Re: [PATCH v2 00/10] Hardware wrapped key support for qcom ice and ufs

[Eric Biggers <ebiggers@kernel.org>]

On Wed, Aug 30, 2023 at 11:00:07AM +0100, Srinivas Kandagatla wrote:
> 
> 3. We are adding these apis/callbacks in common code without doing any
> compatible or SoC checks. Is this going to be a issue if someone tries
> fscrypt?

ufs-qcom only declares support for wrapped keys if it's supported.  See patch 5
of this series:

+	if (qcom_ice_hwkm_supported(host->ice))
+		hba->quirks |= UFSHCD_QUIRK_USES_WRAPPED_CRYPTO_KEYS;

That in turn uses:

+bool qcom_ice_hwkm_supported(struct qcom_ice *ice)
+{
+	return (ice->hwkm_version > 0);
+}
+EXPORT_SYMBOL_GPL(qcom_ice_hwkm_supported);

Which in turn comes from the ICE version being >= 3.2.  It does seem a bit
suspicious; it probably should check for both the ICE version and the
availability of QCOM_SCM_ES_GENERATE_ICE_KEY, QCOM_SCM_ES_PREPARE_ICE_KEY, and
QCOM_SCM_ES_IMPORT_ICE_KEY.  Regardless, it sounds like you want it to be
determined by something set in the device tree instead?  I don't think it's been
demonstrated that that's necessary.  If we can detect the hardware capabilities
dynamically, we should do that, right?

- Eric