From patchwork Wed Apr 5 13:58:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 747308 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vynXg0ytpz9s8B for ; Thu, 6 Apr 2017 00:00:03 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3vynXg0B94zDqLD for ; Thu, 6 Apr 2017 00:00:03 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vynWM1mdszDqH6 for ; Wed, 5 Apr 2017 23:58:55 +1000 (AEST) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 40293B4C5D; Wed, 5 Apr 2017 13:58:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 40293B4C5D Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=thuth@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 40293B4C5D Received: from thh440s.str.redhat.com (dhcp-192-189.str.redhat.com [10.33.192.189]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6688D94E61; Wed, 5 Apr 2017 13:58:52 +0000 (UTC) From: Thomas Huth To: Paul Mackerras , kvm-ppc@vger.kernel.org Subject: [PATCH v3] KVM: PPC: Book3S PR: Do not fail emulation with mtspr/mfspr for unknown SPRs Date: Wed, 5 Apr 2017 15:58:51 +0200 Message-Id: <1491400731-2492-1-git-send-email-thuth@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 05 Apr 2017 13:58:53 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" According to the PowerISA 2.07, mtspr and mfspr should not always generate an illegal instruction exception when being used with an undefined SPR, but rather treat the instruction as a NOP or inject a privilege exception in some cases, too - depending on the SPR number. Also turn the printk here into a ratelimited print statement, so that the guest can not flood the dmesg log of the host by issueing lots of illegal mtspr/mfspr instruction here. Signed-off-by: Thomas Huth --- v3: - Make sure that we do not advance the program counter after we've already changed it due to injecting a program interrupt v2: - Inject illegal instruction program interrupt instead of emulation assist interrupt (according to the last programming note in section 6.5.9 of Book III of the PowerISA v2.07) arch/powerpc/kvm/book3s_emulate.c | 34 ++++++++++++++++++++++++++-------- arch/powerpc/kvm/emulate.c | 8 ++++++++ 2 files changed, 34 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c index 8359752..68d6898 100644 --- a/arch/powerpc/kvm/book3s_emulate.c +++ b/arch/powerpc/kvm/book3s_emulate.c @@ -503,10 +503,18 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val) break; unprivileged: default: - printk(KERN_INFO "KVM: invalid SPR write: %d\n", sprn); -#ifndef DEBUG_SPR - emulated = EMULATE_FAIL; -#endif + pr_info_ratelimited("KVM: invalid SPR write: %d\n", sprn); + if (sprn & 0x10) { + if (kvmppc_get_msr(vcpu) & MSR_PR) { + kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV); + emulated = EMULATE_AGAIN; + } + } else { + if ((kvmppc_get_msr(vcpu) & MSR_PR) || sprn == 0) { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + emulated = EMULATE_AGAIN; + } + } break; } @@ -648,10 +656,20 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val break; default: unprivileged: - printk(KERN_INFO "KVM: invalid SPR read: %d\n", sprn); -#ifndef DEBUG_SPR - emulated = EMULATE_FAIL; -#endif + pr_info_ratelimited("KVM: invalid SPR read: %d\n", sprn); + if (sprn & 0x10) { + if (kvmppc_get_msr(vcpu) & MSR_PR) { + kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV); + emulated = EMULATE_AGAIN; + } + } else { + if ((kvmppc_get_msr(vcpu) & MSR_PR) || sprn == 0 || + sprn == 4 || sprn == 5 || sprn == 6) { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + emulated = EMULATE_AGAIN; + } + } + break; } diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index b379146..c873ffe 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -259,10 +259,18 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) case OP_31_XOP_MFSPR: emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt); + if (emulated == EMULATE_AGAIN) { + emulated = EMULATE_DONE; + advance = 0; + } break; case OP_31_XOP_MTSPR: emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs); + if (emulated == EMULATE_AGAIN) { + emulated = EMULATE_DONE; + advance = 0; + } break; case OP_31_XOP_TLBSYNC: