From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: support for more than 32 VCPUs when migrating PVHVM guest Date: Mon, 2 Feb 2015 10:58:00 +0000 Message-ID: <54CF5838.5020007@citrix.com> References: <87k300wpwj.fsf@vitty.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YIEhj-0001qd-Bu for xen-devel@lists.xenproject.org; Mon, 02 Feb 2015 10:58:07 +0000 In-Reply-To: <87k300wpwj.fsf@vitty.brq.redhat.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: Vitaly Kuznetsov , Konrad Rzeszutek Wilk Cc: xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On 02/02/15 10:47, Vitaly Kuznetsov wrote: > Hi Konrad, > > I just hit an issue with PVHVM guests after save/restore (or migration), > if a PVHVM guest has > 32 VCPUs it hangs. Turns out, you saw it almost a > year ago and even wrote patches to call VCPUOP_register_vcpu_info after > resume. Unfortunately these patches never made it to xen/kernel. Do you > have a plan to pick this up? What were the arguments against your > suggestion? 32 VCPUs is the legacy limit for HVM guests, but should not have any remaining artefacts these days. Do you know why the hang occurs? I can't spot anything in the legacy migration code which would enforce such a limit. What is the subject of the thread you reference so I can search for it? ~Andrew