From patchwork Tue Sep 27 01:47:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12989663 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18D8CC07E9D for ; Tue, 27 Sep 2022 01:49:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229462AbiI0Bte (ORCPT ); Mon, 26 Sep 2022 21:49:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230003AbiI0Btd (ORCPT ); Mon, 26 Sep 2022 21:49:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FC9A2BCF; Mon, 26 Sep 2022 18:49:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B56D06151E; Tue, 27 Sep 2022 01:49:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02B8EC433D7; Tue, 27 Sep 2022 01:49:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664243370; bh=MBf/QZvYrr/+1ypzuJfgis+Aql70e5TU6XjS8eDZRZs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QTpItj9AR1UXnDzWSj3NFSlcvxnqfbs//QHLqAcuSKc2WIQSBXJS6uue/f2IxSyOw 5dxM8kWmVVuGCwM/zpdJ68kIs7JF3h4Wb95xiDB/Qec9jkqnbRLTMbkNxxSgfpHZ5+ ON0Y6Ys6bTOJN7Xo1TfdQKDkQ2qWc5ibBgtFv9LSb7siGi2L1VojufAHB3YrGoOaL0 pH2cGuYxuRmGVUkawKz1/BIAgRWJxm0KjmbThgxbNWCEZ4H2IpQqVYMFelRs4B8C6n X0mrU2OgqqAa7DrHTtdMPDlXD22Ubb/m8ITGBb3WqvvCIMQAaEyyMCBEJS4tD0GdDb wRE3cImr8HZNw== From: Eric Biggers To: linux-block@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: kernel-team@android.com, Israel Rukshin Subject: [RFC PATCH v6 2/4] blk-crypto: show supported key types in sysfs Date: Mon, 26 Sep 2022 18:47:16 -0700 Message-Id: <20220927014718.125308-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220927014718.125308-1-ebiggers@kernel.org> References: <20220927014718.125308-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org From: Eric Biggers 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/standard_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 --- Documentation/ABI/stable/sysfs-block | 18 ++++++++++++++ block/blk-crypto-sysfs.c | 35 ++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+) diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block index cd14ecb3c9a5..ab0a36a342d5 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -166,6 +166,16 @@ Description: encryption, refer to Documentation/block/inline-encryption.rst. +What: /sys/block//queue/crypto/hw_wrapped_keys +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 @@ -204,6 +214,14 @@ Description: use with inline encryption. +What: /sys/block//queue/crypto/standard_keys +Contact: linux-block@vger.kernel.org +Description: + [RO] The presence of this file indicates that the device + supports standard 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 fd93bd2f33b7..d1dbe50f806a 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 standard_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(standard_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 == &standard_keys_attr && + !(profile->key_types_supported & BLK_CRYPTO_KEY_TYPE_STANDARD)) + return 0; + + return 0444; +} static struct attribute *blk_crypto_attrs[] = { + &hw_wrapped_keys_attr.attr, &max_dun_bits_attr.attr, &num_keyslots_attr.attr, + &standard_keys_attr.attr, NULL, }; static const struct attribute_group blk_crypto_attr_group = { .attrs = blk_crypto_attrs, + .is_visible = blk_crypto_is_visible, }; /*