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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 96972ECAAD8 for ; Thu, 22 Sep 2022 21:53:39 +0000 (UTC) Received: from localhost ([::1]:37538 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1obU8Y-000505-Qg for qemu-devel@archiver.kernel.org; Thu, 22 Sep 2022 17:53:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37690) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1obU7u-0004Kr-Fv for qemu-devel@nongnu.org; Thu, 22 Sep 2022 17:52:58 -0400 Received: from mail-pl1-x636.google.com ([2607:f8b0:4864:20::636]:37639) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1obU7s-0007DF-QO for qemu-devel@nongnu.org; Thu, 22 Sep 2022 17:52:58 -0400 Received: by mail-pl1-x636.google.com with SMTP id d24so10067582pls.4 for ; Thu, 22 Sep 2022 14:52:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :sender:from:to:cc:subject:date; bh=if6bmvSKsaBnNIktSsr9BygGiOGPcZLK2+qPWQY+I8Q=; b=pzrzZoZsjTwq0XNe56drHDqsxDp7gBfWdPbWC4rt2H5R39L+OGEj+zrr5t8Mq4IrxG Mt2/nnh5zDrJXCq8HjPdFJP3E/0LhfQs+UXWmpMiECR63NhfhMOCNbi3qC1lxT2g3nSb QtTAwyEe8SkY+f5ojGLzR8Mvfd/9lqBzpoqMjw0fiGZe7+ZZNwvv9B1TOtxBiBIpAXA1 ZNUBxoSVtsIjhMdk30I3D67vJrsVP7294xM1/d7kPETtmPiK2ny5Wx0Kx6kbgE85MxH+ y/rql3TyAvj5tXH6wvmJvMbHyEEXB3UNdN8R6B07ZEiIVzoAAdE1fwHH0PApALHIDhNO QRGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :sender:x-gm-message-state:from:to:cc:subject:date; bh=if6bmvSKsaBnNIktSsr9BygGiOGPcZLK2+qPWQY+I8Q=; b=PzbDia/4Vuv+1DTYuzaCpovfqMa9ybaJm0vCroam+M/h1LM5xDLeNR+Fmj+NHakrBl wqGUxzRCq8QjW0OWbfdXiE74gIsZU2Mr3gDA+K0zvSRvOEGIx0/Bn7bp/0DBe1tA97ss 3GlILfKWyZYTzoUz86rT1Kt+MrFiKawrQL/Aq+ex8c4JB3Aj7enwfh1TY0syu83pXHUr Xn27ICpt1ZmC28pTVgiRIVlEE1Hs7Hat+7tBlQfrRAaByI98gdLvNQen14idVBXOtX4Y n3EMIshSzMzewalTuruU6KyTtM9jAJFPSGr/0j1okj4SSjcdNhKFnCU5CcCIm0h/FKLV oR1A== X-Gm-Message-State: ACrzQf2SXGsZjYDbsO5br60BiIQ+w9kWqK6Wtlts72OSD85w+lApeYVP wzuYvNO/ETIbK0AgD9OroZ8= X-Google-Smtp-Source: AMsMyM61hHVf6UplTn/7JYhhc7r+rMhb8XpkmmQ+vVzd3yKOgiQoftY3FYHMhBk81gBJikhJGcIwfQ== X-Received: by 2002:a17:90b:3b92:b0:203:a4c6:383c with SMTP id pc18-20020a17090b3b9200b00203a4c6383cmr5834697pjb.92.1663883575325; Thu, 22 Sep 2022 14:52:55 -0700 (PDT) Received: from [192.168.1.115] ([185.126.107.38]) by smtp.gmail.com with ESMTPSA id a27-20020aa794bb000000b0052dbad1ea2esm4927259pfl.6.2022.09.22.14.52.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 22 Sep 2022 14:52:54 -0700 (PDT) Message-ID: <3220202f-40d4-fe47-d521-a804614d9390@amsat.org> Date: Thu, 22 Sep 2022 23:52:51 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.13.1 Subject: Re: [PATCH] KVM: dirty ring: Add memory barrier when marking pfn collected Content-Language: en-US To: Peter Xu , qemu-devel@nongnu.org Cc: Marc Zyngier , Gavin Shan , Paolo Bonzini References: <20220922213522.68861-1-peterx@redhat.com> In-Reply-To: <20220922213522.68861-1-peterx@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::636; envelope-from=philippe.mathieu.daude@gmail.com; helo=mail-pl1-x636.google.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, NICE_REPLY_A=-1.893, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Reply-to: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= via On 22/9/22 23:35, Peter Xu wrote: > Following commit 4802bf910eee9, add the other missing barrier when marking > the PFN as collected. This will also be required just like 4802bf910eee9 > on weak ordering architectures like aarch64. > > Cc: Marc Zyngier > Cc: Gavin Shan > Cc: Paolo Bonzini > Signed-off-by: Peter Xu > --- > accel/kvm/kvm-all.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 136c8eaed3..60a044048e 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -728,7 +728,11 @@ static bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn) > > static void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn) > { > - gfn->flags = KVM_DIRTY_GFN_F_RESET; > + /* > + * Write the flags after reading the entry. Should pair with another > + * smp_load_acquire() in KVM when reset dirty rings. > + */ > + qatomic_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET); > } > > /* Reviewed-by: Philippe Mathieu-Daudé