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blk-crypto cleanups

PATCH Superseded Eric Biggers 2 participants 6 messages Sep 16, 2021

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v2 of 6 Superseded Latest is v6 →

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#0 lore raw

v2 cover blk-crypto cleanups

This series renames struct blk_keyslot_manager to struct blk_crypto_profile, as it is misnamed; it doesn't always manage keyslots. It's much more logical to think of it as the "blk-crypto profile" of a device, similar to blk_integrity_profile.

This series also improves the inline-encryption.rst documentation file, and cleans up blk-crypto-fallback a bit.

This series applies to v5.15-rc1.

Changed v1 => v2:
- Fixed a build error in blk-integrity.c.
- Removed a mention of "ksm" from a comment.
- Dropped the patch "blk-crypto-fallback: consolidate static variables".
- Added Acked-by and Reviewed-by tags.

Eric Biggers (4):
blk-crypto-fallback: properly prefix function and struct names
blk-crypto: rename keyslot-manager files to blk-crypto-profile
blk-crypto: rename blk_keyslot_manager to blk_crypto_profile
blk-crypto: update inline encryption documentation

 Documentation/block/inline-encryption.rst | 439 ++++++++--------
 block/Makefile                            |   2 +-
 block/blk-crypto-fallback.c               | 118 ++---
 block/blk-crypto-profile.c                | 564 +++++++++++++++++++++
 block/blk-crypto.c                        |  29 +-
 block/blk-integrity.c                     |   4 +-
 block/keyslot-manager.c                   | 578 ----------------------
 drivers/md/dm-core.h                      |   4 +-
 drivers/md/dm-table.c                     | 168 +++----
 drivers/md/dm.c                           |  10 +-
 drivers/mmc/core/crypto.c                 |  11 +-
 drivers/mmc/host/cqhci-crypto.c           |  33 +-
 drivers/scsi/ufs/ufshcd-crypto.c          |  32 +-
 drivers/scsi/ufs/ufshcd-crypto.h          |   9 +-
 drivers/scsi/ufs/ufshcd.c                 |   2 +-
 drivers/scsi/ufs/ufshcd.h                 |   6 +-
 include/linux/blk-crypto-profile.h        | 166 +++++++
 include/linux/blkdev.h                    |  18 +-
 include/linux/device-mapper.h             |   4 +-
 include/linux/keyslot-manager.h           | 120 -----
 include/linux/mmc/host.h                  |   4 +-
 21 files changed, 1194 insertions(+), 1127 deletions(-)
 create mode 100644 block/blk-crypto-profile.c
 delete mode 100644 block/keyslot-manager.c
 create mode 100644 include/linux/blk-crypto-profile.h
 delete mode 100644 include/linux/keyslot-manager.h

base-commit: 6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f

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#1 lore raw

PATCH v2 1/4 blk-crypto-fallback: properly prefix function and struct names

From: Eric Biggers <[email protected]>

For clarity, avoid using just the "blk_crypto_" prefix for functions and structs that are specific to blk-crypto-fallback. Instead, use "blk_crypto_fallback_". Some places already did this, but others didn't.

This is also a prerequisite for using "struct blk_crypto_keyslot" to mean a generic blk-crypto keyslot (which is what it sounds like). Rename the fallback one to "struct blk_crypto_fallback_keyslot".

---
 block/blk-crypto-fallback.c | 59 +++++++++++++++++++------------------
 1 file changed, 30 insertions(+), 29 deletions(-)
block/blk-crypto-fallback.c +30 -29
index c322176a1e099..82b302597b474 100644
@@ -72,7 +72,7 @@ static mempool_t *bio_fallback_crypt_ctx_pool;
 static DEFINE_MUTEX(tfms_init_lock);
 static bool tfms_inited[BLK_ENCRYPTION_MODE_MAX];
 
-static struct blk_crypto_keyslot {
+static struct blk_crypto_fallback_keyslot {
 	enum blk_crypto_mode_num crypto_mode;
 	struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
 } *blk_crypto_keyslots;
@@ -88,9 +88,9 @@ static struct bio_set crypto_bio_split;
  */
 static u8 blank_key[BLK_CRYPTO_MAX_KEY_SIZE];
 
-static void blk_crypto_evict_keyslot(unsigned int slot)
+static void blk_crypto_fallback_evict_keyslot(unsigned int slot)
 {
-	struct blk_crypto_keyslot *slotp = &blk_crypto_keyslots[slot];
+	struct blk_crypto_fallback_keyslot *slotp = &blk_crypto_keyslots[slot];
 	enum blk_crypto_mode_num crypto_mode = slotp->crypto_mode;
 	int err;
 
@@ -103,34 +103,34 @@ static void blk_crypto_evict_keyslot(unsigned int slot)
 	slotp->crypto_mode = BLK_ENCRYPTION_MODE_INVALID;
 }
 
