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: 9664159 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 80FAF602B8 for ; Wed, 5 Apr 2017 13:59:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7226928563 for ; Wed, 5 Apr 2017 13:59:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6663C28587; Wed, 5 Apr 2017 13:59:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 091DD28563 for ; Wed, 5 Apr 2017 13:59:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751097AbdDEN7U (ORCPT ); Wed, 5 Apr 2017 09:59:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46868 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752118AbdDEN6x (ORCPT ); Wed, 5 Apr 2017 09:58:53 -0400 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 Cc: kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.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) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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: