From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754658AbcHVMkv (ORCPT ); Mon, 22 Aug 2016 08:40:51 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:53123 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751294AbcHVMku (ORCPT ); Mon, 22 Aug 2016 08:40:50 -0400 Date: Mon, 22 Aug 2016 14:38:35 +0200 (CEST) From: Thomas Gleixner To: Wanpeng Li cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Wanpeng Li , Joerg Roedel , Ingo Molnar , Peter Zijlstra Subject: Re: [PATCH] iommu/vt-d: Fix modify_irte NULL pointer In-Reply-To: <1471868589-3909-1-git-send-email-wanpeng.li@hotmail.com> Message-ID: References: <1471868589-3909-1-git-send-email-wanpeng.li@hotmail.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 22 Aug 2016, Wanpeng Li wrote: > From: Wanpeng Li > > native_smp_prepare_cpus > -> default_setup_apic_routing > -> enable_IR_x2apic > -> irq_remapping_prepare > -> intel_prepare_irq_remapping > -> parse_ioapics_under_ir => return 0 > -> ir_parse_ioapic_hpet_scope > -> ir_parse_one_ioapic_scope > -> intel_setup_irq_remapping > IR table is setup even if noapic boot parameter is added. > index ac59692..f1cb7c6 100644 > --- a/drivers/iommu/intel_irq_remapping.c > +++ b/drivers/iommu/intel_irq_remapping.c > @@ -854,6 +854,9 @@ static int ir_parse_one_ioapic_scope(struct acpi_dmar_device_scope *scope, > count = (scope->length - sizeof(struct acpi_dmar_device_scope)) > / sizeof(struct acpi_dmar_pci_path); > > + if (skip_ioapic_setup) > + return -ENODEV; Why are you adding this in the iommu code? We should not call any of the apic functions when apic is disabled. Thanks, tglx