Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754243Ab2F1OAO (ORCPT ); Thu, 28 Jun 2012 10:00:14 -0400 Received: from nat28.tlf.novell.com ([130.57.49.28]:36126 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221Ab2F1OAN convert rfc822-to-8bit (ORCPT ); Thu, 28 Jun 2012 10:00:13 -0400 Message-Id: <4FEC7FB8020000780008C885@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.0 Date: Thu, 28 Jun 2012 15:00:56 +0100 From: "Jan Beulich" To: "Jinsong Liu" , "Will Auld" Cc: "Ashok Raj" , "Donald D Dugger" , "Haitao Shan" , "Jun Nakajima" , "Susie Li" , "Tony Luck" , "Xiantao Zhang" , "Yunhong Jiang" , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "Keir Fraser" Subject: RE: [xen vMCE RFC V0.2] xen vMCE design References: <4FEB236C020000780008C392@nat28.tlf.novell.com> <4FEC3B4A020000780008C673@nat28.tlf.novell.com> <4FEC463E020000780008C6A7@nat28.tlf.novell.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2021 Lines: 51 >>> On 28.06.12 at 15:38, "Liu, Jinsong" wrote: > Jan Beulich wrote: >>>>> On 28.06.12 at 11:40, "Liu, Jinsong" wrote: >>> So I would like to push new vMCE as quickly as possible. What's the >>> timeline of vMCE developing that xen 4.2 could accept? >> >> Weeks ago, really. See >> http://lists.xen.org/archives/html/xen-devel/2012-06/msg01619.html >> and follow-ups - we'd really only consider getting the save/restore >> interface into forward compatible shape as acceptable. >> >>> I wonder if we could make major >>> components of vMCE done before xen 4.2 timeline, and leave the >>> surrounding features and the corner cases done later? >> >> Unfortunately it's likely going to be even less. However, if split >> that way, chances are things could go into e.g. 4.2.1. >> >> Jan > > So let's look at current vMCE status first: > 1). functionally it work abnormally for guest (but tolerated by some guest > like linux/solaris); > 2). before xen 4.1 it blocks migration when migrate from big bank to small > bank platform; Before 4.2 you mean (in 4.1 we only have this as a backport in SLE11). > We may try some middle steps, minimal adjusting for xen 4.2 release (to > avoid futher compatible issue at xen 4.2.1, 4.3, ...): > 1). we don't handle vMCE function bugs, only make sure migration works OK; That's the minimal goal. > 2). update vMCE interface to a middle clean status: > * remove MCG_CTL (otherwise we have to add this useless MSR at new > vMCE); > * stick all 1's to MCi_CTL (avoid semantic difference); > * for MCG_CAP, clear MCG_CTL_P, limit to 2 banks (otherwise dirty code > have to be added at new vMCE); Whether that's acceptable would need to be seen when code is ready. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/