-static int blk_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
-				      const struct blk_crypto_key *key,
-				      unsigned int slot)
+static int blk_crypto_fallback_keyslot_program(struct blk_keyslot_manager *ksm,
+					       const struct blk_crypto_key *key,
+					       unsigned int slot)
 {
-	struct blk_crypto_keyslot *slotp = &blk_crypto_keyslots[slot];
+	struct blk_crypto_fallback_keyslot *slotp = &blk_crypto_keyslots[slot];
 	const enum blk_crypto_mode_num crypto_mode =
 						key->crypto_cfg.crypto_mode;
 	int err;
 
 	if (crypto_mode != slotp->crypto_mode &&
 	    slotp->crypto_mode != BLK_ENCRYPTION_MODE_INVALID)
-		blk_crypto_evict_keyslot(slot);
+		blk_crypto_fallback_evict_keyslot(slot);
 
 	slotp->crypto_mode = crypto_mode;
 	err = crypto_skcipher_setkey(slotp->tfms[crypto_mode], key->raw,
 				     key->size);
 	if (err) {
-		blk_crypto_evict_keyslot(slot);
+		blk_crypto_fallback_evict_keyslot(slot);
 		return err;
 	}
 	return 0;
 }
 
-static int blk_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
-				    const struct blk_crypto_key *key,
-				    unsigned int slot)
+static int blk_crypto_fallback_keyslot_evict(struct blk_keyslot_manager *ksm,
+					     const struct blk_crypto_key *key,
+					     unsigned int slot)
 {
-	blk_crypto_evict_keyslot(slot);
+	blk_crypto_fallback_evict_keyslot(slot);
 	return 0;
 }
 
@@ -140,8 +140,8 @@ static int blk_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
  * hardware.
  */
 static const struct blk_ksm_ll_ops blk_crypto_ksm_ll_ops = {
-	.keyslot_program	= blk_crypto_keyslot_program,
-	.keyslot_evict		= blk_crypto_keyslot_evict,
+	.keyslot_program	= blk_crypto_fallback_keyslot_program,
+	.keyslot_evict		= blk_crypto_fallback_keyslot_evict,
 };
 
 static void blk_crypto_fallback_encrypt_endio(struct bio *enc_bio)
@@ -159,7 +159,7 @@ static void blk_crypto_fallback_encrypt_endio(struct bio *enc_bio)
 	bio_endio(src_bio);
 }
 
-static struct bio *blk_crypto_clone_bio(struct bio *bio_src)
+static struct bio *blk_crypto_fallback_clone_bio(struct bio *bio_src)
 {
 	struct bvec_iter iter;
 	struct bio_vec bv;
@@ -186,12 +186,13 @@ static struct bio *blk_crypto_clone_bio(struct bio *bio_src)
 	return bio;
 }
 
-static bool blk_crypto_alloc_cipher_req(struct blk_ksm_keyslot *slot,
-					struct skcipher_request **ciph_req_ret,
-					struct crypto_wait *wait)
+static bool
+blk_crypto_fallback_alloc_cipher_req(struct blk_ksm_keyslot *slot,
+				     struct skcipher_request **ciph_req_ret,
+				     struct crypto_wait *wait)
 {
 	struct skcipher_request *ciph_req;
-	const struct blk_crypto_keyslot *slotp;
+	const struct blk_crypto_fallback_keyslot *slotp;
 	int keyslot_idx = blk_ksm_get_slot_idx(slot);
 
 	slotp = &blk_crypto_keyslots[keyslot_idx];
@@ -209,7 +210,7 @@ static bool blk_crypto_alloc_cipher_req(struct blk_ksm_keyslot *slot,
 	return true;
 }
 
-static bool blk_crypto_split_bio_if_needed(struct bio **bio_ptr)
+static bool blk_crypto_fallback_split_bio_if_needed(struct bio **bio_ptr)
 {
 	struct bio *bio = *bio_ptr;
 	unsigned int i = 0;
@@ -276,7 +277,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 	blk_status_t blk_st;
 
 	/* Split the bio if it's too big for single page bvec */
-	if (!blk_crypto_split_bio_if_needed(bio_ptr))
+	if (!blk_crypto_fallback_split_bio_if_needed(bio_ptr))
 		return false;
 
 	src_bio = *bio_ptr;
@@ -284,7 +285,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 	data_unit_size = bc->bc_key->crypto_cfg.data_unit_size;
 
 	/* Allocate bounce bio for encryption */
-	enc_bio = blk_crypto_clone_bio(src_bio);
+	enc_bio = blk_crypto_fallback_clone_bio(src_bio);
 	if (!enc_bio) {
 		src_bio->bi_status = BLK_STS_RESOURCE;
 		return false;
@@ -301,7 +302,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 	}
 
 	/* and then allocate an skcipher_request for it */
-	if (!blk_crypto_alloc_cipher_req(slot, &ciph_req, &wait)) {
+	if (!blk_crypto_fallback_alloc_cipher_req(slot, &ciph_req, &wait)) {
 		src_bio->bi_status = BLK_STS_RESOURCE;
 		goto out_release_keyslot;
 	}
@@ -403,7 +404,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
 	}
 
