From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sean Christopherson <sean.j.christopherson@intel.com>
Subject: Re: [PATCH RESEND] kvm/x86: propagate fetch fault into guest
Date: Thu, 20 Sep 2018 10:42:45 -0700
Message-ID: <20180920174245.GA10381@linux.intel.com>
References: <1537311828-4547-1-git-send-email-penghao122@sina.com.cn>
 <1537367635.9937.4.camel@intel.com>
 <a3f05921-d802-efd6-65bb-7cb99f804f0f@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
Cc: Peng Hao <penghao122@sina.com.cn>, rkrcmar@redhat.com,
        tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org,
        peng.hao2@zte.com, Peng Hao <peng.hao2@zte.com.cn>
To: Paolo Bonzini <pbonzini@redhat.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <a3f05921-d802-efd6-65bb-7cb99f804f0f@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: kvm.vger.kernel.org

On Thu, Sep 20, 2018 at 06:32:10PM +0200, Paolo Bonzini wrote:
> On 19/09/2018 16:33, Sean Christopherson wrote:
> > On Tue, 2018-09-18 at 19:03 -0400, Peng Hao wrote:
> >> From: Peng Hao <peng.hao2@zte.com.cn>
> >>
> >> 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.
> 
> If it's the same bug as https://lore.kernel.org/patchwork/patch/850077/
> it would be a #PF.

Indeed it is, let's move this discussion to that thread.