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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83980C433EF for ; Tue, 2 Nov 2021 17:02:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6273560232 for ; Tue, 2 Nov 2021 17:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234571AbhKBREi (ORCPT ); Tue, 2 Nov 2021 13:04:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49447 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231725AbhKBREh (ORCPT ); Tue, 2 Nov 2021 13:04:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635872522; 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; bh=B/7JyvbnmgvalQJYsoo2YThhI+3HlX8yusZmkgIWHPk=; b=cwlG5YU04n/+cDeLxDoyM5CiZS24im04aVRHv7OtckgNpzDNUjY0bJMQtZz90VK/ebI1Sb ZFXLL2QVZRiE5o/oaqY2bcslwNw11o08D24xCxjCq14nE0GNwHihMPc5aNz3xykG5tdD+o 27bnMd7emEtv/OiaAPVHWSqkLfk73zA= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-506-uZD0vfU9M1mdOFrI_ahwDg-1; Tue, 02 Nov 2021 13:02:01 -0400 X-MC-Unique: uZD0vfU9M1mdOFrI_ahwDg-1 Received: by mail-wr1-f71.google.com with SMTP id d13-20020adf9b8d000000b00160a94c235aso7622958wrc.2 for ; Tue, 02 Nov 2021 10:02:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=B/7JyvbnmgvalQJYsoo2YThhI+3HlX8yusZmkgIWHPk=; b=LAuFkunTNWtREKVDICuy8nqJsKXrTwfHPyCBIXKE+lieZN8HT/P+b9TfZ+9QbyBL9S DJ5vNtajdL3oeZEl/mCTZdsZu1hJqjXhkWSLcT/2TigJYRVRs0tcbrO37CC/i8lsxKXy inx10C1cMwrgpkdjkS0mPC9xOck/Ut6E6iVfUfDlI3FnKmWbU8mlMI+Equx6hgQfV6QV v/TS66pf1FWEA6xUxh3Sfg3lBIuQer/AJpKP2KX4Ago8m+fP/SZtz1w/J2Mayb32QfFl vhnAIhHRp1RzPD0InVXf70JErvd67Wv9Ur0zuaVObERrzZXxGiKxShpSVgJ8lPp6C6gl Hl5g== X-Gm-Message-State: AOAM531sqxV1c9temv50Gwyc6C2ZQzvs5kqRPLJMSCDcfMafbrR4nOXQ BYa4rJ0qd66lt5VdU7bSmeHQ9LPwirGl1NWH0iJKJk4fTXWFEJNRPKFnfUh2x+69+k5mSdcX7LG v+tKdtLNAm7ha X-Received: by 2002:a05:600c:1c07:: with SMTP id j7mr8883631wms.12.1635872520062; Tue, 02 Nov 2021 10:02:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxk599EiV+NQhEhQXSyCoVvxdWsetYXFy0uivu7bXS8uyuAq3spW6vcffFx2C05Nsqz5WlLdQ== X-Received: by 2002:a05:600c:1c07:: with SMTP id j7mr8883591wms.12.1635872519724; Tue, 02 Nov 2021 10:01:59 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id q14sm17311754wrr.28.2021.11.02.10.01.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 02 Nov 2021 10:01:59 -0700 (PDT) Message-ID: <624bc910-1bec-e6dd-b09a-f86dc6cdbef0@redhat.com> Date: Tue, 2 Nov 2021 18:01:56 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: [PATCH v2] KVM: x86: Fix recording of guest steal time / preempted status Content-Language: en-US To: David Woodhouse , kvm Cc: Boris Ostrovsky , Joao Martins , "jmattson@google.com" , "wanpengli@tencent.com" , "seanjc@google.com" , "vkuznets@redhat.com" , "mtosatti@redhat.com" , "joro@8bytes.org" , karahmed@amazon.com References: <5d4002373c3ae614cb87b72ba5b7cdc161a0cd46.camel@infradead.org> <4369bbef7f0c2b239da419c917f9a9f2ca6a76f1.camel@infradead.org> From: Paolo Bonzini In-Reply-To: <4369bbef7f0c2b239da419c917f9a9f2ca6a76f1.camel@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 02/11/21 17:38, David Woodhouse wrote: > This kind of makes a mockery of this > repeated map/unmap dance which I thought was supposed to avoid pinning > the page The map/unmap dance is supposed to catch the moment where you'd look at a stale cache, by giving the non-atomic code a chance to update the gfn->pfn mapping. The unmap is also the moment where you can mark the page as dirty. Paolo