Re: pcap DLT request for virtio-scsi SCSI transport

[Guy Harris <guy () alum mit edu>]

On Feb 28, 2012, at 3:05 AM, Stefan Hajnoczi wrote:

> The QEMU system emulator now supports the virtio-scsi SCSI transport
> for efficient virtualized SCSI I/O.  I would like to support
> virtio-scsi debugging and analysis with pcap.
>
> The pcap data will include the virtio buffers containing SCSI command
> metadata, CDB, and data-out buffer.  A similar structure is also used
> for SCSI responses with the data-in buffer and a footer.
>
> You can find detailed information on virtio-scsi in Appendix H of the
> virtio specification:
> http://ozlabs.org/~rusty/virtio-spec/virtio-0.9.4.pdf

OK, so what does a single packet look like?  Does each packet correspond to a single SCSI command or response?

> Is it possible to allocate a datalink type for virtio-scsi?
>
> Do you need a detailed specification of the virtio-scsi pcap mapping
> or should we publish the specification ourselves to enable others to
> easily read such files?

The entry on

        http://www.tcpdump.org/linktypes.html

for your link-layer header type should either

        1) have a link to one or more specifications that completely describe the data

or

        2) have a link to a page under http://www.tcpdump.org/linktypes that describes the part of the data that isn't 
described by such a specification.

If you want to publish the specification yourself, we can just link to it rather than creating our own 
http://www.tcpdump.org/linktypes page.-
This is the tcpdump-workers list.
Visit https://cod.sandelman.ca/ to unsubscribe.