From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 11/13] KVM: VMX: Preserve segment limit and access rights in real mode Date: Tue, 21 Aug 2012 17:07:08 +0300 Message-ID: <1345558030-29370-12-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]:28137 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754339Ab2HUOIB (ORCPT ); Tue, 21 Aug 2012 10:08:01 -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 q7LE81VQ006083 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 21 Aug 2012 10:08:01 -0400 In-Reply-To: <1345558030-29370-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: While this is undocumented, real processors do not reload the segment limit and access rights when loading a segment register in real mode. Real programs rely on it so we need to comply with this behaviour. Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d4b1b16..c16b375 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3114,6 +3114,9 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu, if (seg == VCPU_SREG_TR || var->selector == vmx_read_guest_seg_selector(vmx, seg)) return; + var->base = vmx_read_guest_seg_base(vmx, seg); + var->selector = vmx_read_guest_seg_selector(vmx, seg); + return; } var->base = vmx_read_guest_seg_base(vmx, seg); var->limit = vmx_read_guest_seg_limit(vmx, seg); -- 1.7.11.3