From: Eric Biggers Date: Tue, 4 Feb 2025 06:00:36 +0000 (-0800) Subject: blk-crypto: show supported key types in sysfs X-Git-Tag: v6.15-rc1~166^2~69 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e35fde43e25ad725d27315992fba8088d1210b01;p=thirdparty%2Flinux.git blk-crypto: show supported key types in sysfs Add sysfs files that indicate which type(s) of keys are supported by the inline encryption hardware associated with a particular request queue: /sys/block/$disk/queue/crypto/hw_wrapped_keys /sys/block/$disk/queue/crypto/raw_keys Userspace can use the presence or absence of these files to decide what encyption settings to use. Don't use a single key_type file, as devices might support both key types at the same time. Signed-off-by: Eric Biggers Tested-by: Bartosz Golaszewski # sm8650 Link: https://lore.kernel.org/r/20250204060041.409950-3-ebiggers@kernel.org Signed-off-by: Jens Axboe --- diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index 0cceb2badc836..890cde28bf90d 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -229,6 +229,17 @@ Description: encryption, refer to Documentation/block/inline-encryption.rst. +What: /sys/block//queue/crypto/hw_wrapped_keys +Date: February 2025 +Contact: linux-block@vger.kernel.org +Description: + [RO] The presence of this file indicates that the device + supports hardware-wrapped inline encryption keys, i.e. key blobs + that can only be unwrapped and used by dedicated hardware. For + more information about hardware-wrapped inline encryption keys, + see Documentation/block/inline-encryption.rst. + + What: /sys/block//queue/crypto/max_dun_bits Date: February 2022 Contact: linux-block@vger.kernel.org @@ -267,6 +278,15 @@ Description: use with inline encryption. +What: /sys/block//queue/crypto/raw_keys +Date: February 2025 +Contact: linux-block@vger.kernel.org +Description: + [RO] The presence of this file indicates that the device + supports raw inline encryption keys, i.e. keys that are managed + in raw, plaintext form in software. + + What: /sys/block//queue/dax Date: June 2016 Contact: linux-block@vger.kernel.org diff --git a/block/blk-crypto-sysfs.c b/block/blk-crypto-sysfs.c index a304434489bac..e832f403f2002 100644 --- a/block/blk-crypto-sysfs.c +++ b/block/blk-crypto-sysfs.c @@ -31,6 +31,13 @@ static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr) return container_of(attr, struct blk_crypto_attr, attr); } +static ssize_t hw_wrapped_keys_show(struct blk_crypto_profile *profile, + struct blk_crypto_attr *attr, char *page) +{ + /* Always show supported, since the file doesn't exist otherwise. */ + return sysfs_emit(page, "supported\n"); +} + static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile, struct blk_crypto_attr *attr, char *page) { @@ -43,20 +50,48 @@ static ssize_t num_keyslots_show(struct blk_crypto_profile *profile, return sysfs_emit(page, "%u\n", profile->num_slots); } +static ssize_t raw_keys_show(struct blk_crypto_profile *profile, + struct blk_crypto_attr *attr, char *page) +{ + /* Always show supported, since the file doesn't exist otherwise. */ + return sysfs_emit(page, "supported\n"); +} + #define BLK_CRYPTO_RO_ATTR(_name) \ static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name) +BLK_CRYPTO_RO_ATTR(hw_wrapped_keys); BLK_CRYPTO_RO_ATTR(max_dun_bits); BLK_CRYPTO_RO_ATTR(num_keyslots); +BLK_CRYPTO_RO_ATTR(raw_keys); + +static umode_t blk_crypto_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj); + struct blk_crypto_attr *a = attr_to_crypto_attr(attr); + + if (a == &hw_wrapped_keys_attr && + !(profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_HW_WRAPPED)) + return 0; + if (a == &raw_keys_attr && + !(profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_RAW)) + return 0; + + return 0444; +} static struct attribute *blk_crypto_attrs[] = { + &hw_wrapped_keys_attr.attr, &max_dun_bits_attr.attr, &num_keyslots_attr.attr, + &raw_keys_attr.attr, NULL, }; static const struct attribute_group blk_crypto_attr_group = { .attrs = blk_crypto_attrs, + .is_visible = blk_crypto_is_visible, }; /*