From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junjie Wei Subject: Re: VM save/restore Date: Mon, 20 Aug 2012 16:54:22 -0400 Message-ID: <5032A3FE.30402@oracle.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Keir Fraser Cc: Jan Beulich , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 08/18/2012 03:34 AM, Keir Fraser wrote: > On 18/08/2012 07:38, "Keir Fraser" wrote: > >> >>> I think if a VM can be successfully started, then save/restore should >>> also work. So I made a patch and did some testing. >> >> The check for 64 VCPUs is to cover the fact we only save/restore a 64-bit >> vcpumap. That would need fixing too surely, ot CPUs > 64 would be offline >> after restore I would imagine. > > How about the attached patch? It might actually work properly, unlike yours. > ;) > >>> The above problem is gone but there are new ones. >>> >>> Let me summarize the result here. >>> >>> With the patch, save/restore works fine as long as it can be started, >>> except two cases. >>> >>> 1) 32-bit guests can be configured with VCPUs > 32 and started, >>> but the guest can only make use of 32 of them. > > HVM guest? I don't know why this is. You will have to investigate some more > what has happened to the rest of your VCPUs! I think it should definitely > work. Cc Jan in case he has any thoughts. > >>> 2) 32-bit PVM guests can be configured with VCPUs > 64 and started, >>> but `xm save' does not work. > > That's because your changes to the save/restore code were wrong. Try my > patch instead. > > -- Keir > Tested. Your patch works perfectly for all cases. :) Thanks, Junjie