From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from new2-smtp.messagingengine.com (new2-smtp.messagingengine.com [66.111.4.224]) by dpdk.org (Postfix) with ESMTP id 621A4DE3 for ; Fri, 3 Nov 2017 14:05:18 +0100 (CET) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailnew.nyi.internal (Postfix) with ESMTP id CBBDBF8C; Fri, 3 Nov 2017 09:05:16 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute1.internal (MEProxy); Fri, 03 Nov 2017 09:05:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fridaylinux.org; h=cc:content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=LmLe6362gJCJL/8WGgkNTGVIY+l5dEOh8BWgWFFd2pg=; b=Y+ruSTep ivg6K47EDiK9zyZSt4uqv2EWlbDFAHiGSq9CEvPQ3b0WSAoy7hgAKA8uk+7eLNxv 4ti99IuK2g2Cj/OLqSkKwTfFaGjbVBKlKPW/KdPJt57VxoJLufVIhb41x4qFCK0w qae31BTRiXNhRbZwJG8oJJBSVjLMsfOO8za+nXqaypwVWlYT2lvM0tmpayAkfYqk ppiXZd1CuPvyRO8anKu8CJCzchMwKVesNgyBSWbOHL1jZJ422NgnHG6eVRSSXvjZ na8mWrhuvUQFjJBmhTzHJOiTrTPiVIUpS/FXfWTIHHwIbgy2oe3ZbXE/Trk02Rjj B0nNZGI1wfl1rw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=fm1; bh=LmLe6362gJCJL/8WGgkNTGVIY+l5d EOh8BWgWFFd2pg=; b=GUJCR6swALna1e9FNZg0h+4hM30YNwgE+ccABEns6CZnn 2aZRMjzeGTOse35L2Z1irDCBMgswRvhXnfD5St+rfx7yybAHdlMZ4E4Pa2rEd9Uw y+H2qMw1IRJ8wfFXvvfr5AZVStP2loaJzAytPD1YtspePFW3DSAI/L6HctQaumka 5MscAz6gCsGZGvYwYxzNaX+5SFd02FtUjvkizweTO24S6xJenXE/RMkaS4vr1O5i USbXaZSe8Fayxt2kg8T9XRZMUVTvck2YWLePK7XWNp5H9lLQNvt9Gx7NIa16CC7/ ixLfzMZ7RllFO+V8pG8SUWFMVLBh7lcSS4nfQuMWg== X-ME-Sender: Received: from yliu-home (unknown [222.64.174.215]) by mail.messagingengine.com (Postfix) with ESMTPA id 8517A240B2; Fri, 3 Nov 2017 09:05:15 -0400 (EDT) Date: Fri, 3 Nov 2017 21:05:11 +0800 From: Yuanhan Liu To: Maxime Coquelin Cc: "Kavanagh, Mark B" , "dev@dpdk.org" , "Horton, Remy" , "Bie, Tiwei" , "mst@redhat.com" , "jfreiman@redhat.com" , "vkaplans@redhat.com" , "jasowang@redhat.com" , "Mcnamara, John" , "Loftus, Ciara" , "Stokes, Ian" , Thomas Monjalon Message-ID: <20171103130510.GB12931@yliu-home> References: <20171005083627.27828-1-maxime.coquelin@redhat.com> <20171005083627.27828-2-maxime.coquelin@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Subject: Re: [dpdk-dev] [PATCH v3 01/19] Revert "vhost: workaround MQ fails to startup" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Nov 2017 13:05:18 -0000 On Thu, Nov 02, 2017 at 10:40:26AM +0100, Maxime Coquelin wrote: > >Moving from QEMU v2.7.0 to v2.10.0 resolves the issue. However, herein lies the issue: QEMU v2.10.0 was only released in August of this year; anecdotally, we know that many OvS-DPDK customers use older versions of QEMU (typically, v2.7.0), and are likely un[able|willing] to move. With this patch, a hard dependency on QEMU v2.10 is created for users who want to use the vHU multiq feature in DPDK v17.11 (and subsequently, the upcoming OvS v2.9.0), which IMO will likely be unacceptable for many. > > Do you mean that upstream Qemu v2.7.0 is used in production? > I would expect the customers to use a distro Qemu which should contain > relevant fixes, or follow upstream's stable branches. > > FYI, Qemu v2.9.1 contains a backport of the fix. > > >One potential solution to this problem is to introduce a compile-time option that would allow the user to [dis|en]able the VHOST_USER_PROTOCOL_F_REPLY_ACK feature - is that something that would be acceptable to you Maxime? > > Yes, that's one option, but: > 1. VHOST_USER_PROTOCOL_F_REPLY_ACK enabled should be the default > 2. VHOST_USER_PROTOCOL_F_REPLY_ACK disabled will be less extensively > tested. > > Yuanhan, what do you think? My suggestion is to still disable it by default. Qemu 2.7 - 2.9 (inclusive) is a pretty big range, that I think quite many people would hit this issue. --yliu