From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 1/4] PCI / ACPI: Identify external PCI devices Date: Fri, 16 Nov 2018 01:18:04 -0800 Message-ID: <20181116091804.GA4548@infradead.org> References: <20181113112700.GT2500@lahna.fi.intel.com> <20181113114527.GA12821@e107981-ln.cambridge.arm.com> <20181115102239.GU2500@lahna.fi.intel.com> <20181115111356.GA599@e107981-ln.cambridge.arm.com> <20181115113737.GW2500@lahna.fi.intel.com> <20181115120736.pscly6zwd3k2tvd2@wunner.de> <20181115121627.GA2500@lahna.fi.intel.com> <20181115174608.GA17691@e107981-ln.cambridge.arm.com> <20181115191026.GE4179@lahna.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20181115191026.GE4179@lahna.fi.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Mika Westerberg Cc: Yehezkel Bernat , ashok.raj@intel.com, Mario Limonciello , michael.jamet@intel.com, Christian Kellner , rjw@rjwysocki.net, Anthony Wong , LKML , Andreas Noever , iommu@lists.linux-foundation.org, lukas@wunner.de, jacob.jun.pan@intel.com, linux-pci@vger.kernel.org, Bjorn Helgaas , linux-acpi@vger.kernel.org, David Woodhouse List-Id: iommu@lists.linux-foundation.org On Thu, Nov 15, 2018 at 09:10:26PM +0200, Mika Westerberg wrote: > FireWire is kind of different but there are connectors such as > ExpressCard and NVMe (over U.2 connector) which carry PCIe and are > relatively easy to access without need for a screwdriver. AFAIK some > eGPUs are also using some other proprietary (non-TBT) connector that > carries PCIe. U.2 is a data center internal form factor with hot plug capability. If you enable an iommu for that by default you will make a lot of people very unhappy. More importantly NVMe is now used for the current/next generation Compact Flash and SD cards, which contain full PCIe gen 3 links.