 	/* and then allocate an skcipher_request for it */
-	if (!blk_crypto_alloc_cipher_req(slot, &ciph_req, &wait)) {
+	if (!blk_crypto_fallback_alloc_cipher_req(slot, &ciph_req, &wait)) {
 		bio->bi_status = BLK_STS_RESOURCE;
 		goto out;
 	}
@@ -473,9 +474,9 @@ static void blk_crypto_fallback_decrypt_endio(struct bio *bio)
  * @bio_ptr: pointer to the bio to prepare
  *
  * If bio is doing a WRITE operation, this splits the bio into two parts if it's
- * too big (see blk_crypto_split_bio_if_needed). It then allocates a bounce bio
- * for the first part, encrypts it, and update bio_ptr to point to the bounce
- * bio.
+ * too big (see blk_crypto_fallback_split_bio_if_needed()). It then allocates a
+ * bounce bio for the first part, encrypts it, and updates bio_ptr to point to
+ * the bounce bio.
  *
  * For a READ operation, we mark the bio for decryption by using bi_private and
  * bi_end_io.
@@ -610,7 +611,7 @@ static int blk_crypto_fallback_init(void)
 int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
 {
 	const char *cipher_str = blk_crypto_modes[mode_num].cipher_str;
-	struct blk_crypto_keyslot *slotp;
+	struct blk_crypto_fallback_keyslot *slotp;
 	unsigned int i;
 	int err = 0;
 
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Reviewed-by on v2 1/4
#2 lore raw

Re: [PATCH v2 1/4] blk-crypto-fallback: properly prefix function and struct names

Quoted 10 lines · Eric Biggers

External email: Use caution opening links or attachments

From: Eric Biggers <[email protected]>

For clarity, avoid using just the "blk_crypto_" prefix for functions and structs that are specific to blk-crypto-fallback. Instead, use "blk_crypto_fallback_". Some places already did this, but others didn't.

Quoted 6 lines

This is also a prerequisite for using "struct blk_crypto_keyslot" to mean a generic blk-crypto keyslot (which is what it sounds like). Rename the fallback one to "struct blk_crypto_fallback_keyslot".

Looks good, it might be useful to mention this patch doesn't change any functionality, not a hard requirement though.

#3 lore raw

PATCH v2 2/4 blk-crypto: rename keyslot-manager files to blk-crypto-profile

In reply to Eric Biggers

From: Eric Biggers <[email protected]>

In preparation for renaming struct blk_keyslot_manager to struct blk_crypto_profile, rename the keyslot-manager.h and keyslot-manager.c source files. Renaming these files separately before making a lot of changes to their contents makes it easier for git to understand that they were renamed.

---
 block/Makefile                                            | 2 +-
 block/blk-crypto-fallback.c                               | 2 +-
 block/{keyslot-manager.c => blk-crypto-profile.c}         | 2 +-
 block/blk-crypto.c                                        | 2 +-
 drivers/md/dm-core.h                                      | 2 +-
 drivers/md/dm.c                                           | 2 +-
 drivers/mmc/host/cqhci-crypto.c                           | 2 +-
 drivers/scsi/ufs/ufshcd.h                                 | 2 +-
 include/linux/{keyslot-manager.h => blk-crypto-profile.h} | 0
 include/linux/mmc/host.h                                  | 2 +-
 10 files changed, 9 insertions(+), 9 deletions(-)
 rename block/{keyslot-manager.c => blk-crypto-profile.c} (99%)
 rename include/linux/{keyslot-manager.h => blk-crypto-profile.h} (100%)
block/Makefile +1 -1
index 41aa1ba69c900..c245e05b67453 100644
@@ -36,6 +36,6 @@ obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
-obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= keyslot-manager.o blk-crypto.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o
 obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK)	+= blk-crypto-fallback.o
 obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED)	+= holder.o
block/blk-crypto-fallback.c +1 -1
index 82b302597b474..b3920e8efd075 100644
@@ -12,9 +12,9 @@
 #include <crypto/skcipher.h>
 #include <linux/blk-cgroup.h>
 #include <linux/blk-crypto.h>
+#include <linux/blk-crypto-profile.h>
 #include <linux/blkdev.h>
 #include <linux/crypto.h>
-#include <linux/keyslot-manager.h>
 #include <linux/mempool.h>
 #include <linux/module.h>
 #include <linux/random.h>
block/blk-crypto-profile.c renamed from block/keyslot-manager.c +1 -1
similarity index 99%
rename from block/keyslot-manager.c
rename to block/blk-crypto-profile.c
index 2c4a55bea6ca1..a58daf93c9ba6 100644
@@ -28,7 +28,7 @@
 
 #define pr_fmt(fmt) "blk-crypto: " fmt
 
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 #include <linux/device.h>
 #include <linux/atomic.h>
 #include <linux/mutex.h>
block/blk-crypto.c +1 -1
index 103c2e2d50d67..9102803d36232 100644
@@ -11,7 +11,7 @@
 
