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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 726E7C433EF for ; Tue, 14 Sep 2021 15:50:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5470A61246 for ; Tue, 14 Sep 2021 15:50:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235270AbhINPv0 (ORCPT ); Tue, 14 Sep 2021 11:51:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:47108 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235136AbhINPvD (ORCPT ); Tue, 14 Sep 2021 11:51:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631634585; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=245jQK827gv9pORp/HoiEjyYDnHYg74f716xJlQFbt0=; b=GoKS9LVXx69mu2hxGBG7cW8KlKAmPr6wl4eE6hiDkz9PrGLrsDAn3qqnKE00IEMsQtv7xf C4FqNaDb4mQpud0IBUXUqX+n7aznc45UZI9h6CkiUsx0/mTmfHgi/5jROFdC7H0suxPLXA sawaIZNLPAyEGoeA3VfhK/beXWo6DiE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-277-4gGChjZqOIycN4nwhAkovg-1; Tue, 14 Sep 2021 11:49:44 -0400 X-MC-Unique: 4gGChjZqOIycN4nwhAkovg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE91F1084685; Tue, 14 Sep 2021 15:49:42 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id 44B445C261; Tue, 14 Sep 2021 15:49:28 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Vitaly Kuznetsov , Paolo Bonzini , Borislav Petkov , Bandan Das , linux-kernel@vger.kernel.org (open list), Joerg Roedel , Ingo Molnar , Wei Huang , Sean Christopherson , linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK), Maxim Levitsky , "H. Peter Anvin" , Jim Mattson , Thomas Gleixner , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Shuah Khan , Wanpeng Li Subject: [PATCH 07/14] KVM: x86: SVM: add warning for CVE-2021-3656 Date: Tue, 14 Sep 2021 18:48:18 +0300 Message-Id: <20210914154825.104886-8-mlevitsk@redhat.com> In-Reply-To: <20210914154825.104886-1-mlevitsk@redhat.com> References: <20210914154825.104886-1-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Just in case, add a warning ensuring that on guest entry, either both VMLOAD and VMSAVE intercept is enabled or vVMLOAD/VMSAVE is enabled. Signed-off-by: Maxim Levitsky --- arch/x86/kvm/svm/svm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 861ac9f74331..deeebd05f682 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3784,6 +3784,12 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu)); + /* Check that CVE-2021-3656 can't happen again */ + if (!svm_is_intercept(svm, INTERCEPT_VMSAVE) || + !svm_is_intercept(svm, INTERCEPT_VMSAVE)) + WARN_ON(!(svm->vmcb->control.virt_ext & + VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK)); + sync_lapic_to_cr8(vcpu); if (unlikely(svm->asid != svm->vmcb->control.asid)) { -- 2.26.3