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

[Jeuk Kim]

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