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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A52AC433F5 for ; Tue, 10 May 2022 14:05:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244795AbiEJOJo (ORCPT ); Tue, 10 May 2022 10:09:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245364AbiEJOJ1 (ORCPT ); Tue, 10 May 2022 10:09:27 -0400 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50481B7E4 for ; Tue, 10 May 2022 06:43:46 -0700 (PDT) Received: by mail-pf1-x429.google.com with SMTP id x52so14978904pfu.11 for ; Tue, 10 May 2022 06:43:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=no4knFj2QkkG24w5BpGtHthRtUO1MTUEciG91xe028g=; b=fTLJckD+LdKD21kXVmiJtp60Iev8s/1LA8KcxKZqvHWZt7LbRid5lQbpzOVFixyRXr 6c/SwjoaijWHCa/cY11vzsye30v95o28+AKDT9eb5rYsxBcX744c4SCq0nnH50Vptu6c OpXcz3VbtQnJ9BdmNn5OyRBrspO7m6Hc+3PzVFhbrKuhnAEofJABBFoU0Nfo4nBhAckN 57+R+5GIZT/KIob/+juDeGfCbhwUvXqF8/ugGVejcy4wfHysUBRMAZjXcvayfsFee8pT 5ocBjrR5QgsGbfjWCD4I/IUhu4iAM+5Gad4aEIO4+gjq7ZkI+pATFyfYiom9Zsme11JS Hs/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=no4knFj2QkkG24w5BpGtHthRtUO1MTUEciG91xe028g=; b=fGiDwn0iyJdB4guUh4QrZc8/A59Tw0H5SV5Kyotfo0qrAetoiifG6OeLw2ySfSvX8+ 7Q0ZTpdCrYIJ5x5iq/MQ/xuP60o2X9954iUrRBjnArdkS9DrpKiywx+xFzekHUzqIxD0 t9iiWa3nT4iR7nQCHjWzv4FX1YEUK2DgAcPJIwqTxKIQn/1bARre4fUGosZnU0ModNRS IUZY9pyAgP6GNvSr/qwq0Szc3HHL4d+ofvx+6n/gDw1jOfacT5HQQPUfqgj818enwNFW HyYPt2WyZfOMJoFFWWXWMFNTV6NAWWIcTjevxbCAc49NejZQ7t/YER8vlATXMrcSzyOX 8cjQ== X-Gm-Message-State: AOAM530dZo6RZ6+7i0HQdlLd6eUl+rKogDfJXq76BT1YIXxKtuuyAOUh DLunWFL+Mt6Gs9mtJfXOtf1vUA== X-Google-Smtp-Source: ABdhPJyOopUd0tEn4NWLvw+TLQgnEqGNe3teQaVnB3OwAvTVYOpo3ul4fVGXJ+cPKtzzJYqEczgAAw== X-Received: by 2002:a63:d504:0:b0:3c6:ab6b:fd2b with SMTP id c4-20020a63d504000000b003c6ab6bfd2bmr9333333pgg.437.1652190225544; Tue, 10 May 2022 06:43:45 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id o20-20020a635a14000000b003c5e836eddasm10175398pgb.94.2022.05.10.06.43.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 May 2022 06:43:45 -0700 (PDT) Date: Tue, 10 May 2022 13:43:41 +0000 From: Sean Christopherson To: Wanpeng Li Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: Re: [PATCH] KVM: LAPIC: Disarm LAPIC timer includes pending timer around TSC deadline switch Message-ID: References: <1652175386-31587-1-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1652175386-31587-1-git-send-email-wanpengli@tencent.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, May 10, 2022, Wanpeng Li wrote: > From: Wanpeng Li > > The timer is disarmed when switching between TSC deadline and other modes, > however, the pending timer is still in-flight, so let's accurately set > everything to a disarmed state. > > Fixes: 4427593258 (KVM: x86: thoroughly disarm LAPIC timer around TSC deadline switch) > Signed-off-by: Wanpeng Li > --- > arch/x86/kvm/lapic.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index 66b0eb0bda94..0274d17d91c2 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1562,6 +1562,7 @@ static void apic_update_lvtt(struct kvm_lapic *apic) > kvm_lapic_set_reg(apic, APIC_TMICT, 0); > apic->lapic_timer.period = 0; > apic->lapic_timer.tscdeadline = 0; > + atomic_set(&apic->lapic_timer.pending, 0); What about doing this in cancel_apic_timer()? That seems to be a more natural place to clear pending. It's somewhat redundant since the other two callers of cancel_apic_timer() start the timer immediately after, i.e. clear pending anyways, but IMO it's odd to leave pending set when canceling the timer. > } > apic->lapic_timer.timer_mode = timer_mode; > limit_periodic_timer_frequency(apic); > -- > 2.25.1 >