From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: preparations for 4.4.1, 4.3.3, and 4.2.5 Date: Tue, 20 May 2014 09:31:46 -0400 Message-ID: <537B5942.4050302@oracle.com> References: <5379E20E02000078000136E7@mail.emea.novell.com> <537A2D640200007800013B4B@mail.emea.novell.com> <537A2D640200007800013B4B@mail.emea.novell.com> <537A661F.2080709@oracle.com> <537B6685020000780001414A@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" 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 1Wmk8G-0003uI-0o for xen-devel@lists.xenproject.org; Tue, 20 May 2014 13:31:04 +0000 In-Reply-To: <537B6685020000780001414A@mail.emea.novell.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: Jan Beulich Cc: xen-devel List-Id: xen-devel@lists.xenproject.org On 05/20/2014 08:28 AM, Jan Beulich wrote: >>>> On 19.05.14 at 22:14, wrote: >> Hypervisor: >> 88e64cb x86/HVM: use fixed TSC value when saving or restoring domain >> b95fd03 x86/svm: enable TSC scaling >> 82713ec x86: use native RDTSC(P) execution when guest and host >> frequencies are the same > My understanding was that these are solely about performance, > not correctness. That would make them weak candidates for > 4.4.1 (under the slightly relaxed rules we put on x.y.1 releases), > but not any of the older trees. Do you have a different view? No, these are correctness fixes. The main thing (in this context) about 82713ec is reverting part of 4aab59a3 which broke migration on SVM (in principle I think you can take only the first hunk from it) 88e64cb fixes the fact that TSCs get unsynchronized after migration. And it needs some of the interfaces introduced in b95fd03 (which in itself is indeed mostly about performance) -boris