From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3B63C2BA83 for ; Fri, 7 Feb 2020 18:18:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D90A21775 for ; Fri, 7 Feb 2020 18:18:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727843AbgBGSSO (ORCPT ); Fri, 7 Feb 2020 13:18:14 -0500 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:40632 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727570AbgBGSQs (ORCPT ); Fri, 7 Feb 2020 13:16:48 -0500 Received: from smtp.bitdefender.com (smtp01.buh.bitdefender.com [10.17.80.75]) by mx01.bbu.dsd.mx.bitdefender.com (Postfix) with ESMTPS id 3D989305D341; Fri, 7 Feb 2020 20:16:40 +0200 (EET) Received: from host.bbu.bitdefender.biz (unknown [195.210.4.22]) by smtp.bitdefender.com (Postfix) with ESMTPSA id 1F9393052071; Fri, 7 Feb 2020 20:16:40 +0200 (EET) From: =?UTF-8?q?Adalbert=20Laz=C4=83r?= To: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, Paolo Bonzini , Sean Christopherson , =?UTF-8?q?Mircea=20C=C3=AErjaliu?= , =?UTF-8?q?Adalbert=20Laz=C4=83r?= Subject: [RFC PATCH v7 35/78] KVM: x86: disable gpa_available optimization for fetch and page-walk NPF/EPT violations Date: Fri, 7 Feb 2020 20:15:53 +0200 Message-Id: <20200207181636.1065-36-alazar@bitdefender.com> In-Reply-To: <20200207181636.1065-1-alazar@bitdefender.com> References: <20200207181636.1065-1-alazar@bitdefender.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Mircea Cîrjaliu This change is needed because the introspection tool can write-protect guest page tables, exec-protect heap/stack pages and let KVM emulate the instruction that caused these violations. Signed-off-by: Mircea Cîrjaliu Signed-off-by: Adalbert Lazăr --- arch/x86/kvm/mmu/mmu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 5f0ddc6b67de..d28b7425c4f1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5636,8 +5636,13 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code, int r, emulation_type = 0; bool direct = vcpu->arch.mmu->direct_map; - /* With shadow page tables, fault_address contains a GVA or nGPA. */ - if (vcpu->arch.mmu->direct_map) { + /* + * With shadow page tables, fault_address contains a GVA or nGPA. + * On a fetch fault, fault_address contains the instruction pointer. + */ + if (vcpu->arch.mmu->direct_map && + likely(!(error_code & PFERR_FETCH_MASK)) && + (error_code & PFERR_GUEST_FINAL_MASK)) { vcpu->arch.gpa_available = true; vcpu->arch.gpa_val = cr2; }