From patchwork Fri May 22 17:22:10 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= X-Patchwork-Id: 6466921 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2D538C0020 for ; Fri, 22 May 2015 17:22:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5F2C6202EC for ; Fri, 22 May 2015 17:22:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76028202E5 for ; Fri, 22 May 2015 17:22:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757018AbbEVRWR (ORCPT ); Fri, 22 May 2015 13:22:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44347 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756792AbbEVRWQ (ORCPT ); Fri, 22 May 2015 13:22:16 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t4MHMGno022051 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 22 May 2015 13:22:16 -0400 Received: from potion (dhcp-27-168.brq.redhat.com [10.34.27.168]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id t4MHMD2j007370; Fri, 22 May 2015 13:22:14 -0400 Received: by potion (sSMTP sendmail emulation); Fri, 22 May 2015 19:22:13 +0200 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, Paolo Bonzini Subject: [PATCH] KVM: x86: preserve x2APIC LDR on INIT Date: Fri, 22 May 2015 19:22:10 +0200 Message-Id: <1432315330-20872-1-git-send-email-rkrcmar@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00,HK_RANDOM_FROM, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Logical x2APIC stops working if we rewrite it with zeros. The best references are SDM April 2015: 10.12.10.1 Logical Destination Mode in x2APIC Mode [...], the LDR are initialized by hardware based on the value of x2APIC ID upon x2APIC state transitions. and SDM April 2015: 10.12.10.2 Deriving Logical x2APIC ID from the Local x2APIC ID The LDR initialization occurs whenever the x2APIC mode is enabled Signed-off-by: Radim Kr?má? --- arch/x86/kvm/lapic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index c2a7d8a7a414..c789e00dfa8b 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1594,7 +1594,8 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) apic_set_reg(apic, APIC_DFR, 0xffffffffU); apic_set_spiv(apic, 0xff); apic_set_reg(apic, APIC_TASKPRI, 0); - kvm_apic_set_ldr(apic, 0); + if (!apic_x2apic_mode(apic)) + kvm_apic_set_ldr(apic, 0); apic_set_reg(apic, APIC_ESR, 0); apic_set_reg(apic, APIC_ICR, 0); apic_set_reg(apic, APIC_ICR2, 0);