 #include <linux/bio.h>
 #include <linux/blkdev.h>
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 
drivers/md/dm-core.h +1 -1
index 55dccdfbcb22e..841ed87999e79 100644
@@ -13,7 +13,7 @@
 #include <linux/ktime.h>
 #include <linux/genhd.h>
 #include <linux/blk-mq.h>
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 
 #include <trace/events/block.h>
 
drivers/md/dm.c +1 -1
index a011d09cb0fac..249223e20d3d0 100644
@@ -29,7 +29,7 @@
 #include <linux/refcount.h>
 #include <linux/part_stat.h>
 #include <linux/blk-crypto.h>
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 
 #define DM_MSG_PREFIX "core"
 
drivers/mmc/host/cqhci-crypto.c +1 -1
index 6419cfbb4ab78..628bbfaf83124 100644
@@ -6,7 +6,7 @@
  */
 
 #include <linux/blk-crypto.h>
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 #include <linux/mmc/host.h>
 
 #include "cqhci-crypto.h"
drivers/scsi/ufs/ufshcd.h +1 -1
index 52ea6f350b181..0f9cbe74642fe 100644
@@ -32,7 +32,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/bitfield.h>
 #include <linux/devfreq.h>
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 #include "unipro.h"
 
 #include <asm/irq.h>
include/linux/blk-crypto-profile.h renamed from include/linux/keyslot-manager.h +0 -0
similarity index 100%
rename from include/linux/keyslot-manager.h
rename to include/linux/blk-crypto-profile.h
include/linux/mmc/host.h +1 -1
index 0c0c9a0fdf578..725b1de417673 100644
@@ -15,7 +15,7 @@
 #include <linux/mmc/card.h>
 #include <linux/mmc/pm.h>
 #include <linux/dma-direction.h>
-#include <linux/keyslot-manager.h>
+#include <linux/blk-crypto-profile.h>
 
 struct mmc_ios {
 	unsigned int	clock;			/* clock rate */
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#4 lore raw

PATCH v2 3/4 blk-crypto: rename blk_keyslot_manager to blk_crypto_profile

In reply to Eric Biggers

From: Eric Biggers <[email protected]>

blk_keyslot_manager is misnamed because it doesn't necessarily manage keyslots. It actually does several different things:

- Contains the crypto capabilities of the device.

- Provides functions to control the inline encryption hardware. Originally these were just for programming/evicting keyslots; however, new functionality (hardware-wrapped keys) will require new functions here which are unrelated to keyslots. Moreover, device-mapper devices already (ab)use "keyslot_evict" to pass key eviction requests to their underlying devices even though device-mapper devices don't have any keyslots themselves (so it really should be "evict_key", not "keyslot_evict").

- Sometimes (but not always!) it manages keyslots. Originally it always did, but device-mapper devices don't have keyslots themselves, so they use a "passthrough keyslot manager" which doesn't actually manage keyslots. This hack works, but the terminology is unnatural. Also, some hardware doesn't have keyslots and thus also uses a "passthrough keyslot manager" (support for such hardware is yet to be upstreamed, but it will happen eventually).

Let's stop having keyslot managers which don't actually manage keyslots. Instead, rename blk_keyslot_manager to blk_crypto_profile.

This is a fairly big change, since for consistency it also has to update keyslot manager-related function names, variable names, and comments -- not just the actual struct name. However it's still a fairly straightforward change, as it doesn't change any actual functionality.

---
 block/blk-crypto-fallback.c        |  71 ++--
 block/blk-crypto-profile.c         | 518 ++++++++++++++---------------
 block/blk-crypto.c                 |  27 +-
 block/blk-integrity.c              |   4 +-
 drivers/md/dm-core.h               |   2 +-
 drivers/md/dm-table.c              | 168 +++++-----
 drivers/md/dm.c                    |   8 +-
 drivers/mmc/core/crypto.c          |  11 +-
 drivers/mmc/host/cqhci-crypto.c    |  31 +-
 drivers/scsi/ufs/ufshcd-crypto.c   |  32 +-
 drivers/scsi/ufs/ufshcd-crypto.h   |   9 +-
 drivers/scsi/ufs/ufshcd.c          |   2 +-
 drivers/scsi/ufs/ufshcd.h          |   4 +-
 include/linux/blk-crypto-profile.h | 164 +++++----
 include/linux/blkdev.h             |  18 +-
 include/linux/device-mapper.h      |   4 +-
 include/linux/mmc/host.h           |   2 +-
 17 files changed, 554 insertions(+), 521 deletions(-)
block/blk-crypto-fallback.c +35 -36
index b3920e8efd075..241d262ccaffe 100644
@@ -77,7 +77,7 @@ static struct blk_crypto_fallback_keyslot {
 	struct crypto_skcipher *tfms[BLK_ENCRYPTION_MODE_MAX];
 } *blk_crypto_keyslots;
 
