On Wed, 2021-07-14 at 16:11 +0900, Chanho Park wrote:

UFS controller of ExynosAuto v9 SoC supports multi-host interface for
I/O

virtualization. In general, we're using para-virtualized driver to

support a block device by several virtual machines. However, it
should

be relayed by backend driver. Multi-host functionality extends the
host

controller by providing register interfaces that can be used by each

VM's ufs drivers respectively. By this, we can provide direct access
to

the UFS device for multiple VMs. It's similar with SR-IOV of PCIe.

Hi Chanho Park,
very inteseted in this patch. you mentined SR-IOV. In order to make
your patch work on the UFS, does UFS device side need changes?

or the common current 3.1 UFS can work with this new controller?

 

We divide this M-HCI as PH(Physical Host) and VHs(Virtual Host). The
PH

supports all UFSHCI functions(all SAPs) same as conventional UFSHCI
but

the VH only supports data transfer function. Thus, except UTP_CMD_SAP
and

UTP_TMPSAP, the PH should handle all the physical features.



This patch provides an initial implementation of PH part. M-HCI can

support up to four interfaces but this patch initially supports only
1

PH and 1 VH. For this, we uses TASK_TAG[7:5] field so TASK_TAG[4:0]
for

32 doorbel will be supported. After the PH is initiated, this will
send

I don't understand here.  how many doorbell registers you have now?
and doesn VHs have a doorbell register also? and each doorbell register
still supprts 32 tags?

Kind regards
Beab