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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 627D6C352A3 for ; Thu, 13 Feb 2020 03:41:30 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 2E83B2168B for ; Thu, 13 Feb 2020 03:41:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ahgdcYN4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2E83B2168B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46946 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j25NZ-0001yj-Ds for qemu-devel@archiver.kernel.org; Wed, 12 Feb 2020 22:41:29 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33468) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j25My-0001Vo-19 for qemu-devel@nongnu.org; Wed, 12 Feb 2020 22:40:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j25Mx-0006gV-2s for qemu-devel@nongnu.org; Wed, 12 Feb 2020 22:40:51 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:38373 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j25Mw-0006dc-Vq for qemu-devel@nongnu.org; Wed, 12 Feb 2020 22:40:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581565250; 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=rLoANijvRLORZWmUnjUSah1ms3I1fKun4Z6zhHRZ0bE=; b=ahgdcYN4ddpDEIHNXTXDRq1J5Zt2CRF9vhiy9eD6o49TUkCHvlR+wge9gMK6Gc+MlKPaM9 97R4ZLsmIMdRjDWbzue6/V+w4u+jtkEwxBICuLoHy2pp2nFgYK+Zv+b4FItMsTR8vS+xO+ ZiLsXaQejLrRr7eVOx83PzKC2+6Q+WI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-301-kbzM4A79OCOj7Zb202X7AA-1; Wed, 12 Feb 2020 22:40:49 -0500 X-MC-Unique: kbzM4A79OCOj7Zb202X7AA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C33F1857345; Thu, 13 Feb 2020 03:40:47 +0000 (UTC) Received: from [10.72.13.212] (ovpn-13-212.pek2.redhat.com [10.72.13.212]) by smtp.corp.redhat.com (Postfix) with ESMTP id 044085C132; Thu, 13 Feb 2020 03:40:38 +0000 (UTC) Subject: Re: [virtio-dev] Re: [PATCH v2 4/5] virtio-mmio: add MSI interrupt feature support To: "Michael S. Tsirkin" References: <4c3d13be5a391b1fc50416838de57d903cbf8038.1581305609.git.zhabin@linux.alibaba.com> <0c71ff9d-1a7f-cfd2-e682-71b181bdeae4@redhat.com> <5522f205-207b-b012-6631-3cc77dde3bfe@linux.intel.com> <45e22435-08d3-08fe-8843-d8db02fcb8e3@redhat.com> <4c19292f-9d25-a859-3dde-6dd5a03fdf0b@linux.intel.com> <44209f3c-613c-3766-ca83-321b77b0f0dd@redhat.com> <20200212041554-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: Date: Thu, 13 Feb 2020 11:40:37 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20200212041554-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: virtio-dev@lists.oasis-open.org, Zha Bin , slp@redhat.com, "Liu, Jing2" , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, chao.p.peng@linux.intel.com, gerry@linux.alibaba.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/2/12 =E4=B8=8B=E5=8D=885:16, Michael S. Tsirkin wrote: >>> Thanks for the advice.:) >>> >>> Actually when looking into pci, the queue_msix_vector/msix_config is = the >>> msi vector index, which is the same as the mmio register MsiVecSel >>> (0x0d0). >>> >>> So we don't introduce two extra registers for mapping even in sharing >>> mode. >>> >>> What do you think? >>> >> I'm not sure I get the point, but I still prefer the separate vector_s= el >> from queue_msix_vector. >> >> Btw, Michael propose per vq registers which could also work. >> >> Thanks >> > Right and I'd even ask a question: do we need shared MSI at all? I guess it is still needed at least for the current virtio code.=20 Technically we may have thousands queues. Thanks > Is it somehow better than legacy interrupt? And why? > Performance numbers please. >