From patchwork Thu Oct 15 21:46:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Satya Tangirala X-Patchwork-Id: 11841223 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=-9.7 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 8A062C43457 for ; Fri, 16 Oct 2020 10:19:19 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CDF3E2084C for ; Fri, 16 Oct 2020 10:19:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CDF3E2084C Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-294-InKvxaWRN9eCbAtn0_t3Yg-1; Fri, 16 Oct 2020 06:19:15 -0400 X-MC-Unique: InKvxaWRN9eCbAtn0_t3Yg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7EAAB107AFB7; Fri, 16 Oct 2020 10:19:10 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D2B2A76663; Fri, 16 Oct 2020 10:19:08 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 6F26A44A60; Fri, 16 Oct 2020 10:19:05 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 09FLkmFZ001488 for ; Thu, 15 Oct 2020 17:46:48 -0400 Received: by smtp.corp.redhat.com (Postfix) id 194E913BBA4; Thu, 15 Oct 2020 21:46:48 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast04.extmail.prod.ext.rdu2.redhat.com [10.11.55.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1367316754E for ; Thu, 15 Oct 2020 21:46:46 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id EBF7D102F1E0 for ; Thu, 15 Oct 2020 21:46:45 +0000 (UTC) Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-399-UF8Q1Vf5M4eKNZr-5vU7BA-1; Thu, 15 Oct 2020 17:46:41 -0400 X-MC-Unique: UF8Q1Vf5M4eKNZr-5vU7BA-1 Received: by mail-pg1-f201.google.com with SMTP id b17so165798pgd.16 for ; Thu, 15 Oct 2020 14:46:41 -0700 (PDT) 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=ch6nvSub6LPLhqFDO+1Ngo8vwhJFQ7f44Mxixhhd0C0=; b=WXAeEFG4QYdfkYtPMxcspgp3FHw033GQYfdtWAOoGnhp3+5BPIMkIFfXm8o6J1lP4W P1akrHyNvhjzxcPN5ZlLrt76vccVI4+hR97yTkL+nO7M/nmcCSIAF3OYkIthMwAEQV8R X1iDT1xxoF8C8cdlizYjwuiSe1yNaFukH0yqf91HEZYpGnkGJkBF4eMjsMqB2gBvwjS8 IBQyP3SfGnSrm1cjLugHGb9lW0m9nZ+eqIxwGS9YgogTD/QzyzP7zHeXgSic0sN6+0h/ y19tFNaYC7N/DWZr7irjJHW7kOKjB+Z8pTTt9W/t8OWYPRdEDjbLd8+lx9Ancd6Mh4YN O/8A== X-Gm-Message-State: AOAM5304gHrzZmPdSHroG8yg7LxrunSjgXcRT3h8XvxvI0mZALZeYm/B zM/C97oVQdCCYBg54b7lmppJJ8AbWqI= X-Google-Smtp-Source: ABdhPJwhx2toIgFmDseGxQzGpK/2t4Kas5iEEhvkp2rHiVYQV9LBIlyMLStzdPkzAQOknVMMz1/GU/4rMHk= X-Received: from satyaprateek.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:1092]) (user=satyat job=sendgmr) by 2002:a17:90a:940c:: with SMTP id r12mr78628pjo.1.1602798400036; Thu, 15 Oct 2020 14:46:40 -0700 (PDT) Date: Thu, 15 Oct 2020 21:46:29 +0000 In-Reply-To: <20201015214632.41951-1-satyat@google.com> Message-Id: <20201015214632.41951-2-satyat@google.com> Mime-Version: 1.0 References: <20201015214632.41951-1-satyat@google.com> From: Satya Tangirala To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Mimecast-Bulk-Signature: yes X-Mimecast-Spam-Signature: bulk X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-loop: dm-devel@redhat.com X-Mailman-Approved-At: Fri, 16 Oct 2020 06:18:44 -0400 Cc: Jens Axboe , Satya Tangirala , Mike Snitzer , Alasdair Kergon , Eric Biggers Subject: [dm-devel] [PATCH v2 1/4] block: keyslot-manager: Introduce passthrough keyslot manager X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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 | 41 +++++++++++++++++++++++++++++++++ include/linux/keyslot-manager.h | 2 ++ 2 files changed, 43 insertions(+) diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c index 35abcb1ec051..5ad476dafeab 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. @@ -198,6 +203,10 @@ 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); @@ -318,6 +327,16 @@ 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) @@ -353,6 +372,9 @@ 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++) { @@ -394,3 +416,22 @@ 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. + * + * See blk_ksm_init() for more details about the parameters. + */ +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 */