From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hongyang Yang Subject: Re: [RFC PATCH 3/3] remus: adjust x86 pv restore to support remus Date: Thu, 10 Jul 2014 11:30:05 +0800 Message-ID: <53BE08BD.3060308@cn.fujitsu.com> References: <1404892050-24650-1-git-send-email-yanghy@cn.fujitsu.com> <1404892050-24650-4-git-send-email-yanghy@cn.fujitsu.com> <53BD2477.1070505@citrix.com> <53BD26E0.9030406@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53BD26E0.9030406@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper , xen-devel@lists.xen.org Cc: rshriram@cs.ubc.ca, Ian.Jackson@eu.citrix.com, Ian.Campbell@citrix.com List-Id: xen-devel@lists.xenproject.org On 07/09/2014 07:26 PM, Andrew Cooper wrote: > On 09/07/14 12:16, Andrew Cooper wrote: >> On 09/07/14 08:47, Yang Hongyang wrote: >>> cache vcpu context when restore, and set context when stream >>> complete. >> Can you explain why this is needed? I can't see why it should be required. > > Actually, as part of reviewing this I have worked out why this is needed. > > It is a latent bug in the migration v2 series with all the x86 pv vcpu > state (not just the basic state), which is not triggered by a well > behaved sender. > > I shall fix it up in the base series. That's great, remember the bug I talked to you on IRC last time? This patch was targeted to avoid the bug, but I don't know why this bug happened, which I can tell is that if we don't cache the state, we will get mapping error when restore the CPU state next time, can you explain it in detail? Thanks in advance. > > ~Andrew > . > -- Thanks, Yang.