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 X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 150AAC47095 for ; Wed, 9 Jun 2021 05:52:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3349610A5 for ; Wed, 9 Jun 2021 05:52:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233116AbhFIFxz (ORCPT ); Wed, 9 Jun 2021 01:53:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:58140 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232671AbhFIFxx (ORCPT ); Wed, 9 Jun 2021 01:53:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623217919; 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=zBlO5SUlBu4kEPbM4S2HV+BFWwYYvZMzotDUfmY4wqk=; b=KJ4razBWiMTFqlx63bJlGM5k5phL2AowQxKHuVmtWWdhSPlBl6snipK/NvFWjLXnDRjJuH 0ha10vhvZ/DldI/ViIJcIps1a6TmU2Wpq1lJXgxJmovJ56NoU3ESk/DV5oCJanA8SB7IRb V2yPX4QeK6Drd3h+aOntOLDSAV5aPgg= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-593-3G0MkxqsM9qMNkVPo_qWyg-1; Wed, 09 Jun 2021 01:51:57 -0400 X-MC-Unique: 3G0MkxqsM9qMNkVPo_qWyg-1 Received: by mail-wr1-f69.google.com with SMTP id r17-20020a5d52d10000b0290119976473fcso8090994wrv.15 for ; Tue, 08 Jun 2021 22:51:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=zBlO5SUlBu4kEPbM4S2HV+BFWwYYvZMzotDUfmY4wqk=; b=Rl4T0aIDRfnwathwPqX13CM4AjtH98xT41UniIXSfZSLaMTgx4JZn8kSCn1FpfnFfP CjR3+J2hSrtjjPnjtF1oGWF7/aHYeJwVcntwEzowLAmCXH3/Mhe2h+y3x1r7xmUqDcJj 52ckUdwGFjFcaw4afg76BKsUnVUuqkJ2C0CxukAqkJFQDVG21zxvb/K8rdYTKJryv05S ptdSWimhOGdlWpruVzScOuyR3NrRD4lngynYvb29FMZ/jgrJ+b6hJYZdY43nnZqoTNsO ks1LBZCQf/zpw/MKABSnz7iXv9uYJVZgS8gMniLcBciSMik83V9RJTMFQ+nnObOUHufz xEnw== X-Gm-Message-State: AOAM531yc+lzLmU5R2DIskRch8uNnH11zndZNI6KGklE8kwVSQDv8L08 HFNJdHzmwQDJ3HnAygespNFCLxwDCK25TT7VoMH2eaAej7FByCfX372x/WRJjaAhYJnVoInIPRG SzbtWRv8ohuy7gAf8FwsxLzpT X-Received: by 2002:a5d:568a:: with SMTP id f10mr3117916wrv.252.1623217916626; Tue, 08 Jun 2021 22:51:56 -0700 (PDT) X-Google-Smtp-Source: ABdhPJypZdy0ngsECXPmFiGY62B4hG9MP8f4LPp2rJ41kW29cDiE/x+WYEv9GMwZIqgrB1AiNqiaig== X-Received: by 2002:a5d:568a:: with SMTP id f10mr3117897wrv.252.1623217916423; Tue, 08 Jun 2021 22:51:56 -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 o20sm4700490wms.3.2021.06.08.22.51.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 08 Jun 2021 22:51:55 -0700 (PDT) Subject: Re: [PATCH v2 2/3] KVM: LAPIC: Reset TMCCT during vCPU reset To: Wanpeng Li Cc: LKML , kvm , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel References: <1623050385-100988-1-git-send-email-wanpengli@tencent.com> <1623050385-100988-2-git-send-email-wanpengli@tencent.com> <0584d79d-9f2c-52dd-5dcc-beffd18f265b@redhat.com> From: Paolo Bonzini Message-ID: Date: Wed, 9 Jun 2021 07:51:54 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/06/21 04:15, Wanpeng Li wrote: > On Wed, 9 Jun 2021 at 00:27, Paolo Bonzini wrote: > [...] >> Perhaps instead set TMCCT to 0 in kvm_apic_set_state, instead of keeping >> the value that was filled in by KVM_GET_LAPIC? > > Keeping the value that was filled in by KVM_GET_LAPIC is introduced by > commit 24647e0a39b6 (KVM: x86: Return updated timer current count > register from KVM_GET_LAPIC), could you elaborate more? :) KVM_GET_LAPIC stores the current value of TMCCT and KVM_SET_LAPIC's memcpy stores it in vcpu->arch.apic->regs. KVM_SET_LAPIC perhaps could store zero in vcpu->arch.apic->regs after it uses it, and then the stored value would always be zero. Paolo