-static struct blk_keyslot_manager blk_crypto_ksm;
+static struct blk_crypto_profile blk_crypto_fallback_profile;
 static struct workqueue_struct *blk_crypto_wq;
 static mempool_t *blk_crypto_bounce_page_pool;
 static struct bio_set crypto_bio_split;
@@ -103,9 +103,10 @@ static void blk_crypto_fallback_evict_keyslot(unsigned int slot)
 	slotp->crypto_mode = BLK_ENCRYPTION_MODE_INVALID;
 }
 
-static int blk_crypto_fallback_keyslot_program(struct blk_keyslot_manager *ksm,
-					       const struct blk_crypto_key *key,
-					       unsigned int slot)
+static int
+blk_crypto_fallback_keyslot_program(struct blk_crypto_profile *profile,
+				    const struct blk_crypto_key *key,
+				    unsigned int slot)
 {
 	struct blk_crypto_fallback_keyslot *slotp = &blk_crypto_keyslots[slot];
 	const enum blk_crypto_mode_num crypto_mode =
@@ -126,7 +127,7 @@ static int blk_crypto_fallback_keyslot_program(struct blk_keyslot_manager *ksm,
 	return 0;
 }
 
-static int blk_crypto_fallback_keyslot_evict(struct blk_keyslot_manager *ksm,
+static int blk_crypto_fallback_keyslot_evict(struct blk_crypto_profile *profile,
 					     const struct blk_crypto_key *key,
 					     unsigned int slot)
 {
@@ -134,14 +135,9 @@ static int blk_crypto_fallback_keyslot_evict(struct blk_keyslot_manager *ksm,
 	return 0;
 }
 
-/*
- * The crypto API fallback KSM ops - only used for a bio when it specifies a
- * blk_crypto_key that was not supported by the device's inline encryption
- * hardware.
- */
-static const struct blk_ksm_ll_ops blk_crypto_ksm_ll_ops = {
-	.keyslot_program	= blk_crypto_fallback_keyslot_program,
-	.keyslot_evict		= blk_crypto_fallback_keyslot_evict,
+static const struct blk_crypto_ll_ops blk_crypto_fallback_ll_ops = {
+	.keyslot_program        = blk_crypto_fallback_keyslot_program,
+	.keyslot_evict          = blk_crypto_fallback_keyslot_evict,
 };
 
 static void blk_crypto_fallback_encrypt_endio(struct bio *enc_bio)
@@ -187,13 +183,13 @@ static struct bio *blk_crypto_fallback_clone_bio(struct bio *bio_src)
 }
 
 static bool
-blk_crypto_fallback_alloc_cipher_req(struct blk_ksm_keyslot *slot,
+blk_crypto_fallback_alloc_cipher_req(struct blk_crypto_keyslot *slot,
 				     struct skcipher_request **ciph_req_ret,
 				     struct crypto_wait *wait)
 {
 	struct skcipher_request *ciph_req;
 	const struct blk_crypto_fallback_keyslot *slotp;
-	int keyslot_idx = blk_ksm_get_slot_idx(slot);
+	int keyslot_idx = blk_crypto_keyslot_index(slot);
 
 	slotp = &blk_crypto_keyslots[keyslot_idx];
 	ciph_req = skcipher_request_alloc(slotp->tfms[slotp->crypto_mode],
@@ -265,7 +261,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 {
 	struct bio *src_bio, *enc_bio;
 	struct bio_crypt_ctx *bc;
-	struct blk_ksm_keyslot *slot;
+	struct blk_crypto_keyslot *slot;
 	int data_unit_size;
 	struct skcipher_request *ciph_req = NULL;
 	DECLARE_CRYPTO_WAIT(wait);
@@ -292,10 +288,11 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 	}
 
 	/*
-	 * Use the crypto API fallback keyslot manager to get a crypto_skcipher
-	 * for the algorithm and key specified for this bio.
+	 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
+	 * this bio's algorithm and key.
 	 */
-	blk_st = blk_ksm_get_slot_for_key(&blk_crypto_ksm, bc->bc_key, &slot);
+	blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+					bc->bc_key, &slot);
 	if (blk_st != BLK_STS_OK) {
 		src_bio->bi_status = blk_st;
 		goto out_put_enc_bio;
@@ -363,7 +360,7 @@ static bool blk_crypto_fallback_encrypt_bio(struct bio **bio_ptr)
 out_free_ciph_req:
 	skcipher_request_free(ciph_req);
 out_release_keyslot:
-	blk_ksm_put_slot(slot);
+	blk_crypto_put_keyslot(slot);
 out_put_enc_bio:
 	if (enc_bio)
 		bio_put(enc_bio);
@@ -381,7 +378,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
 		container_of(work, struct bio_fallback_crypt_ctx, work);
 	struct bio *bio = f_ctx->bio;
 	struct bio_crypt_ctx *bc = &f_ctx->crypt_ctx;
-	struct blk_ksm_keyslot *slot;
+	struct blk_crypto_keyslot *slot;
 	struct skcipher_request *ciph_req = NULL;
 	DECLARE_CRYPTO_WAIT(wait);
 	u64 curr_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
@@ -394,10 +391,11 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
 	blk_status_t blk_st;
 
