Re: [PATCH 1/4] PCI / ACPI: Identify external PCI devices

[Christoph Hellwig]

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.