From patchwork Mon Nov 6 14:15:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liran Alon X-Patchwork-Id: 10043547 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 74684602BF for ; Mon, 6 Nov 2017 14:15:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5B9EF29CB8 for ; Mon, 6 Nov 2017 14:15:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4F25129CC9; Mon, 6 Nov 2017 14:15:31 +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, UNPARSEABLE_RELAY 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 C603529CB8 for ; Mon, 6 Nov 2017 14:15:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753355AbdKFOP3 (ORCPT ); Mon, 6 Nov 2017 09:15:29 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:25791 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753283AbdKFOP2 (ORCPT ); Mon, 6 Nov 2017 09:15:28 -0500 Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id vA6EFNH1028181 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 6 Nov 2017 14:15:24 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id vA6EFNMx028993 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 6 Nov 2017 14:15:23 GMT Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id vA6EFM42004680; Mon, 6 Nov 2017 14:15:23 GMT Received: from liran-pc.ravello.local (/213.57.127.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 06 Nov 2017 06:15:22 -0800 From: Liran Alon To: pbonzini@redhat.com, rkrcmar@redhat.com, kvm@vger.kernel.org Cc: jmattson@google.com, idan.brown@oracle.com, Liran Alon , Konrad Rzeszutek Wilk Subject: [PATCH v2] KVM: nVMX/nSVM: Don't intercept #UD when running L2 Date: Mon, 6 Nov 2017 16:15:10 +0200 Message-Id: <1509977710-29704-1-git-send-email-liran.alon@oracle.com> X-Mailer: git-send-email 1.9.1 X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When running L2, #UD should be intercepted by L1 or just forwarded directly to L2. It should not reach L0 x86 emulator. Therefore, set intercept for #UD only based on L1 exception-bitmap. Also add WARN_ON_ONCE() on L0 #UD intercept handlers to make sure it is never reached while running L2. This improves commit ae1f57670703 ("KVM: nVMX: Do not emulate #UD while in guest mode") by removing an unnecessary exit from L2 to L0 on #UD when L1 doesn't intercept it. In addition, SVM L0 #UD intercept handler doesn't handle correctly the case it is raised from L2. In this case, it should forward the #UD to guest instead of x86 emulator. As done in VMX #UD intercept handler. This commit fixes this issue as-well. Signed-off-by: Liran Alon Reviewed-by: Nikita Leshenko Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Paolo Bonzini Reviewed-by: Wanpeng Li --- arch/x86/kvm/svm.c | 9 ++++++++- arch/x86/kvm/vmx.c | 9 ++++----- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 0e68f0b3cbf7..e49d44afbe9a 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -361,6 +361,7 @@ static void recalc_intercepts(struct vcpu_svm *svm) { struct vmcb_control_area *c, *h; struct nested_state *g; + u32 h_intercept_exceptions; mark_dirty(svm->vmcb, VMCB_INTERCEPTS); @@ -371,9 +372,14 @@ static void recalc_intercepts(struct vcpu_svm *svm) h = &svm->nested.hsave->control; g = &svm->nested; + /* No need to intercept #UD if L1 doesn't intercept it */ + h_intercept_exceptions = + h->intercept_exceptions & ~(1U << UD_VECTOR); + c->intercept_cr = h->intercept_cr | g->intercept_cr; c->intercept_dr = h->intercept_dr | g->intercept_dr; - c->intercept_exceptions = h->intercept_exceptions | g->intercept_exceptions; + c->intercept_exceptions = + h_intercept_exceptions | g->intercept_exceptions; c->intercept = h->intercept | g->intercept; } @@ -2188,6 +2194,7 @@ static int ud_interception(struct vcpu_svm *svm) { int er; + WARN_ON_ONCE(is_guest_mode(&svm->vcpu)); er = emulate_instruction(&svm->vcpu, EMULTYPE_TRAP_UD); if (er != EMULATE_DONE) kvm_queue_exception(&svm->vcpu, UD_VECTOR); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 95a01609d7ee..dfa856d31b17 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1878,7 +1878,7 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) { u32 eb; - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) | + eb = (1u << PF_VECTOR) | (1u << MC_VECTOR) | (1u << DB_VECTOR) | (1u << AC_VECTOR); if ((vcpu->guest_debug & (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) == @@ -1896,6 +1896,8 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) */ if (is_guest_mode(vcpu)) eb |= get_vmcs12(vcpu)->exception_bitmap; + else + eb |= 1u << UD_VECTOR; vmcs_write32(EXCEPTION_BITMAP, eb); } @@ -5881,10 +5883,7 @@ static int handle_exception(struct kvm_vcpu *vcpu) return 1; /* already handled by vmx_vcpu_run() */ if (is_invalid_opcode(intr_info)) { - if (is_guest_mode(vcpu)) { - kvm_queue_exception(vcpu, UD_VECTOR); - return 1; - } + WARN_ON_ONCE(is_guest_mode(vcpu)); er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD); if (er != EMULATE_DONE) kvm_queue_exception(vcpu, UD_VECTOR);