Re: [PATCH] scsi: megasas: Internal cdbs have 16-byte length

[Guenter Roeck]

On 2/17/24 01:06, Michael Tokarev wrote:
> > 28.02.2023 20:11, Guenter Roeck wrote:
> > > Host drivers do not necessarily set cdb_len in megasas io commands.
> > > With commits 6d1511cea0 ("scsi: Reject commands if the CDB length
> > > exceeds buf_len") and fe9d8927e2 ("scsi: Add buf_len parameter to
> > > scsi_req_new()"), this results in failures to boot Linux from affected
> > > SCSI drives because cdb_len is set to 0 by the host driver.
> > > Set the cdb length to its actual size to solve the problem.
>
> Has this been lost/forgotten?

Not sure. My understanding was that I could not prove that this is how
real hardware handles the situation, thus it wasn't applied. I carry it
locally in my builds of qemu, so it is not a problem for me. Note that
I didn't check if the problem has since been fixed differently. Maybe
that is the case and the problem no longer exists in the upstream version
of qemu.

Guenter