From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: [PATCH 2/7] KVM: VMX: relax check for CS register in rmode_segment_valid() Date: Wed, 12 Dec 2012 19:10:50 +0200 Message-ID: <1355332255-26612-3-git-send-email-gleb@redhat.com> References: <1355332255-26612-1-git-send-email-gleb@redhat.com> Cc: mtosatti@redhat.com To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:1556 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754314Ab2LLRLE (ORCPT ); Wed, 12 Dec 2012 12:11:04 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id qBCHB3f3028100 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 12 Dec 2012 12:11:04 -0500 In-Reply-To: <1355332255-26612-1-git-send-email-gleb@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: rmode_segment_valid() checks if segment descriptor can be used to enter vm86 mode. VMX spec mandates that in vm86 mode CS register will be of type data, not code. Lets allow guest entry with vm86 mode if the only problem with CS register is incorrect type. Otherwise entire real mode will be emulated. Signed-off-by: Gleb Natapov --- arch/x86/kvm/vmx.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4df3991..acbe86f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3383,6 +3383,8 @@ static bool rmode_segment_valid(struct kvm_vcpu *vcpu, int seg) var.dpl = 0x3; var.g = 0; var.db = 0; + if (seg == VCPU_SREG_CS) + var.type = 0x3; ar = vmx_segment_access_rights(&var); if (var.base != (var.selector << 4)) -- 1.7.10.4