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From: Paolo Bonzini <pbonzini@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Andrew Cooper <andrew.cooper3@citrix.com>
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>
Subject: Re: [patch V2 04/25] x86/apic: Make apic_pending_intr_clear() more robust
Date: Fri, 5 Jul 2019 22:49:55 +0200	[thread overview]
Message-ID: <3e9c8e2b-db98-6796-5241-7405f8c57564@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1907052213360.3648@nanos.tec.linutronix.de>

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?

> The more interesting question is whether this is all relevant. If I
> understood the issue correctly then this is mitigated by proper interrupt
> remapping.

Yes, and for Linux we're good I think.  VFIO by default refuses to use
the IOMMU if interrupt remapping is absent or disabled, and KVM's own
(pre-VFIO) IOMMU support was removed a couple years ago.  I guess the
secure boot lockdown patches should outlaw VFIO's
allow_unsafe_interrupts option, but that's it.

> 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.

Paolo

  parent reply	other threads:[~2019-07-05 20:50 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-04 15:51 [patch V2 00/25] x86/apic: Support for IPI shorthands Thomas Gleixner
2019-07-04 15:51 ` [patch V2 01/25] x86/kgbd: Use NMI_VECTOR not APIC_DM_NMI Thomas Gleixner
2019-07-05 21:43   ` Thomas Gleixner
2019-07-04 15:51 ` [patch V2 02/25] x86/apic: Invoke perf_events_lapic_init() after enabling APIC Thomas Gleixner
2019-07-04 15:51 ` [patch V2 03/25] x86/apic: Soft disable APIC before initializing it Thomas Gleixner
2019-07-04 15:51 ` [patch V2 04/25] x86/apic: Make apic_pending_intr_clear() more robust Thomas Gleixner
2019-07-05 15:47   ` Andrew Cooper
2019-07-05 19:06     ` Andy Lutomirski
2019-07-05 20:17       ` Andrew Cooper
2019-07-05 20:36       ` Thomas Gleixner
2019-07-05 20:39         ` Andy Lutomirski
2019-07-07  8:27           ` Thomas Gleixner
2019-07-05 19:19     ` Nadav Amit
2019-07-05 20:47       ` Andrew Cooper
2019-07-05 20:25     ` Thomas Gleixner
2019-07-05 20:37       ` Andy Lutomirski
2019-07-05 20:49       ` Paolo Bonzini [this message]
2019-07-05 21:16         ` Andrew Cooper
2019-07-07  8:37         ` Thomas Gleixner
2019-07-09 14:43           ` Thomas Gleixner
2019-07-04 15:51 ` [patch V2 05/25] x86/apic: Move IPI inlines into ipi.c Thomas Gleixner
2019-07-04 15:51 ` [patch V2 06/25] x86/apic: Cleanup the include maze Thomas Gleixner
2019-07-04 15:51 ` [patch V2 07/25] x86/apic: Move ipi header into apic directory Thomas Gleixner
2019-07-04 15:51 ` [patch V2 08/25] x86/apic: Move apic_flat_64 " Thomas Gleixner
2019-07-04 15:51 ` [patch V2 09/25] x86/apic: Consolidate the apic local headers Thomas Gleixner
2019-07-04 15:51 ` [patch V2 10/25] x86/apic/uv: Make x2apic_extra_bits static Thomas Gleixner
2019-07-04 15:51 ` [patch V2 11/25] smp/hotplug: Track booted once CPUs in a cpumask Thomas Gleixner
2019-07-04 15:51 ` [patch V2 12/25] x86/cpu: Move arch_smt_update() to a neutral place Thomas Gleixner
2019-07-04 15:51 ` [patch V2 13/25] x86/hotplug: Silence APIC and NMI when CPU is dead Thomas Gleixner
2019-07-04 15:51 ` [patch V2 14/25] x86/apic: Remove dest argument from __default_send_IPI_shortcut() Thomas Gleixner
2019-07-04 15:52 ` [patch V2 15/25] x86/apic: Add NMI_VECTOR wait to IPI shorthand Thomas Gleixner
2019-07-04 15:52 ` [patch V2 16/25] x86/apic: Move no_ipi_broadcast() out of 32bit Thomas Gleixner
2019-07-04 15:52 ` [patch V2 17/25] x86/apic: Add static key to Control IPI shorthands Thomas Gleixner
2019-07-04 15:52 ` [patch V2 18/25] x86/apic: Provide and use helper for send_IPI_allbutself() Thomas Gleixner
2019-07-04 15:52 ` [patch V2 19/25] cpumask: Implement cpumask_or_equal() Thomas Gleixner
2019-07-04 15:52 ` [patch V2 20/25] x86/smp: Move smp_function_call implementations into IPI code Thomas Gleixner
2019-07-04 15:52 ` [patch V2 21/25] x86/smp: Enhance native_send_call_func_ipi() Thomas Gleixner
2019-07-05  1:26   ` Nadav Amit
2019-07-04 15:52 ` [patch V2 22/25] x86/apic: Remove the shorthand decision logic Thomas Gleixner
2019-07-04 15:52 ` [patch V2 23/25] x86/apic: Share common IPI helpers Thomas Gleixner
2019-07-04 15:52 ` [patch V2 24/25] x86/apic/flat64: Remove the IPI shorthand decision logic Thomas Gleixner
2019-07-04 15:52 ` [patch V2 25/25] x86/apic/x2apic: Implement IPI shorthands support Thomas Gleixner

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