VTIO support on USB

VTIO support on USB

[Jason fab]

Hello,

I would like to know if the linux kernel usb subsystem supports
Virtualization based Trusted IO Management (USB VTIO)?
If yes, could you please point me to any documentation and steps on
how to enable it?

-Thanks in advance

Re: VTIO support on USB

[Greg KH]

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?

thanks,

greg k-h

Re: VTIO support on USB

[Jason fab]

On Wed, Nov 13, 2024 at 11:48 AM Greg KH <gregkh@linuxfoundation.org> 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):

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

Re: VTIO support on USB

[Jason fab]

On Wed, Nov 13, 2024 at 12:24 PM Jason fab <siliconfab@gmail.com> wrote:
>
> On Wed, Nov 13, 2024 at 11:48 AM Greg KH <gregkh@linuxfoundation.org> 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