 	/*
-	 * Use the crypto API fallback keyslot manager to get a crypto_skcipher
-	 * for the algorithm and key specified for this bio.
+	 * Get a blk-crypto-fallback keyslot that contains a crypto_skcipher for
+	 * this bio's algorithm and key.
 	 */
-	blk_st = blk_ksm_get_slot_for_key(&blk_crypto_ksm, bc->bc_key, &slot);
+	blk_st = blk_crypto_get_keyslot(&blk_crypto_fallback_profile,
+					bc->bc_key, &slot);
 	if (blk_st != BLK_STS_OK) {
 		bio->bi_status = blk_st;
 		goto out_no_keyslot;
@@ -435,7 +433,7 @@ static void blk_crypto_fallback_decrypt_bio(struct work_struct *work)
 
 out:
 	skcipher_request_free(ciph_req);
-	blk_ksm_put_slot(slot);
+	blk_crypto_put_keyslot(slot);
 out_no_keyslot:
 	mempool_free(f_ctx, bio_fallback_crypt_ctx_pool);
 	bio_endio(bio);
@@ -500,8 +498,8 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 		return false;
 	}
 
-	if (!blk_ksm_crypto_cfg_supported(&blk_crypto_ksm,
-					  &bc->bc_key->crypto_cfg)) {
+	if (!__blk_crypto_cfg_supported(&blk_crypto_fallback_profile,
+					&bc->bc_key->crypto_cfg)) {
 		bio->bi_status = BLK_STS_NOTSUPP;
 		return false;
 	}
@@ -527,7 +525,7 @@ bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 
 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
 {
-	return blk_ksm_evict_key(&blk_crypto_ksm, key);
+	return __blk_crypto_evict_key(&blk_crypto_fallback_profile, key);
 }
 
 static bool blk_crypto_fallback_inited;
@@ -535,6 +533,7 @@ static int blk_crypto_fallback_init(void)
 {
 	int i;
 	int err;
+	struct blk_crypto_profile *profile = &blk_crypto_fallback_profile;
 
 	if (blk_crypto_fallback_inited)
 		return 0;
@@ -545,24 +544,24 @@ static int blk_crypto_fallback_init(void)
 	if (err)
 		goto out;
 
-	err = blk_ksm_init(&blk_crypto_ksm, blk_crypto_num_keyslots);
+	err = blk_crypto_profile_init(profile, blk_crypto_num_keyslots);
 	if (err)
 		goto fail_free_bioset;
 	err = -ENOMEM;
 
-	blk_crypto_ksm.ksm_ll_ops = blk_crypto_ksm_ll_ops;
-	blk_crypto_ksm.max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
+	profile->ll_ops = blk_crypto_fallback_ll_ops;
+	profile->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
 
 	/* All blk-crypto modes have a crypto API fallback. */
 	for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++)
-		blk_crypto_ksm.crypto_modes_supported[i] = 0xFFFFFFFF;
-	blk_crypto_ksm.crypto_modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;
+		profile->modes_supported[i] = 0xFFFFFFFF;
+	profile->modes_supported[BLK_ENCRYPTION_MODE_INVALID] = 0;
 
 	blk_crypto_wq = alloc_workqueue("blk_crypto_wq",
 					WQ_UNBOUND | WQ_HIGHPRI |
 					WQ_MEM_RECLAIM, num_online_cpus());
 	if (!blk_crypto_wq)
-		goto fail_free_ksm;
+		goto fail_destroy_profile;
 
 	blk_crypto_keyslots = kcalloc(blk_crypto_num_keyslots,
 				      sizeof(blk_crypto_keyslots[0]),
@@ -596,8 +595,8 @@ static int blk_crypto_fallback_init(void)
 	kfree(blk_crypto_keyslots);
 fail_free_wq:
 	destroy_workqueue(blk_crypto_wq);
-fail_free_ksm:
-	blk_ksm_destroy(&blk_crypto_ksm);
+fail_destroy_profile:
+	blk_crypto_profile_destroy(profile);
 fail_free_bioset:
 	bioset_exit(&crypto_bio_split);
 out:
block/blk-crypto-profile.c +252 -266

809 lines not on this page · raw message

block/blk-crypto.c +14 -13
index 9102803d36232..b14c258ab8cd9 100644
@@ -218,8 +218,9 @@ static bool bio_crypt_check_alignment(struct bio *bio)
 
 blk_status_t __blk_crypto_init_request(struct request *rq)
 {
-	return blk_ksm_get_slot_for_key(rq->q->ksm, rq->crypt_ctx->bc_key,
-					&rq->crypt_keyslot);
+	return blk_crypto_get_keyslot(rq->q->crypto_profile,
+				      rq->crypt_ctx->bc_key,
+				      &rq->crypt_keyslot);
 }
 
