From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935481AbcIVReZ (ORCPT ); Thu, 22 Sep 2016 13:34:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56275 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965764AbcIVReV (ORCPT ); Thu, 22 Sep 2016 13:34:21 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , "matt@codeblueprint.co.uk, Paolo Bonzini" , Matt Fleming , Paolo Bonzini Subject: [PATCH 4.4 005/118] Revert "KVM: x86: fix missed hardware breakpoints" Date: Thu, 22 Sep 2016 19:28:25 +0200 Message-Id: <20160922172938.912741303@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160922172938.643879685@linuxfoundation.org> References: <20160922172938.643879685@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini [the change is part of 70e4da7a8ff62f2775337b705f45c804bb450454, which is already in stable kernels 4.1.y to 4.4.y. this part of the fix however was later undone, so remove the line again] 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. This happened because [0] and [1] are the same patch. [0] and [1] come from two different merges, and the later merge is trivially resolved; when [2] is applied it reverts both of them. Instead, when using the [1][2][0] order, patches applies normally but "KVM: x86: fix missed hardware breakpoints" is present in the final tree. Reported-by: Matt Fleming Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 1 - 1 file changed, 1 deletion(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2735,7 +2735,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu } kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); - vcpu->arch.switch_db_regs |= KVM_DEBUGREG_RELOAD; } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)