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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 7B917C54EE9 for ; Mon, 19 Sep 2022 16:18:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=VHv5793WognBnUBaiCPVPm+HKvoZfnbo9d0arGzOU6w=; b=eWLXiKaVdBuYN8 Zs+s3V6mc5ARpgj5jZu/zlLjoL/+AOM3S7h1Ptl15HZX4L+r9F3UwT4rmbQoccD+7MyYlAaATqq1C 9haffqYzMdrHyfID3wPXv8UpKDvItQmTQmo9UDnDr3GIbkD6jT+HKtEh7yJeob2XJcPvHBvvjzBxr rigw4pVq+C+QwMqclKeE48ojdUNR/4iRk1U+DnOCstnDEZiSOQrFmfiRnOAz/YgJbWrIuyLChqM9P IxkE/ZlVAXzOnogYEX8p3pIPm4ZwydfI2cqywTdpW2mmwtGdecqAIGcJw/fA6XgwR/D5+Nlr+MkZG neSqCc2SRHJrOb+J9Xow==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oaJSO-00CokS-7x; Mon, 19 Sep 2022 16:17:16 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oaJSK-00CohN-E0 for linux-arm-kernel@lists.infradead.org; Mon, 19 Sep 2022 16:17:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663604228; 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: in-reply-to:in-reply-to:references:references; bh=Xn5fnqKtyryYA5w5sfE3wIiUTcmcdDi6qpfcSbkJ4Lw=; b=WQAzY7699v2Xk0UJmkLi7Xq9XAajw9ItQSHv3ju/69ODi7qwPrECoLd7/4wVAnH/kD+HwW Wbn8tCi/vdNng11IkARY9JRFK36cf2UiMoM6B5DXQojC3d/y5UwsKQryl3BE/YUTTds7vq +R1139y9pN/eUcLyfit2nqvvDmU1m6s= Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-228-dFqw2RXDMqqanv2uLfH81A-1; Mon, 19 Sep 2022 12:17:05 -0400 X-MC-Unique: dFqw2RXDMqqanv2uLfH81A-1 Received: by mail-qt1-f199.google.com with SMTP id w4-20020a05622a134400b0035cbc5ec9a2so10517497qtk.14 for ; Mon, 19 Sep 2022 09:17:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date; bh=Xn5fnqKtyryYA5w5sfE3wIiUTcmcdDi6qpfcSbkJ4Lw=; b=YnSbYt89uqH1j9zZea0kSLd01KroikLwMlVJKqHsiIfWD/o4JUvye6/u6q1ROSOK6F kixqQcvDAobuEUKHyd9iNpGMmzKndhk2oHEncxiY+VjqRV7PeXqukIXvobl1njM1oR/o N33pcHJdFuzDwTWbNTDCPbGiYUYvmdInbVzx/scxp2H5fbe5dytUWHeuFXlTtBr+E6vT j1ud7Z6ZpOi3YNDulSJ9qB2GNKxQl3mGIC5r0sGwCYkknI1Eu46R4YG7cPJ31cpEfyIL sgI6n/UsSzzfTju2zFxoUW0Mn0DpgcoyfwPmyeXu9qF/JVMi0tCGeGd/d6/LKM9OUpVs mroA== X-Gm-Message-State: ACrzQf1iUPuJ9Jir1h1nKQ035hTyycWOHDRniBYBpHvsd3nsdWIRetmF BsTYPZcCBZt4Lm9LtOoj6pZX689SUFm1bV8U+YweCUcemiNZV0TwEhxO9Q/BlHsdPGGsUTKAW1+ oFFAyWJYZzCw59QDoiexHCqDZ68ia6tViIJE= X-Received: by 2002:ac8:5e0a:0:b0:35c:e8d8:6c19 with SMTP id h10-20020ac85e0a000000b0035ce8d86c19mr5068673qtx.178.1663604225353; Mon, 19 Sep 2022 09:17:05 -0700 (PDT) X-Google-Smtp-Source: AMsMyM51+LmYDmB5JjErlr4hYbacMbbiBwggTg81wkAjJVlWGP8agHsUu4S5cY7WS6QJw0cvQ6qJIg== X-Received: by 2002:ac8:5e0a:0:b0:35c:e8d8:6c19 with SMTP id h10-20020ac85e0a000000b0035ce8d86c19mr5068640qtx.178.1663604225144; Mon, 19 Sep 2022 09:17:05 -0700 (PDT) Received: from xz-m1.local (bras-base-aurron9127w-grc-46-70-31-27-79.dsl.bell.ca. [70.31.27.79]) by smtp.gmail.com with ESMTPSA id bv12-20020a05622a0a0c00b0035cf2995ad8sm826570qtb.51.2022.09.19.09.17.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Sep 2022 09:17:04 -0700 (PDT) Date: Mon, 19 Sep 2022 12:17:02 -0400 From: Peter Xu To: Gavin Shan Cc: Marc Zyngier , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-doc@vger.kernel.org, catalin.marinas@arm.com, linux-kselftest@vger.kernel.org, bgardon@google.com, shuah@kernel.org, corbet@lwn.net, drjones@redhat.com, will@kernel.org, zhenyzha@redhat.com, dmatlack@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, oliver.upton@linux.dev, shan.gavin@gmail.com Subject: Re: [PATCH v2 1/5] KVM: x86: Introduce KVM_REQ_RING_SOFT_FULL Message-ID: References: <20220916045135.154505-1-gshan@redhat.com> <20220916045135.154505-2-gshan@redhat.com> <87illlkqfu.wl-maz@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220919_091712_586590_51E9AE86 X-CRM114-Status: GOOD ( 11.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Sep 19, 2022 at 09:58:10AM +1000, Gavin Shan wrote: > I think Marc's explanation makes sense. It won't make difference in terms > of performance. We need to explicitly handle barrier when kvm_test_request() > is used. So I prefer to keep the code if Peter agrees. No strong opinion here. I keep thinking clear+set look awkward even if it's unlikely path to trigger (ring should be recycled when reaching here for any sane user app), but if it's already 2:1 then please go ahead. :) Thanks, -- Peter Xu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel