From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [PATCH 01/21] Revert "vhost: workaround MQ fails to startup" Date: Sun, 24 Sep 2017 12:41:59 +0200 Message-ID: References: <20170831095023.21037-1-maxime.coquelin@redhat.com> <20170831095023.21037-2-maxime.coquelin@redhat.com> <20170907115448.GA9736@yliu-home> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: dev@dpdk.org, jfreiman@redhat.com, tiwei.bie@intel.com, mst@redhat.com, vkaplans@redhat.com, jasowang@redhat.com To: Yuanhan Liu Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id BE60D2F7D for ; Sun, 24 Sep 2017 12:42:06 +0200 (CEST) In-Reply-To: Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 09/07/2017 02:59 PM, Maxime Coquelin wrote: > Hi Yuanhan, > > On 09/07/2017 01:54 PM, Yuanhan Liu wrote: >> On Thu, Aug 31, 2017 at 11:50:03AM +0200, Maxime Coquelin wrote: >>> This reverts commit 04d81227960b5c1cf2f11f492100979ead20c526. >>> >>> As agreed when this workaround was introduced, it can be reverted >>> as Qemu v2.10 that fixes the issue is now out. >> >> First of all, I'm very sorry for being so late on review! >> >> I didn't quite remember we have come an agreement on that. > > >> I think my >> old concern still counts: how do you handle the combo like DPDK v17.11 >> and QEMU v2.7-2.9 (assume we take this patch in DPDK v17.11) ? >> >> Note that it's not a trivial bug, it's a fatal bug that freezes QEMU, >> IIRC > IIRC, I also raised the concern initially but after having listed the > possible solutions, I thought we agreed there were no trivial way to > detect the bug in Qemu and so we would re-enable it once upstream Qemu > got fixed. > > Note that we're talking about upstream here, which should not be used in > production. Distro's Qemu v2.7/v2.9 should be fixed, as RHEL-7.4 has been. > > Any thougths? Actually, stable v2.9.1 contains the fix, so only v2.7 and v2.8 are impacted. This is a good news, however it prevents to detect vulnerable Qemu versions based on new features bit introduced in v2.10. Maxime > Maxime > >>     --yliu >> >>> The reply-ack feature is required for vhost-user IOMMU support. >>> >>> Signed-off-by: Maxime Coquelin