Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757428Ab0F3WzR (ORCPT ); Wed, 30 Jun 2010 18:55:17 -0400 Received: from sj-iport-3.cisco.com ([171.71.176.72]:57371 "EHLO sj-iport-3.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754179Ab0F3WzP (ORCPT ); Wed, 30 Jun 2010 18:55:15 -0400 Authentication-Results: sj-iport-3.cisco.com; dkim=neutral (message not signed) header.i=none X-IronPort-AV: E=Sophos;i="4.53,515,1272844800"; d="scan'208";a="228800825" Date: Wed, 30 Jun 2010 15:51:37 -0700 From: "Tom Lyon" To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, iommu@lists.linux-foundation.org, chrisw@sous-sol.org, mst@redhat.com, dwmw2@infradead.org, joerg.roedel@amd.com Cc: aafabbri@cisco.com, scofeldm@cisco.com Subject: [PATCH] 2.6.34: simple IOMMU API extension to check safe interrupt remapping Message-ID: <4c2bca79.ZO9rQQJbYvPk39gc%pugs@cisco.com> User-Agent: Heirloom mailx 12.2 01/07/07 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1872 Lines: 44 This patch allows IOMMU users to determine whether the hardware and software support safe, isolated interrupt remapping. Not all Intel IOMMUs have the hardware, and the software for AMD is not there yet. Signed-off-by: Tom Lyon --- MST has convinced me that any user level driver for PCI master devices can't be safe unless there is an IOMMU protecting the APIC MSI/MSI-X interrupt addresses from device writes. This interrupt remapping is not present in all Intel IOMMUs and the code for the interrupt mapping in the AMD IOMMUs is not implemented yet. Needed by not-yet-accepted VFIO driver. diff -uprN linux-2.6.34/drivers/pci/intel-iommu.c iommuapi-linux-2.6.34/drivers/pci/intel-iommu.c --- linux-2.6.34/drivers/pci/intel-iommu.c 2010-05-16 14:17:36.000000000 -0700 +++ iommuapi-linux-2.6.34/drivers/pci/intel-iommu.c 2010-06-30 15:47:10.000000000 -0700 @@ -3705,6 +3705,10 @@ static int intel_iommu_domain_has_cap(st if (cap == IOMMU_CAP_CACHE_COHERENCY) return dmar_domain->iommu_snooping; +#ifdef CONFIG_INTR_REMAP + if (cap == IOMMU_CAP_SAFE_INTR_REMAP) + return intr_remapping_enabled; +#endif return 0; } diff -uprN linux-2.6.34/include/linux/iommu.h iommuapi-linux-2.6.34/include/linux/iommu.h --- linux-2.6.34/include/linux/iommu.h 2010-05-16 14:17:36.000000000 -0700 +++ iommuapi-linux-2.6.34/include/linux/iommu.h 2010-06-30 15:47:34.000000000 -0700 @@ -30,6 +30,7 @@ struct iommu_domain { }; #define IOMMU_CAP_CACHE_COHERENCY 0x1 +#define IOMMU_CAP_SAFE_INTR_REMAP 0x2 /* isolates device intrs */ struct iommu_ops { int (*domain_init)(struct iommu_domain *domain); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/