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

[Fabiano Rosas]

Guenter Roeck <linux@roeck-us.net> writes:

> 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.

The issue still happens upstream and I have just written the exact same
fix for it, so I'm adding my:

Reviewed-by: Fabiano Rosas <farosas@suse.de>