On Wed, Nov 13, 2024 at 12:24 PM Jason fab <siliconfab@xxxxxxxxx> wrote: > > On Wed, Nov 13, 2024 at 11:48 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Wed, Nov 13, 2024 at 11:27:47AM +0530, Jason fab wrote: > > > Hello, > > > > > > I would like to know if the linux kernel usb subsystem supports > > > Virtualization based Trusted IO Management (USB VTIO)? > > > > What exactly is that, I can't seem to search for it and have not heard > > of it before. Do you have a link to it somewhere? Is there a USB.org > > specification published for it? > > I came across the below xHCI document and am wondering if the > Linux kernel already supports it. > > Here is the link to the document: > https://www.intel.com/content/dam/www/public/us/en/documents/technical-specifications/extensible-host-controler-interface-usb-xhci.pdf > Section 4.5 USB Virtualization Based Trusted IO Management (USB VTIO): I would like to know if Linux Kernel supports the above USB VTIO feature. If yes, appreciate if someone can share steps/documents to enable it. -Thanks > > The USB Virtualization based Trusted IO Management capability provided > by the xHC is optional functionality that enables a multi SW/HW function > ownership and access model for the various XHCI defined memory structures > and messages. As an example we can view a PCI based xHC implementation > as using the PCI defined function as the method to comply with the USB VTIO > requirements. > > The PCI Bus/Device/Function (BDF) for a given PCI function is determined during > the standard PCI enumeration of devices. PCI controllers captures its BDF when > it receives a downstream Type-0 Config Write (CfgWr0) cycle targeting its > Configuration header. This latched value is used as a "Requester ID" or > “DMA Identification” for all transactions initiated by the controller. > The PCI BDF > which is determined by the standard PCI discovery/enumeration process will be > referred to as the Primary DMA-ID. > > > > thanks, > > > > greg k-h
