From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 05/13] KVM: VMX: Allow real mode emulation using vm86 with dpl=0 Date: Tue, 21 Aug 2012 17:07:02 +0300 Message-ID: <1345558030-29370-6-git-send-email-avi@redhat.com> References: <1345558030-29370-1-git-send-email-avi@redhat.com> Cc: kvm@vger.kernel.org To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33103 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754339Ab2HUOHk (ORCPT ); Tue, 21 Aug 2012 10:07:40 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q7LE7eAn005991 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 21 Aug 2012 10:07:40 -0400 In-Reply-To: <1345558030-29370-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Real mode is always entered from protected mode with dpl=0. Since the dpl doesn't affect execution, and we already override it to 3 in the vmcs (as vmx requires), we can allow execution in that state. Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e94b90b..4f3d6ac 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3318,7 +3318,7 @@ static bool rmode_segment_valid(struct kvm_vcpu *vcpu, int seg) return false; if (var.limit != 0xffff) return false; - if (ar != 0xf3) + if ((ar | (3 << AR_DPL_SHIFT)) != 0xf3) return false; return true; -- 1.7.11.3