From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A893C433E6 for ; Thu, 11 Feb 2021 22:54:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 204F464E4B for ; Thu, 11 Feb 2021 22:54:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230019AbhBKWyh (ORCPT ); Thu, 11 Feb 2021 17:54:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229501AbhBKWyb (ORCPT ); Thu, 11 Feb 2021 17:54:31 -0500 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71A9FC061756 for ; Thu, 11 Feb 2021 14:53:51 -0800 (PST) Received: by mail-qk1-x749.google.com with SMTP id c63so5778158qkd.1 for ; Thu, 11 Feb 2021 14:53:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=7AM0u1xvi8rWerhtus0gkgsr+ctRsqYSopY+7YCNCuU=; b=YHXMLWoRrs5Tga9v4ug8VhkgXuFjpIarwAkKXOSGVN9CpUwPnymZN47mdVImCVFMzS EFxeY/39D+pMo2q0iXB5AodSVZNHFA2+OVhVxnEmm0bD71USTcZ6rq5j8ZrLK68t88Om tqtRnH5mgB+O8IF/uXdak4RfijjKXjfShaCyTj9hg830vJDVRDB4mAnbG9RVLAypglLz MZ1Q5dDZff3hsRiERW+8pETHyiqbi7yxHOWhPTy/aPdKTfu3Aea3iLm6JCd6UXaJRDBf LJxqb27hVA9csvmQ7nWtvLM2nGxTLPtzjI3AvT0l+Kxrb9pehbLghCxR73b1kz1rslEa Zf9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=7AM0u1xvi8rWerhtus0gkgsr+ctRsqYSopY+7YCNCuU=; b=ca0b6oBHn01w3Y4WNr+UfxgfY/PXgRuHkEELX1xNeswJUfe1S2vYL7OjWzmz9c7zqc 4Ra34D782Fc0jHJkdqwMCgWaUu65+6AJmznE2N+cILpekKTl2bpwX7iE8u2fK9N/2yLZ GZM1k881idBvV5fmWEen8kutZGRtaDqOkLLmkgyH5Khogu+/5skDwt4qvMVWpIYH6xeR uMiv0Fn/Yz7TGsL4L/7Ibi4cwxoEc+E3B+rmLwC+2zh+u2pKdESCESoe/qNfryV1w/f7 wgVSsS+Nv6q649Qjpex6neM8tOYXuKdGGyllku2f/KmUCvGAw/7zn2TyX9zKnDU/k3Nb +PMA== X-Gm-Message-State: AOAM532Mnw4P1IRMAmanhd/D2wQtCDrUZkKOo8fbs2U/A/ZE3WMHjxNh 8V6C13f/sD4EVRL5a5teHMHYz6y+j9o= X-Google-Smtp-Source: ABdhPJwtQFk7Sp4imxBMUoJh2UPtarEaoN31R7oWcM+JFisbkGFAI60SrSiHOXgLIFdEnZappBCaiKruEHM= Sender: "satyat via sendgmr" X-Received: from satyaprateek.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:1092]) (user=satyat job=sendgmr) by 2002:a0c:fd47:: with SMTP id j7mr73482qvs.22.1613084030680; Thu, 11 Feb 2021 14:53:50 -0800 (PST) Date: Thu, 11 Feb 2021 22:53:39 +0000 In-Reply-To: <20210211225343.3145732-1-satyat@google.com> Message-Id: <20210211225343.3145732-2-satyat@google.com> Mime-Version: 1.0 References: <20210211225343.3145732-1-satyat@google.com> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog Subject: [PATCH v5 1/5] block: keyslot-manager: Introduce passthrough keyslot manager From: Satya Tangirala To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Cc: Jens Axboe , Alasdair Kergon , Mike Snitzer , Eric Biggers , Satya Tangirala Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The device mapper may map over devices that have inline encryption capabilities, and to make use of those capabilities, the DM device must itself advertise those inline encryption capabilities. One way to do this would be to have the DM device set up a keyslot manager with a "sufficiently large" number of keyslots, but that would use a lot of memory. Also, the DM device itself has no "keyslots", and it doesn't make much sense to talk about "programming a key into a DM device's keyslot manager", so all that extra memory used to represent those keyslots is just wasted. All a DM device really needs to be able to do is advertise the crypto capabilities of the underlying devices in a coherent manner and expose a way to evict keys from the underlying devices. There are also devices with inline encryption hardware that do not have a limited number of keyslots. One can send a raw encryption key along with a bio to these devices (as opposed to typical inline encryption hardware that require users to first program a raw encryption key into a keyslot, and send the index of that keyslot along with the bio). These