From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758484AbcIMOvH (ORCPT ); Tue, 13 Sep 2016 10:51:07 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:37934 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbcIMOvE (ORCPT ); Tue, 13 Sep 2016 10:51:04 -0400 Date: Tue, 13 Sep 2016 15:51:00 +0100 From: Matt Fleming To: Greg KH , Paolo Bonzini Cc: linux-kernel@vger.kernel.org Subject: KVM patches applied in weird order in -stable Message-ID: <20160913145100.GK3872@codeblueprint.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Folks, While hunting down a performance issue involving KVM I was surprised to see "native_set_debugreg()" as the first entry in `perf top`. Digging deeper, it looks as though the following patches were applied in the wrong order in -stable. This is the order as they appear in Linus' tree, [0] commit 4e422bdd2f84 ("KVM: x86: fix missed hardware breakpoints") [1] commit 172b2386ed16 ("KVM: x86: fix missed hardware breakpoints") [2] commit 70e4da7a8ff6 ("KVM: x86: fix root cause for missed hardware breakpoints") but this is the order for linux-4.4.y [1] commit fc90441e728a ("KVM: x86: fix missed hardware breakpoints") [2] commit 25e8618619a5 ("KVM: x86: fix root cause for missed hardware breakpoints") [0] commit 0f6e5e26e68f ("KVM: x86: fix missed hardware breakpoints") The upshot is that KVM_DEBUGREG_RELOAD is always set when returning from kvm_arch_vcpu_load() in stable, but not in Linus' tree.