From patchwork Wed Sep 21 13:06:45 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 672863 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3sfKf52FPNz9svs for ; Wed, 21 Sep 2016 23:07:09 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933592AbcIUNGu (ORCPT ); Wed, 21 Sep 2016 09:06:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35260 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932959AbcIUNGt (ORCPT ); Wed, 21 Sep 2016 09:06:49 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6E8AD6198D; Wed, 21 Sep 2016 13:06:48 +0000 (UTC) Received: from thh440s.redhat.com (ovpn-116-56.ams2.redhat.com [10.36.116.56]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8LD6j7c017896; Wed, 21 Sep 2016 09:06:46 -0400 From: Thomas Huth To: Paul Mackerras , kvm-ppc@vger.kernel.org Cc: kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Michael Ellerman , Alexander Graf , stable@vger.kernel.org Subject: [PATCH] KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register Date: Wed, 21 Sep 2016 15:06:45 +0200 Message-Id: <1474463205-5965-1-git-send-email-thuth@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 21 Sep 2016 13:06:48 +0000 (UTC) Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org The MMCR2 register is available twice, one time with number 785 (privileged access), and one time with number 769 (unprivileged, but it can be disabled completely). In former times, the Linux kernel was using the unprivileged register 769 only, but since commit 8dd75ccb571f3c92c ("powerpc: Use privileged SPR number for MMCR2"), it uses the privileged register 785 instead. The KVM-PR code then of course also switched to use the SPR 785, but this is causing older guest kernels to crash, since these kernels still access 769 instead. So to support older kernels with KVM-PR again, we have to support register 769 in KVM-PR, too. Fixes: 8dd75ccb571f3c92c48014b3dabd3d51a115ab41 Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Thomas Huth --- arch/powerpc/include/asm/reg.h | 1 + arch/powerpc/kvm/book3s_emulate.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index f69f40f..978dada 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -737,6 +737,7 @@ #define MMCR0_FCHV 0x00000001UL /* freeze conditions in hypervisor mode */ #define SPRN_MMCR1 798 #define SPRN_MMCR2 785 +#define SPRN_UMMCR2 769 #define SPRN_MMCRA 0x312 #define MMCRA_SDSYNC 0x80000000UL /* SDAR synced with SIAR */ #define MMCRA_SDAR_DCACHE_MISS 0x40000000UL diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c index 2afdb9c..729f8fa 100644 --- a/arch/powerpc/kvm/book3s_emulate.c +++ b/arch/powerpc/kvm/book3s_emulate.c @@ -498,6 +498,7 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val) case SPRN_MMCR0: case SPRN_MMCR1: case SPRN_MMCR2: + case SPRN_UMMCR2: #endif break; unprivileged: @@ -640,6 +641,7 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val case SPRN_MMCR0: case SPRN_MMCR1: case SPRN_MMCR2: + case SPRN_UMMCR2: case SPRN_TIR: #endif *spr_val = 0;