From patchwork Mon Feb 1 05:10:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Satya Tangirala X-Patchwork-Id: 12058053 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=-26.3 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, 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 029B4C433DB for ; Mon, 1 Feb 2021 05:11:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCFFC64E0A for ; Mon, 1 Feb 2021 05:11:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229633AbhBAFLP (ORCPT ); Mon, 1 Feb 2021 00:11:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229613AbhBAFLM (ORCPT ); Mon, 1 Feb 2021 00:11:12 -0500 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E326C061786 for ; Sun, 31 Jan 2021 21:10:30 -0800 (PST) Received: by mail-qt1-x84a.google.com with SMTP id o7so9820729qtw.7 for ; Sun, 31 Jan 2021 21:10:30 -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=OYJeK0hVnx58UggyO2F28C91EjwnMSUOQRtxvIVo72M=; b=hhBMcbrNpjg+7F40lsDSYrGfjddDSjDzLPjNoj37hrryrdNJI3HjA17Ec9iLbnAXT2 NsTQ5vwhzCaClkLOdwTBzvR61b3KFX42FjZ65Aojdi9MhgvT0we1qz0PH78vA+zxFuTR W+RfF1bSkIg+HRpUwem3hDBagASF30L+8GiMtJStszxT1UTYU9Wa3luhii9ptuNeXsEY 54L0tlZA1hTQyBvW4Mws9poX3Q+BHgCEW2VufY8TgVLS/2iQngS1gYDAS1aT6e8BejDp UFfrClUcXHtmchVdffrO+GNNlbRVMVKZDPs+sZYUSclSWT7ompouF/NTGnmr1d5zKALx 0DGw== 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=OYJeK0hVnx58UggyO2F28C91EjwnMSUOQRtxvIVo72M=; b=sw+G17aWptICm5aFrcMdcBx9LxMsJYrp69DuNktw/iW8TYithiRt5MmoDD8oXV76xS IAnX3Two6ToFE+CZzh19sjSTN6GmVU6e3JBrx2aDQ5t0ha5h2Fzg0dnBFKFR8iGzdtMl BJ+XGdQ7Z+XT7q5VSXOefmtaBxGsel34Y2A9BfjZvwsZryL6Vsb2eTjbCQrwVmuci3oz Gp1WFk8P7Q5f4dbrkyJ9J1f00h2ZSmuIsz5EewgOWavBUWnedfTjXfKHatH3079lMsqQ Kah8FygNH4O3s5J0u3ZSXx9FHBuuDqjEfLv8RFO3tEaXyjMfW3wqa44gmL860PkOTJSZ O5kQ== X-Gm-Message-State: AOAM532X5SzcN0AgVoRrP8YSoxVkrn9hweMnLMgscLnLDTpieWenlQL5 vCDd62CTjPZ9G3rTpoR4Ckof3Kxn49SyF+KtvYAq3604oJuQxpRBuLF8pt92gDDlvGGUMSVLoBa V7/jAkoB4UP6et7rxUTkP3Ma6i82odBfdHxxjnheNVyzce3RjX0ihCUkVGN+SqKR+cUnZ X-Google-Smtp-Source: ABdhPJzA4ai7ItUQd6ZhrYgFG/L5lCvckpTLSTAjIG3efXljDLlJWi4+i8Dybs8vpLbTmOxvCmAX9oNJGns= 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:a05:6214:48f:: with SMTP id ay15mr13728404qvb.58.1612156229581; Sun, 31 Jan 2021 21:10:29 -0800 (PST) Date: Mon, 1 Feb 2021 05:10:15 +0000 In-Reply-To: <20210201051019.1174983-1-satyat@google.com> Message-Id: <20210201051019.1174983-2-satyat@google.com> Mime-Version: 1.0 References: <20210201051019.1174983-1-satyat@google.com> X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH v4 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 Precedence: bulk List-ID: X-Mailing-List: linux-block@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 --- 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 */