From patchwork Fri Sep 28 09:45:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 976120 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.b="Kds6wf0S"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42M6Jp1Hnvz9ssD for ; Fri, 28 Sep 2018 19:46:50 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729417AbeI1QJg (ORCPT ); Fri, 28 Sep 2018 12:09:36 -0400 Received: from ozlabs.org ([203.11.71.1]:43995 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729251AbeI1QJf (ORCPT ); Fri, 28 Sep 2018 12:09:35 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 42M6JX5PGQz9sD2; Fri, 28 Sep 2018 19:46:36 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1538127996; bh=Ri/6MOUHswXNmdYTJnUiqUwUhDi9TV0CMEVaDIGoeSg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kds6wf0Sr4aFSUwkhAOV3rPj2aTt4dU6HX1s/K0Nze9sKV56crAHFqJAXLEnlQOHZ d3uFqLuAuof0M21p5JEGc0ART+V/GmXztOhX1MhfdOV3DCCD2LZClvbBzO9HAnQJyG VuPoOb9iIIAw1HS/pAI6DbAOa0BMWtQP9nJY/Ly5SElV+o9nXaf0vPTxfmYeut+MAt yfx2JOEzwXQZhA8vEp5/7vu+e6x+lHQVbAbQ2ac2vL3zOTAo5wW6sVTYd7DWBlVdco XPQsBGHztkxjn/+Pv6dPlrcuD5hkGET5umuCz/aMtL2ORgE5f+mhqI8pKgQU6PY+8l WUGae6ahx+wYQ== From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Cc: linuxppc-dev@ozlabs.org, David Gibson Subject: [PATCH v2 29/33] KVM: PPC: Book3S HV: Sanitise hv_regs on nested guest entry Date: Fri, 28 Sep 2018 19:45:59 +1000 Message-Id: <1538127963-15645-30-git-send-email-paulus@ozlabs.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1538127963-15645-1-git-send-email-paulus@ozlabs.org> References: <1538127963-15645-1-git-send-email-paulus@ozlabs.org> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: Suraj Jitindar Singh restore_hv_regs() is used to copy the hv_regs L1 wants to set to run the nested (L2) guest into the vcpu structure. We need to sanitise these values to ensure we don't let the L1 guest hypervisor do things we don't want it to. We don't let data address watchpoints or completed instruction address breakpoints be set to match in hypervisor state. We also don't let L1 enable features in the hypervisor facility status and control register (HFSCR) for L2 which we have disabled for L1. That is L2 will get the subset of features which the L0 hypervisor has enabled for L1 and the features L1 wants to enable for L2. This could mean we give L1 a hypervisor facility unavailable interrupt for a facility it thinks it has enabled, however it shouldn't have enabled a facility it itself doesn't have for the L2 guest. We sanitise the registers when copying in the L2 hv_regs. We don't need to sanitise when copying back the L1 hv_regs since these shouldn't be able to contain invalid values as they're just what was copied out. Signed-off-by: Suraj Jitindar Singh Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/reg.h | 1 + arch/powerpc/kvm/book3s_hv_nested.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 9c42abf..47489f6 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -415,6 +415,7 @@ #define HFSCR_DSCR __MASK(FSCR_DSCR_LG) #define HFSCR_VECVSX __MASK(FSCR_VECVSX_LG) #define HFSCR_FP __MASK(FSCR_FP_LG) +#define HFSCR_INTR_CAUSE (ASM_CONST(0xFF) << 56) /* interrupt cause */ #define SPRN_TAR 0x32f /* Target Address Register */ #define SPRN_LPCR 0x13E /* LPAR Control Register */ #define LPCR_VPM0 ASM_CONST(0x8000000000000000) diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c index 2abe0cf..c3fb171 100644 --- a/arch/powerpc/kvm/book3s_hv_nested.c +++ b/arch/powerpc/kvm/book3s_hv_nested.c @@ -86,6 +86,22 @@ static void save_hv_return_state(struct kvm_vcpu *vcpu, int trap, } } +static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) +{ + /* + * Don't let L1 enable features for L2 which we've disabled for L1, + * but preserve the interrupt cause field. + */ + hr->hfscr &= (HFSCR_INTR_CAUSE | vcpu->arch.hfscr); + + /* Don't let data address watchpoint match in hypervisor state */ + hr->dawrx0 &= ~DAWRX_HYP; + + /* Don't let completed instruction address breakpt match in HV state */ + if ((hr->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER) + hr->ciabr &= ~CIABR_PRIV; +} + static void restore_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) { struct kvmppc_vcore *vc = vcpu->arch.vcore; @@ -198,6 +214,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD | LPCR_LPES | LPCR_MER; lpcr = (vc->lpcr & ~mask) | (l2_hv.lpcr & mask); + sanitise_hv_regs(vcpu, &l2_hv); restore_hv_regs(vcpu, &l2_hv); vcpu->arch.ret = RESUME_GUEST;