Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756745Ab3JHQsN (ORCPT ); Tue, 8 Oct 2013 12:48:13 -0400 Received: from mail-ie0-f172.google.com ([209.85.223.172]:63166 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755385Ab3JHQsK (ORCPT ); Tue, 8 Oct 2013 12:48:10 -0400 MIME-Version: 1.0 In-Reply-To: <6A3DF150A5B70D4F9B66A25E3F7C888D0718FA58@039-SN2MPN1-011.039d.mgd.msft.net> References: <1379575763-2091-1-git-send-email-Bharat.Bhushan@freescale.com> <1379575763-2091-2-git-send-email-Bharat.Bhushan@freescale.com> <20130924235812.GD9302@google.com> <6A3DF150A5B70D4F9B66A25E3F7C888D0718FA58@039-SN2MPN1-011.039d.mgd.msft.net> From: Bjorn Helgaas Date: Tue, 8 Oct 2013 10:47:49 -0600 Message-ID: Subject: Re: [PATCH 1/7] powerpc: Add interface to get msi region information To: Bhushan Bharat-R65777 Cc: "alex.williamson@redhat.com" , "joro@8bytes.org" , "benh@kernel.crashing.org" , "galak@kernel.crashing.org" , "linux-kernel@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-pci@vger.kernel.org" , "agraf@suse.de" , Wood Scott-B07421 , "iommu@lists.linux-foundation.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1148 Lines: 23 On Thu, Oct 3, 2013 at 11:19 PM, Bhushan Bharat-R65777 wrote: >> I don't know enough about VFIO to understand why these new interfaces are >> needed. Is this the first VFIO IOMMU driver? I see vfio_iommu_spapr_tce.c and >> vfio_iommu_type1.c but I don't know if they're comparable to the Freescale PAMU. >> Do other VFIO IOMMU implementations support MSI? If so, do they handle the >> problem of mapping the MSI regions in a different way? > > PAMU is an aperture type of IOMMU while other are paging type, So they are completely different from what PAMU is and handle that differently. This is not an explanation or a justification for adding new interfaces. I still have no idea what an "aperture type IOMMU" is, other than that it is "different." But I see that Alex is working on this issue with you in a different thread, so I'm sure you guys will sort it out. Bjorn -- 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/