Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933845Ab3E3Pen (ORCPT ); Thu, 30 May 2013 11:34:43 -0400 Received: from mail-vb0-f50.google.com ([209.85.212.50]:42615 "EHLO mail-vb0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932445Ab3E3Pef (ORCPT ); Thu, 30 May 2013 11:34:35 -0400 Message-ID: <51A7717D.6030203@redhat.com> Date: Thu, 30 May 2013 17:34:21 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 MIME-Version: 1.0 To: kvm@vger.kernel.org CC: linux-kernel@vger.kernel.org, gnatapov@redhat.com Subject: Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields References: <1369924555-30216-1-git-send-email-pbonzini@redhat.com> In-Reply-To: <1369924555-30216-1-git-send-email-pbonzini@redhat.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2302 Lines: 64 Il 30/05/2013 16:35, Paolo Bonzini ha scritto: > The x86-64 extended low-byte registers were fetched correctly from reg, > but not from mod/rm. > > This fixes another bug in the boot of RHEL5.9 64-bit, but it is still > not enough. Well, it is enough but it takes 2 minutes to reach the point where hardware virtualization is used. It is doing a lot of stuff in emulation mode because FS and GS have leftovers from the A20 test: FS =0000 0000000000000000 0000ffff 00009300 DPL=0 DS16 [-WA] GS =ffff 00000000000ffff0 0000ffff 00009300 DPL=0 DS16 [-WA] 0x00000000000113be: in $0x92,%al 0x00000000000113c0: or $0x2,%al 0x00000000000113c2: out %al,$0x92 0x00000000000113c4: xor %ax,%ax 0x00000000000113c6: mov %ax,%fs 0x00000000000113c8: dec %ax 0x00000000000113c9: mov %ax,%gs 0x00000000000113cb: inc %ax 0x00000000000113cc: mov %ax,%fs:0x200 0x00000000000113d0: cmp %gs:0x210,%ax 0x00000000000113d5: je 0x113cb The DPL < RPL test fails. Any ideas? Should we introduce a new intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)? Paolo > Cc: gnatapov@redhat.com > Cc: kvm@vger.kernel.org > Cc: # 3.9 > Signed-off-by: Paolo Bonzini > --- > arch/x86/kvm/emulate.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index aa68106..028b34f 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, > ctxt->modrm_seg = VCPU_SREG_DS; > > if (ctxt->modrm_mod == 3) { > + int highbyte_regs = ctxt->rex_prefix == 0; > + > op->type = OP_REG; > op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; > - op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, ctxt->d & ByteOp); > + op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, > + highbyte_regs && (ctxt->d & ByteOp)); > if (ctxt->d & Sse) { > op->type = OP_XMM; > op->bytes = 16; > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/