Re: [PATCH v1 11/11] scsi: ufs: ufs-qcom: support ICE keyslot partitioning for guest VMs

[Linlin Zhang <linlin.zhang@oss.qualcomm.com>]

On 8/31/2026 3:03 PM, Krzysztof Kozlowski wrote:
> On 27/08/2026 18:07, Linlin Zhang wrote:
>> From: linlzhan <linlin.zhang@oss.qualcomm.com>
>>
>> On Qualcomm platforms where UFS inline encryption is shared between
>> the host and guest VMs, the ICE hardware keyslots must be partitioned
>> so that each VM operates only within its own physical slot range.
>> Without this, the host's blk_crypto_profile would manage all hardware
>> slots, conflicting with slots already allocated to guests.
>>
>> Add ufs_qcom_ice_parse_slot_table() to read the qcom,ice-keyslot-map
>> device-tree node.  The function parses all child entries and validates
>> that no entry's slot range or the combined total exceeds the hardware
>> slot count from REG_UFS_CCAP.  The first child entry is taken as the
>> host's own reservation; its slot count and offset are returned to the
>> caller.
>>
>> In ufs_qcom_ice_init(), use the parsed host reservation to initialize
>> the blk_crypto_profile with only the host's slot count rather than the
>> full hardware range.  Set profile->slot_offset so that
>> blk_crypto_keyslot_index() returns the correct physical ICE slot
>> number when programming hardware.  If no qcom,ice-keyslot-map node is
>> present, the existing behaviour (profile manages all slots) is
>> preserved.
>>
>> Note: This patch is submitted for visibility. The ufs-qcom driver
>> gets its max_slots and slot_offset based on the the current
>> DT-based keyslot mechanis. we are aware this may need to be replaced
>> by a TZ SCM interface, submit it RFC for design discussion.
>>
>> Signed-off-by: linlzhan <linlin.zhang@oss.qualcomm.com>
>> ---
>>  drivers/ufs/host/ufs-qcom.c | 91 ++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 90 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
>> index 62396212a0a7..0611ab50f4cc 100644
>> --- a/drivers/ufs/host/ufs-qcom.c
>> +++ b/drivers/ufs/host/ufs-qcom.c
>> @@ -163,6 +163,74 @@ static inline void ufs_qcom_ice_enable(struct ufs_qcom_host *host)
>>  		qcom_ice_enable(host->ice);
>>  }
>>  
>> +/**
>> + * ufs_qcom_ice_parse_slot_table() - parse qcom,ice-keyslot-map DT node
>> + * @dev:          UFS controller device
>> + * @hw_max_slots: total physical ICE keyslots reported by REG_UFS_CCAP
>> + * @num_slots:    receives host max_ice_slots (0 = no partitioning)
>> + * @slot_offset:  receives host ice-slot-offset
>> + *
>> + * Parses the qcom,ice-keyslot-map device-tree node.  The first child entry
>> + * is the host's own reservation; subsequent children are guest reservations.
>> + * Validates that no entry's range exceeds @hw_max_slots and that the sum of
>> + * all entries does not exceed @hw_max_slots.
>> + *
>> + * If no qcom,ice-keyslot-map phandle is present, sets @num_slots to 0 and
>> + * returns 0.  Returns -EINVAL if any entry or the total exceeds @hw_max_slots.
>> + */
>> +static int ufs_qcom_ice_parse_slot_table(struct device *dev,
>> +					 unsigned int hw_max_slots,
>> +					 unsigned int *num_slots,
>> +					 unsigned int *slot_offset)
>> +{
>> +	struct device_node *slots_np, *child;
>> +	unsigned int total_slots = 0;
>> +	bool first = true;
>> +	int ret = 0;
>> +
>> +	*num_slots   = 0;
>> +	*slot_offset = 0;
>> +
>> +	slots_np = of_parse_phandle(dev->of_node, "qcom,ice-keyslot-map", 0);
> 
> No
> 
>> +	if (!slots_np)
>> +		return 0;
>> +
>> +	for_each_child_of_node(slots_np, child) {
>> +		u32 off, max;
>> +
>> +		if (of_property_read_u32(child, "qcom,ice-slot-offset", &off) ||
>> +		    of_property_read_u32(child, "qcom,max-ice-slots", &max))
> 
> No, there is no such ABI.
> 

ACK

This is submitted for visibility. It may be revised in a future version to use
a TZ SCM query interface if current out-of-band key operation in the guest is
approved.

> 
> Best regards,
> Krzysztof