1:a334 with SMTP id mj10-20020a170906af8a00b00a45bde1a334mr1652414ejb.27.1710927990617; Wed, 20 Mar 2024 02:46:30 -0700 (PDT) Received: from [192.168.10.118] ([151.95.49.219]) by smtp.googlemail.com with ESMTPSA id j1-20020a1709062a0100b00a46af0fbf5dsm4271330eje.103.2024.03.20.02.46.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 20 Mar 2024 02:46:30 -0700 (PDT) Message-ID: <7727f1f2-2a30-45d2-85a9-db22ec5a9be5@redhat.com> Date: Wed, 20 Mar 2024 10:46:29 +0100 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 25/49] i386/sev: Skip RAMBlock notifiers for SNP Content-Language: en-US To: Michael Roth , qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, Tom Lendacky , =?UTF-8?Q?Daniel_P_=2E_Berrang=C3=A9?= , Markus Armbruster , Pankaj Gupta , Xiaoyao Li , Isaku Yamahata References: <20240320083945.991426-1-michael.roth@amd.com> <20240320083945.991426-26-michael.roth@amd.com> 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: <20240320083945.991426-26-michael.roth@amd.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/20/24 09:39, Michael Roth wrote: > SEV uses these notifiers to register/pin pages prior to guest use, since > they could potentially be used for private memory where page migration > is not supported. But SNP only uses guest_memfd-provided pages for > private memory, which has its own kernel-internal mechanisms for > registering/pinning memory. > > Signed-off-by: Michael Roth > --- > target/i386/sev.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/target/i386/sev.c b/target/i386/sev.c > index 61af312a11..774262d834 100644 > --- a/target/i386/sev.c > +++ b/target/i386/sev.c > @@ -982,7 +982,15 @@ static int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) > goto err; > } > > - ram_block_notifier_add(&sev_ram_notifier); > + if (!sev_snp_enabled()) { > + /* > + * SEV uses these notifiers to register/pin pages prior to guest use, > + * but SNP relies on guest_memfd for private pages, which has it's > + * own internal mechanisms for registering/pinning private memory. > + */ > + ram_block_notifier_add(&sev_ram_notifier); > + } > + > qemu_add_machine_init_done_notifier(&sev_machine_done_notify); > qemu_add_vm_change_state_handler(sev_vm_state_change, sev_common); > These three lines can be done in any order, so I suggest removing ram_block_notifier_add + qemu_add_machine_init_done_notifier from the sev-common implementation of kvm_init (let's call it sev_common_kvm_init); and add an override in sev-guest that calls them if sev_common_kvm_init() succeeds. (treat this as a review for 25/26/29). Paolo