 /**
@@ -233,7 +234,7 @@ blk_status_t __blk_crypto_init_request(struct request *rq)
  */
 void __blk_crypto_free_request(struct request *rq)
 {
-	blk_ksm_put_slot(rq->crypt_keyslot);
+	blk_crypto_put_keyslot(rq->crypt_keyslot);
 	mempool_free(rq->crypt_ctx, bio_crypt_ctx_pool);
 	blk_crypto_rq_set_defaults(rq);
 }
@@ -264,6 +265,7 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr)
 {
 	struct bio *bio = *bio_ptr;
 	const struct blk_crypto_key *bc_key = bio->bi_crypt_context->bc_key;
+	struct blk_crypto_profile *profile;
 
 	/* Error if bio has no data. */
 	if (WARN_ON_ONCE(!bio_has_data(bio))) {
@@ -280,8 +282,8 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr)
 	 * Success if device supports the encryption context, or if we succeeded
 	 * in falling back to the crypto API.
 	 */
-	if (blk_ksm_crypto_cfg_supported(bio->bi_bdev->bd_disk->queue->ksm,
-					 &bc_key->crypto_cfg))
+	profile = bio->bi_bdev->bd_disk->queue->crypto_profile;
+	if (__blk_crypto_cfg_supported(profile, &bc_key->crypto_cfg))
 		return true;
 
 	if (blk_crypto_fallback_bio_prep(bio_ptr))
@@ -357,7 +359,7 @@ bool blk_crypto_config_supported(struct request_queue *q,
 				 const struct blk_crypto_config *cfg)
 {
 	return IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) ||
-	       blk_ksm_crypto_cfg_supported(q->ksm, cfg);
+	       __blk_crypto_cfg_supported(q->crypto_profile, cfg);
 }
 
 /**
@@ -378,7 +380,7 @@ bool blk_crypto_config_supported(struct request_queue *q,
 int blk_crypto_start_using_key(const struct blk_crypto_key *key,
 			       struct request_queue *q)
 {
-	if (blk_ksm_crypto_cfg_supported(q->ksm, &key->crypto_cfg))
+	if (__blk_crypto_cfg_supported(q->crypto_profile, &key->crypto_cfg))
 		return 0;
 	return blk_crypto_fallback_start_using_mode(key->crypto_cfg.crypto_mode);
 }
@@ -394,18 +396,17 @@ int blk_crypto_start_using_key(const struct blk_crypto_key *key,
  * evicted from any hardware that it might have been programmed into.  The key
  * must not be in use by any in-flight IO when this function is called.
  *
- * Return: 0 on success or if key is not present in the q's ksm, -err on error.
+ * Return: 0 on success or if the key wasn't in any keyslot; -errno on error.
  */
 int blk_crypto_evict_key(struct request_queue *q,
 			 const struct blk_crypto_key *key)
 {
-	if (blk_ksm_crypto_cfg_supported(q->ksm, &key->crypto_cfg))
-		return blk_ksm_evict_key(q->ksm, key);
+	if (__blk_crypto_cfg_supported(q->crypto_profile, &key->crypto_cfg))
+		return __blk_crypto_evict_key(q->crypto_profile, key);
 
 	/*
-	 * If the request queue's associated inline encryption hardware didn't
-	 * have support for the key, then the key might have been programmed
-	 * into the fallback keyslot manager, so try to evict from there.
+	 * If the request_queue didn't support the key, then blk-crypto-fallback
+	 * may have been used, so try to evict the key from blk-crypto-fallback.
 	 */
 	return blk_crypto_fallback_evict_key(key);
 }
block/blk-integrity.c +2 -2
index 69a12177dfb62..60a907f49cc28 100644
@@ -409,9 +409,9 @@ void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template
 	blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue);
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
-	if (disk->queue->ksm) {
+	if (disk->queue->crypto_profile) {
 		pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n");
-		blk_ksm_unregister(disk->queue);
+		blk_crypto_unregister(disk->queue);
 	}
 #endif
 }
drivers/md/dm-core.h +1 -1
index 841ed87999e79..b855fef4f38a6 100644
@@ -200,7 +200,7 @@ struct dm_table {
 	struct dm_md_mempools *mempools;
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
-	struct blk_keyslot_manager *ksm;
+	struct blk_crypto_profile *crypto_profile;
 #endif
 };
 
drivers/md/dm-table.c +82 -86

283 lines not on this page · raw message

drivers/md/dm.c +4 -4
index 249223e20d3d0..f5b4f40a7fd63 100644
@@ -1668,14 +1668,14 @@ static const struct dax_operations dm_dax_ops;
 static void dm_wq_work(struct work_struct *work);
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
-static void dm_queue_destroy_keyslot_manager(struct request_queue *q)
+static void dm_queue_destroy_crypto_profile(struct request_queue *q)
 {
-	dm_destroy_keyslot_manager(q->ksm);
+	dm_destroy_crypto_profile(q->crypto_profile);
 }
 
