Re: [PATCH v6 1/3] ublk: add opcode offsets for DRV_IN/DRV_OUT

From: Christoph Hellwig
Date: Tue Jul 11 2023 - 05:29:44 EST


On Tue, Jul 11, 2023 at 11:02:15AM +0200, Andreas Hindborg (Samsung) wrote:
>
> Christoph Hellwig <hch@xxxxxxxxxxxxx> writes:
>
> > On Tue, Jul 11, 2023 at 08:23:40AM +0200, Andreas Hindborg (Samsung) wrote:
> >> Yet most on-the-wire protocols for actual hardware does support this
> >> some way or another.
> >
> > Supports what? Passthrough? No.
>
> Both SCSI and NVMe has command identifier ranges reserved for vendor
> specific commands. I would assume that one use of these is to implement
> passthrough channels to a device for testing out new interfaces. Just
> guessing though.

Vendor specific commands is an entirely different concept from Linux
passthrough requests.