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 184D3E7D0A9 for ; Thu, 21 Sep 2023 19:59:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229939AbjIUT76 (ORCPT ); Thu, 21 Sep 2023 15:59:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231284AbjIUT7Q (ORCPT ); Thu, 21 Sep 2023 15:59:16 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2908846DDC for ; Thu, 21 Sep 2023 10:24:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695317055; 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=A/UaA3dwsjl/5n39ZInDe8A7bNv9U9kL0fxecQB4u1g=; b=AwtkSQyr5dmgV2dRXwKtdgryW0l72rgfQvOsvkZS9D0jtOISQHeEue6a1bNmyZ4KQWkM4Y 1+4rUJBWukkXMdGQCQ2pLquSOZMYD6KiD/7NI9AeV18h12Z2nUwama7kkrFbIwpc8YB0DA zN3PXg4acCqA/HHXdf18M7nJiMigMX8= Received: from mail-lj1-f198.google.com (mail-lj1-f198.google.com [209.85.208.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-82-YaChpToDNTmp2kev7xaV0Q-1; Thu, 21 Sep 2023 13:24:13 -0400 X-MC-Unique: YaChpToDNTmp2kev7xaV0Q-1 Received: by mail-lj1-f198.google.com with SMTP id 38308e7fff4ca-2bffd454256so16854351fa.1 for ; Thu, 21 Sep 2023 10:24:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695317052; x=1695921852; 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 :message-id:reply-to; bh=A/UaA3dwsjl/5n39ZInDe8A7bNv9U9kL0fxecQB4u1g=; b=prQSWbSkh//OezB+JlBEWuuvZGA/OLycNpj/5S/XbyIT0oOS1PFgA0V+QfLiBmRCUg M7Ho7DevDwmMVWmV4vmXTnECqpRL/lbJz8oVpWxgtuPvBfkAQYI4VAtaFwSNnFLMk4MG hKK1s6qEh7w1TqUW3RlQl4q2Lv4Ebxv2M9BLqgwY1AgmnHwpFUM3vbXrn3aUHaL5H+OO 0fagnLxJRkkUqVUjo3nk1tOSbxe8XrzYvwCyW1pM7hifEn499aLVXpCJ49FnuS++6R1O /fQjYX+DCNcVPUtDAp48PStkwWJNrMA7PM2aNjfojjQadnjXdfE7MywimwDBRGBiLUVi /AMQ== X-Gm-Message-State: AOJu0Yye42+6Zd0opxABaQuCZ1Nw/rDfOh8uEUsKKimZpNCLyhyerDek cEDJiglmG1pRnnpZKf5YSXhuQ8lHW3l0Xg8CdPybhg5AcXDumfUCuOoNKB9iRz03EdqyCHDuF/k Z2z7spGpjTzab X-Received: by 2002:a2e:7a15:0:b0:2c0:18b8:9656 with SMTP id v21-20020a2e7a15000000b002c018b89656mr5417401ljc.24.1695317052275; Thu, 21 Sep 2023 10:24:12 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGuyY22Pu4JJbcepqQfut19xS8d93zqlgBqv3AjWx+BgTUEs/dbdgGpZwmKYhhDDtmusapHPw== X-Received: by 2002:a2e:7a15:0:b0:2c0:18b8:9656 with SMTP id v21-20020a2e7a15000000b002c018b89656mr5417379ljc.24.1695317051939; Thu, 21 Sep 2023 10:24:11 -0700 (PDT) Received: from redhat.com ([2.52.150.187]) by smtp.gmail.com with ESMTPSA id p26-20020a170906229a00b009ad8338aafasm1380250eja.13.2023.09.21.10.24.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Sep 2023 10:24:11 -0700 (PDT) Date: Thu, 21 Sep 2023 13:24:07 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: Jason Gunthorpe , Alex Williamson , Yishai Hadas , "jasowang@redhat.com" , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , Feng Liu , Jiri Pirko , "kevin.tian@intel.com" , "joao.m.martins@oracle.com" , Leon Romanovsky , Maor Gottlieb Subject: Re: [PATCH vfio 11/11] vfio/virtio: Introduce a vfio driver over virtio devices Message-ID: <20230921132206-mutt-send-email-mst@kernel.org> References: <20230921124040.145386-1-yishaih@nvidia.com> <20230921124040.145386-12-yishaih@nvidia.com> <20230921104350.6bb003ff.alex.williamson@redhat.com> <20230921165224.GR13733@nvidia.com> <20230921125348-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Sep 21, 2023 at 05:09:04PM +0000, Parav Pandit wrote: > > > > From: Michael S. Tsirkin > > Sent: Thursday, September 21, 2023 10:31 PM > > > Another question I'm interested in is whether there's actually a performance > > benefit to using this as compared to just software vhost. I note there's a VM exit > > on each IO access, so ... perhaps? > > Would be nice to see some numbers. > > Packet rate and bandwidth are close are only 10% lower than modern device due to the batching of driver notification. > Bw tested with iperf with one and multiple queues. > Packet rate tested with testpmd. Nice, good to know. Could you compare this with vdpa with shadow vq enabled? That's probably the closest equivalent that needs no kernel or hardware work. -- MST