devices also only need the same things from the keyslot manager that DM devices need - a way to advertise crypto capabilities and potentially a way to expose a function to evict keys from hardware. So we introduce a "passthrough" keyslot manager that provides a way to represent a keyslot manager that doesn't have just a limited number of keyslots, and for which do not require keys to be programmed into keyslots. DM devices can set up a passthrough keyslot manager in their request queues, and advertise appropriate crypto capabilities based on those of the underlying devices. Blk-crypto does not attempt to program keys into any keyslots in the passthrough keyslot manager. Instead, if/when the bio is resubmitted to the underlying device, blk-crypto will try to program the key into the underlying device's keyslot manager. Signed-off-by: Satya Tangirala Reviewed-by: Eric Biggers Acked-by: Jens Axboe --- block/keyslot-manager.c | 39 +++++++++++++++++++++++++++++++++ include/linux/keyslot-manager.h | 2 ++ 2 files changed, 41 insertions(+) diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c index 86f8195d8039..ac7ce83a76e8 100644 --- a/block/keyslot-manager.c +++ b/block/keyslot-manager.c @@ -62,6 +62,11 @@ static inline void blk_ksm_hw_exit(struct blk_keyslot_manager *ksm) pm_runtime_put_sync(ksm->dev); } +static inline bool blk_ksm_is_passthrough(struct blk_keyslot_manager *ksm) +{ + return ksm->num_slots == 0; +} + /** * blk_ksm_init() - Initialize a keyslot manager * @ksm: The keyslot_manager to initialize. @@ -205,6 +210,10 @@ blk_status_t blk_ksm_get_slot_for_key(struct blk_keyslot_manager *ksm, int err; *slot_ptr = NULL; + + if (blk_ksm_is_passthrough(ksm)) + return BLK_STS_OK; + down_read(&ksm->lock); slot = blk_ksm_find_and_grab_keyslot(ksm, key); up_read(&ksm->lock); @@ -325,6 +334,16 @@ int blk_ksm_evict_key(struct blk_keyslot_manager *ksm, struct blk_ksm_keyslot *slot; int err = 0; + if (blk_ksm_is_passthrough(ksm)) { + if (ksm->ksm_ll_ops.keyslot_evict) { + blk_ksm_hw_enter(ksm); + err = ksm->ksm_ll_ops.keyslot_evict(ksm, key, -1); + blk_ksm_hw_exit(ksm); + return err; + } + return 0; + } + blk_ksm_hw_enter(ksm); slot = blk_ksm_find_keyslot(ksm, key); if (!slot) @@ -360,6 +379,9 @@ void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm) { unsigned int slot; + if (blk_ksm_is_passthrough(ksm)) + return; + /* This is for device initialization, so don't resume the device */ down_write(&ksm->lock); for (slot = 0; slot < ksm->num_slots; slot++) { @@ -401,3 +423,20 @@ void blk_ksm_unregister(struct request_queue *q) { q->ksm = NULL; } + +/** + * blk_ksm_init_passthrough() - Init a passthrough keyslot manager + * @ksm: The keyslot manager to init + * + * Initialize a passthrough keyslot manager. + * Called by e.g. storage drivers to set up a keyslot manager in their + * request_queue, when the storage driver wants to manage its keys by itself. + * This is useful for inline encryption hardware that doesn't have the concept + * of keyslots, and for layered devices. + */ +void blk_ksm_init_passthrough(struct blk_keyslot_manager *ksm) +{ + memset(ksm, 0, sizeof(*ksm)); + init_rwsem(&ksm->lock); +} +EXPORT_SYMBOL_GPL(blk_ksm_init_passthrough); diff --git a/include/linux/keyslot-manager.h b/include/linux/keyslot-manager.h index 18f3f5346843..323e15dd6fa7 100644 --- a/include/linux/keyslot-manager.h +++ b/include/linux/keyslot-manager.h @@ -103,4 +103,6 @@ void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm); void blk_ksm_destroy(struct blk_keyslot_manager *ksm); +void blk_ksm_init_passthrough(struct blk_keyslot_manager *ksm); + #endif /* __LINUX_KEYSLOT_MANAGER_H */ -- 2.30.0.478.g8a0d178c01-goog