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

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

Dear Paolo

This is a ping for the following.
If you don't mind, could you give me some feedback?
Thank you very much.

Jeuk


On 23. 9. 21. 17:38, Jeuk Kim wrote:
> Dear Paolo
>
> Hi. I've been looking into how ufs-lu can share code with scsi-hd.
>
> I have verified that ufs-lu can use scsi-hd's code, and I would like 
> to modify it to do so.
>
> I've validated two possible fixes.
> I'd like to hear your thoughts.
>
> Option1.
> As you mentioned, using ufsbus, which inherits from scsibus, removes 
> the ufs-lu device type and use scsi-hd. (like -device ufs,id=ufs0 
> -device scsi-hd,bus=ufs0)
> I've verified that this method is implementable, except for one problem.
> Because we are using the scsi-hd type instead of the ufs-lu type, the 
> ufs has to manage all the ufs-lu specific data (such as the unit 
> descriptor).
> However, since there is no ufs_lu_realize() function, we need a way to 
> notify the ufs when a new scsi-hd device is added.
> Would there be a way to let the ufs know that a new scsi-hd has been 
> added at scsi_hd_realize() time?
>
> Option 2.
> Use qdev_new() & qdev_realize() to make ufs-lu have a virtual scsi bus 
> and scsi-hd.
> The ufs-lu can pass through SCSI commands to the virtual scsi-hd.
> This is similar to the method used by the device "usb-storage".
>
> With this method, I can keep the ufs-lu device type (ufs_lu_realize() 
> makes it convenient to manage ufs-lu related data) and avoid 
> duplicating code with scsi-hd.
> So I prefer this approach, but the annotation for "usb-storage" is 
> marked with a "Hack alert", so I'm not sure if this is the right way.
> The code can be found in usb_msd_storage_realize() 
> (hw/usb/dev-storage-classic.c:51).
>
> I am wondering if you could give me some advice on this and your 
> preferred direction for fixing it.
>
> Thank you so much.
>
> Jeuk
>