Page History

Kai

Access to (shared) physical ethernet

and guest-to-guest communication

Done initial browsing of the specification. Opinions still pending.

Use-cases: ?

Completeness: Protocol: , VIRTIO spec: (see comment)

Need in Embedded/Automotive: None? Can we find a use-case?

Applicability: For what it does, seems ok. But might not be really needed and therefore "not applicable". Is there something else/more needed?

WIP

Essentially used for "shared folder" capability between host & guest, as in desktop (or maybe some server) usage. Its applicability to embedded hypervisor usage, in which the "host" is not really being used by itself) seems questionable. What's the use-case?

In VIRTIO spec: A PCI type device can indicate that it is going to use the 9P protocol. The specification also has 9P as a specific separate device type. Other than that, I found no further description of such a device type. The protocol is specified elsewhere and complemented by scattered information regarding the specific implementations (Xen, KVM, QEMU, ...)

The protocol seems proven and supposedly OK for what it does. Possibly more security features needed, depending on use-case. VIRTIO however seems to defer the definition completely to "somewhere else"? At least a reference to a canonical specification would seem appropriate.

It is a minimalistic network file-system protocol. It seems apt for the task. Other network protocols like NFS, SMB/SAMBA etc. would be too heavy. It feels a bit esoteric, and while "reinventing" is bad, in this simple case would not be the worst ever, if VIRTIO had defined something else. Flexibility and security features seem somewhat glossed over. There's basically only "fixed user" or "pass-through" for mapping ownership on files in guest/host.

Links: Virtio 1.0 spec : {PCI-9P, 9P device type}.
Kernel support: Xen/Linux 4.12+ FE driver
Xen implementation details

A note on its documentation/definition not being very precise

A set of man pages seemingly defining P9? intro, others

QEMU instruction how to set up a VirtFS (P9).
Example/info how to natively mount a 9P network filesystem,
Source code for 9pfs FUSE driver

Example how to set up in Linux system

IOMMU coordinates of DMA devices'
connection to memory.

Automotive sensors:

Automotive sensors? Radar/LiDAR/? (or are they separate ECUs?)

Standard embedded sensor (ambient light...)

Some OS have requirements - eg. Android requires orientation sensor.

Example Assigning Host USB device to a Guest VM in KVM, here:

https://www.linux-kvm.org/page/USB_Host_Device_Assigned_to_Guest

Which use cases do we want to address?

•USB 2.0 (EHCI controller)
•USB 3.0 (xHCI controllers will replace ECHI)
•USB C
•Host only
•Device Classes:

• Mass storage. Enable use of USB device with volume provider
• Communications (e.g. serial, Ethernet)
• Human interface (e.g. keyboard, mouse)

•On-The-Go (system can function as both USB host and USB device)
•Hot-plug (partial support):

• Static configuration of device “tree”. A device can be plugged into a port. Dynamically detect device type.
• Device tree cannot grow dynamically, i.e. cannot plug in a hub

Other Serial devices?

(Where does LIN, etc. fit in?)

virtio-can: VIRTIO-based CAN driver

Sang-bum

+OpenSynergy with BT experience