From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9680FECE564 for ; Wed, 19 Sep 2018 14:33:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56BBD2086E for ; Wed, 19 Sep 2018 14:33:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 56BBD2086E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732480AbeISUMJ (ORCPT ); Wed, 19 Sep 2018 16:12:09 -0400 Received: from mga06.intel.com ([134.134.136.31]:14360 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731179AbeISUMI (ORCPT ); Wed, 19 Sep 2018 16:12:08 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Sep 2018 07:33:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,394,1531810800"; d="scan'208";a="74286402" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.148]) by orsmga007.jf.intel.com with ESMTP; 19 Sep 2018 07:33:55 -0700 Message-ID: <1537367635.9937.4.camel@intel.com> Subject: Re: [PATCH RESEND] kvm/x86: propagate fetch fault into guest From: Sean Christopherson To: Peng Hao , pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, peng.hao2@zte.com, Peng Hao Date: Wed, 19 Sep 2018 07:33:55 -0700 In-Reply-To: <1537311828-4547-1-git-send-email-penghao122@sina.com.cn> References: <1537311828-4547-1-git-send-email-penghao122@sina.com.cn> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2-0ubuntu3.2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-09-18 at 19:03 -0400, Peng Hao wrote: > From: Peng Hao > > When handling ept misconfig exit, it will call emulate instruction > with insn_len = 0. The decode instruction function may return a fetch > fault and should propagate to guest. What fault is encountered, e.g. #PF, #UD, etc...?  Something like a #UD at this point should result in an exit to userspace as it means KVM was unable to emulate an instruction that was successfully decoded by hardware. > The problem will result to emulation fail. > KVM internal error. Suberror: 1 > emulation failure > EAX=f81a0024 EBX=f6a07000 ECX=f6a0737c EDX=f8be0118 > ESI=f6a0737c EDI=00000021 EBP=f6929f98 ESP=f6929f98 > EIP=f8bdd141 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 > ES =007b 00000000 ffffffff 00c0f300 DPL=3 DS   [-WA] > CS =0060 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA] > SS =0068 00000000 ffffffff 00c09300 DPL=0 DS   [-WA] > DS =007b 00000000 ffffffff 00c0f300 DPL=3 DS   [-WA] > FS =00d8 2c044000 ffffffff 00809300 DPL=0 DS16 [-WA] > GS =0033 081a44c8 01000fff 00d0f300 DPL=3 DS   [-WA] > LDT=0000 00000000 ffffffff 00000000 > TR =0080 f6ea0c80 0000206b 00008b00 DPL=0 TSS32-busy > GDT=     f6e99000 000000ff > IDT=     fffbb000 000007ff > CR0=80050033 CR2=b757d000 CR3=35d31000 CR4=001406d0 > > Signed-off-by: Peng Hao > Reviewed-by: Jiang Biao > --- >  arch/x86/kvm/emulate.c | 5 ++++- >  arch/x86/kvm/x86.c     | 4 +++- >  2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index 106482d..aecf9a72 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -5105,8 +5105,11 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) >   memcpy(ctxt->fetch.data, insn, insn_len); >   else { >   rc = __do_insn_fetch_bytes(ctxt, 1); > - if (rc != X86EMUL_CONTINUE) > + if (rc != X86EMUL_CONTINUE) { > + if (rc == X86EMUL_PROPAGATE_FAULT) > + ctxt->have_exception = true; >   return rc; > + } >   } >   >   switch (mode) { > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 542f631..27072e1 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6188,8 +6188,10 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, >   if (reexecute_instruction(vcpu, cr2, write_fault_to_spt, >   emulation_type)) >   return EMULATE_DONE; > - if (ctxt->have_exception && inject_emulated_exception(vcpu)) > + if (ctxt->have_exception) { > + inject_emulated_exception(vcpu); >   return EMULATE_DONE; > + } >   if (emulation_type & EMULTYPE_SKIP) >   return EMULATE_FAIL; >   return handle_emulation_failure(vcpu, emulation_type);