From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f178.google.com (mail-wi0-f178.google.com [209.85.212.178]) by dpdk.org (Postfix) with ESMTP id E6AFC8D3D for ; Tue, 27 Oct 2015 10:52:22 +0100 (CET) Received: by wijp11 with SMTP id p11so204973451wij.0 for ; Tue, 27 Oct 2015 02:52:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind_com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:organization:user-agent :in-reply-to:references:mime-version:content-transfer-encoding :content-type; bh=wHjjqH++4z13WUuUkuP5QGs51ADevfnJ7fAU+2EY13Y=; b=hSyyjQF0B7IWHxsSdjlvcvduw+etQEyQq2H+tMZw4OQwUNLC4N1apu7F1KkLVppfMP DleGQC4CeV2bV8A2De9VjUtRYHYjeSpXEh5q1G8iSZCl/eI/B0c16k3oyfGypDvhG6GF XN7OjLtmOGwpEi+jACxee4AWqSUcqVB3BlyEAWbgfape1o73v185InHIocIfyFZpO6kv 39p11EJS6P0V6MjC31PvZF7ihMBGDezra6NRoUvyjkZ0IitQZCRvaFE3cDOwd3ze2Y3C 6OqlZOe7jviV9mmBaN9O/AWk+g3vZc0CQjUpVwYxr9A4GSYlzYuVe87HbNrQX7/lHNyk rrYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding:content-type; bh=wHjjqH++4z13WUuUkuP5QGs51ADevfnJ7fAU+2EY13Y=; b=ipczDeY9rii6NjU291e4Ybe2PfaXbUHgQf00nUZVmvPTBvQ3gdcyvcHe9MMhSPU97F zFPdaXUwzfEoK61t72+72+TypNm0JP37ogTh/DfTxRDZy300FV3gOyheio7p0iAeFNHa tXfZiE/84hdvbfTki4jgMwjhuKQYM+fa281Si5xAviHqDEnKAa3WcEuRIrK1wGe+yyHq 1Vh/MSV8qGQgiizBBdUqzY9304nGSxTyUApTEI/4fF5OIYO7Jz/o7ZpN8g706y6mpWtW phL5poUrC279JW1+tdQOFAfzbzl3YRiAj+tq2850sCWVzj6sn+vt2HlKHXVyHmoyJjVl GEZQ== X-Gm-Message-State: ALoCoQnc94/M6bSM7v5Dm9OIuX6zzt3zo2ue7mWv6hA8nU/5wiwa/h/UYEFMbNdsoCwOppVye/qr X-Received: by 10.180.208.41 with SMTP id mb9mr23960172wic.61.1445939542715; Tue, 27 Oct 2015 02:52:22 -0700 (PDT) Received: from xps13.localnet (136-92-190-109.dsl.ovh.fr. [109.190.92.136]) by smtp.gmail.com with ESMTPSA id ec16sm9342889wic.14.2015.10.27.02.52.22 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 27 Oct 2015 02:52:22 -0700 (PDT) From: Thomas Monjalon To: "Michael S. Tsirkin" , Yuanhan Liu Date: Tue, 27 Oct 2015 10:51:14 +0100 Message-ID: <1520656.Lg374xclAN@xps13> Organization: 6WIND User-Agent: KMail/4.14.10 (Linux/4.1.6-1-ARCH; KDE/4.14.11; x86_64; ; ) In-Reply-To: <20151027113807-mutt-send-email-mst@redhat.com> References: <1445399294-18826-1-git-send-email-yuanhan.liu@linux.intel.com> <20151027093041.GI3115@yliu-dev.sh.intel.com> <20151027113807-mutt-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org, marcel@redhat.com Subject: Re: [dpdk-dev] [PATCH v8 3/8] vhost: vring queue setup for multiple queue support X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Oct 2015 09:52:23 -0000 2015-10-27 11:42, Michael S. Tsirkin: > On Tue, Oct 27, 2015 at 05:30:41PM +0800, Yuanhan Liu wrote: > > On Tue, Oct 27, 2015 at 11:17:16AM +0200, Michael S. Tsirkin wrote: > > > Looking at that, at least when MQ is enabled, please don't key > > > stopping queues off GET_VRING_BASE. > > > > Yes, that's only a workaround. I guess it has been there for quite a > > while, maybe at the time qemu doesn't send RESET_OWNER message. > > RESET_OWNER was a bad idea since it basically closes > everything. > > > > There are ENABLE/DISABLE messages for that. > > > > That's something new, > > That's part of multiqueue support. If you ignore them, > nothing works properly. > > > though I have plan to use them instead, we still > > need to make sure our code work with old qemu, without ENABLE/DISABLE > > messages. > > OK but don't rely on this for new code. > > > And I will think more while enabling live migration: I should have > > more time to address issues like this at that time. > > > > > Generally guys, don't take whatever QEMU happens to do for > > > granted! Look at the protocol spec under doc/specs directory, > > > if you are making more assumptions you must document them! > > > > Indeed. And we will try to address them bit by bit in future. > > > > --yliu > > But don't pile up these workarounds meanwhile. I'm very worried. The > way you are carrying on, each new QEMU is likely to break your > assumptions. I think it may be saner to increase the minimum QEMU version supported in each DPDK release, dropping old stuff progressively. Michael, you are welcome to suggest how to move precisely. Thanks