From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH] iommu/amd: Assign default IOMMU when there is only one IOMMU Date: Mon, 14 Dec 2015 16:08:05 +0100 Message-ID: <20151214150805.GE11292@8bytes.org> References: <1449874478-31770-1-git-send-email-Suravee.Suthikulpanit@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1449874478-31770-1-git-send-email-Suravee.Suthikulpanit@amd.com> Sender: linux-kernel-owner@vger.kernel.org To: Suravee Suthikulpanit Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org List-Id: iommu@lists.linux-foundation.org On Fri, Dec 11, 2015 at 04:54:38PM -0600, Suravee Suthikulpanit wrote: > Current driver makes assumption that device with devid zero is always > included in the range of devices to be managed by IOMMU. However, > certain FW does not include devid zero in IVRS table. > This has caused IOMMU perf driver to fail to initialize. Hmm, this is a firmware bug. Is this bug seen in any systems that are for sale? > This patch implements a workaround for this case by always assign > devid zero to be handled by the first IOMMU. Otherwise its better to fix the firmware than to add workarounds. Joerg