Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Received-SPF: None (esa6.hc3370-68.iphmx.com: no sender
  authenticity information available from domain of
  andrew.cooper3@citrix.com) identity=pra;
  client-ip=162.221.158.21; receiver=esa6.hc3370-68.iphmx.com;
  envelope-from="Andrew.Cooper3@citrix.com";
  x-sender="andrew.cooper3@citrix.com";
  x-conformance=sidf_compatible
Received-SPF: Pass (esa6.hc3370-68.iphmx.com: domain of
  Andrew.Cooper3@citrix.com designates 162.221.158.21 as
  permitted sender) identity=mailfrom;
  client-ip=162.221.158.21; receiver=esa6.hc3370-68.iphmx.com;
  envelope-from="Andrew.Cooper3@citrix.com";
  x-sender="Andrew.Cooper3@citrix.com";
  x-conformance=sidf_compatible; x-record-type="v=spf1";
  x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133
  ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4
  ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88
  ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ~all"
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  authenticity information available from domain of
  postmaster@mail.citrix.com) identity=helo;
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  envelope-from="Andrew.Cooper3@citrix.com";
  x-sender="postmaster@mail.citrix.com";
  x-conformance=sidf_compatible
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 p54=
Subject: Re: [patch V2 04/25] x86/apic: Make apic_pending_intr_clear() more
 robust
To:     Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>
CC:     LKML <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
        Nadav Amit <namit@vmware.com>,
        Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
        Stephane Eranian <eranian@google.com>,
        Feng Tang <feng.tang@intel.com>,
        "Andy Lutomirski" <luto@kernel.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        Andrew Cooper <Andrew.Cooper3@citrix.com>
References: <20190704155145.617706117@linutronix.de>
 <20190704155608.636478018@linutronix.de>
 <958a67c2-4dc0-52e6-43b2-1ebd25a59232@citrix.com>
 <alpine.DEB.2.21.1907052213360.3648@nanos.tec.linutronix.de>
 <3e9c8e2b-db98-6796-5241-7405f8c57564@redhat.com>
From:   Andrew Cooper <andrew.cooper3@citrix.com>
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Message-ID: <f4b39e63-9587-176c-697a-e91f0af357de@citrix.com>
Date:   Fri, 5 Jul 2019 22:16:50 +0100
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 05/07/2019 21:49, Paolo Bonzini wrote:
> On 05/07/19 22:25, Thomas Gleixner wrote:
>> In practice, this makes Linux vulnerable to CVE-2011-1898 / XSA-3, which
>> I'm disappointed to see wasn't shared with other software vendors at the
>> time.
> Oh, that brings back memories.  At the time I was working on Xen, so I
> remember that CVE.  IIRC there was some mitigation but the fix was
> basically to print a very scary error message if you used VT-d without
> interrupt remapping.  Maybe force the user to add something on the Xen
> command line too?

It was before my time.  I have no public comment on how the other
aspects of it were handled.

>> Is there any serious usage of virtualization w/o interrupt remapping left
>> or have the machines which are not capable been retired already?
> I think they were already starting to disappear in 2011, as I don't
> remember much worry about customers that were using systems without it.

ISTR Nehalem/Westmere era systems were the first to support interrupt
remapping, but were totally crippled with errata to the point of needing
to turn a prerequisite feature (Queued Invalidation) off.  I believe
later systems have it working to a first approximation.

As to the original question, whether people should be using such systems
is a different question to whether they actually are.

~Andrew