Re: [PULL 4/5] hw/ufs: Support for UFS logical unit

[Jeuk Kim <jeuk20.kim@gmail.com>]

On 2023-09-18 오후 1:41, Jeuk Kim wrote:
> On 2023-09-15 16:59, Paolo Bonzini wrote:
>> On 9/15/23 00:19, Jeuk Kim wrote:
>>> First, ufs-lu has a feature called "unit descriptor". This feature 
>>> shows the status of the ufs-lu
>>>
>>> and only works with UFS-specific "query request" commands, not SCSI 
>>> commands.
>>
>> This looks like something that can be implemented in the UFS subsystem.
>>
>>> UFS also has something called a well-known lu. Unlike typical SCSI 
>>> devices, where each lu is independent,
>>> UFS can control other lu's through the well-known lu.
>>
>> This can also be implemented in UfsBus.
>>
>>> Finally, UFS-LU will have features that SCSI-HD does not have, such 
>>> as the zone block command.
>>
>> These should be implemented in scsi-hd as well.
>>
>>> In addition to this, I wanted some scsi commands to behave 
>>> differently from scsi-hd, for example,
>>> the Inquiry command should read "QEMU UFS" instead of "QEMU HARDDISK",
>>> and the mode_sense_page command should have a different result.
>>
>> Some of these don't have much justification, and others (such as the 
>> control page) could be done in scsi-hd as well.
>>
>> We should look into cleaning this up and making ufs-lu share a lot 
>> more code with scsi-hd; possibly even supporting -device scsi-hd with 
>> UFS devices.  I am not going to ask you for a revert, but if this is 
>> not done before 8.2 is out, I will ask you to disable it by default 
>> in hw/ufs/Kconfig.
>>
>> In the future, please Cc the SCSI maintainers for UFS patches.
>>
>> Paolo
>>
>
> Thanks for the comment.
>
> ufs-lu took most of its code from scsi-hd, so I completely agree that 
> we should make scsi-hd code shareable to reduce code redundancy and 
> make it better.

Sorry about it. This sentence is misleading.

I meant to say "I completely agree that ufs-lu should be made to reuse 
scsi-hd code to reduce code redundancy and improve code quality."


>
> I will fix it and get back to you soon.
>
> Thank you.
>
>
> Sincerely,
>
> Jeuk
>

Thanks