 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
 
-static inline void dm_queue_destroy_keyslot_manager(struct request_queue *q)
+static inline void dm_queue_destroy_crypto_profile(struct request_queue *q)
 {
 }
 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
@@ -1701,7 +1701,7 @@ static void cleanup_mapped_device(struct mapped_device *md)
 			dm_sysfs_exit(md);
 			del_gendisk(md->disk);
 		}
-		dm_queue_destroy_keyslot_manager(md->queue);
+		dm_queue_destroy_crypto_profile(md->queue);
 		blk_cleanup_disk(md->disk);
 	}
 
drivers/mmc/core/crypto.c +7 -4
index 67557808cada5..fec4fbf16a5b6 100644
@@ -16,13 +16,13 @@ void mmc_crypto_set_initial_state(struct mmc_host *host)
 {
 	/* Reset might clear all keys, so reprogram all the keys. */
 	if (host->caps2 & MMC_CAP2_CRYPTO)
-		blk_ksm_reprogram_all_keys(&host->ksm);
+		blk_crypto_reprogram_all_keys(&host->crypto_profile);
 }
 
 void mmc_crypto_setup_queue(struct request_queue *q, struct mmc_host *host)
 {
 	if (host->caps2 & MMC_CAP2_CRYPTO)
-		blk_ksm_register(&host->ksm, q);
+		blk_crypto_register(&host->crypto_profile, q);
 }
 EXPORT_SYMBOL_GPL(mmc_crypto_setup_queue);
 
@@ -30,12 +30,15 @@ void mmc_crypto_prepare_req(struct mmc_queue_req *mqrq)
 {
 	struct request *req = mmc_queue_req_to_req(mqrq);
 	struct mmc_request *mrq = &mqrq->brq.mrq;
+	struct blk_crypto_keyslot *keyslot;
 
 	if (!req->crypt_ctx)
 		return;
 
 	mrq->crypto_ctx = req->crypt_ctx;
-	if (req->crypt_keyslot)
-		mrq->crypto_key_slot = blk_ksm_get_slot_idx(req->crypt_keyslot);
+
+	keyslot = req->crypt_keyslot;
+	if (keyslot)
+		mrq->crypto_key_slot = blk_crypto_keyslot_index(keyslot);
 }
 EXPORT_SYMBOL_GPL(mmc_crypto_prepare_req);
drivers/mmc/host/cqhci-crypto.c +16 -15
index 628bbfaf83124..d5f4b6972f63e 100644
@@ -23,9 +23,10 @@ static const struct cqhci_crypto_alg_entry {
 };
 
 static inline struct cqhci_host *
-cqhci_host_from_ksm(struct blk_keyslot_manager *ksm)
+cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
 {
-	struct mmc_host *mmc = container_of(ksm, struct mmc_host, ksm);
+	struct mmc_host *mmc =
+		container_of(profile, struct mmc_host, crypto_profile);
 
 	return mmc->cqe_private;
 }
@@ -57,12 +58,12 @@ static int cqhci_crypto_program_key(struct cqhci_host *cq_host,
 	return 0;
 }
 
-static int cqhci_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
+static int cqhci_crypto_keyslot_program(struct blk_crypto_profile *profile,
 					const struct blk_crypto_key *key,
 					unsigned int slot)
 
 {
-	struct cqhci_host *cq_host = cqhci_host_from_ksm(ksm);
+	struct cqhci_host *cq_host = cqhci_host_from_crypto_profile(profile);
 	const union cqhci_crypto_cap_entry *ccap_array =
 		cq_host->crypto_cap_array;
 	const struct cqhci_crypto_alg_entry *alg =
@@ -115,11 +116,11 @@ static int cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)
 	return cqhci_crypto_program_key(cq_host, &cfg, slot);
 }
 
-static int cqhci_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
+static int cqhci_crypto_keyslot_evict(struct blk_crypto_profile *profile,
 				      const struct blk_crypto_key *key,
 				      unsigned int slot)
 {
-	struct cqhci_host *cq_host = cqhci_host_from_ksm(ksm);
+	struct cqhci_host *cq_host = cqhci_host_from_crypto_profile(profile);
 
 	return cqhci_crypto_clear_keyslot(cq_host, slot);
 }
@@ -132,7 +133,7 @@ static int cqhci_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
  * "enabled" when these are called, i.e. CQHCI_ENABLE might not be set in the
  * CQHCI_CFG register.  But the hardware allows that.
  */
-static const struct blk_ksm_ll_ops cqhci_ksm_ops = {
+static const struct blk_crypto_ll_ops cqhci_crypto_ops = {
 	.keyslot_program	= cqhci_crypto_keyslot_program,
 	.keyslot_evict		= cqhci_crypto_keyslot_evict,
 };
@@ -157,8 +158,8 @@ cqhci_find_blk_crypto_mode(union cqhci_crypto_cap_entry cap)
  *
  * If the driver previously set MMC_CAP2_CRYPTO and the CQE declares
  * CQHCI_CAP_CS, initialize the crypto support.  This involves reading the
- * crypto capability registers, initializing the keyslot manager, clearing all
- * keyslots, and enabling 128-bit task descriptors.
+ * crypto capability registers, initializing the blk_crypto_profile, clearing
+ * all keyslots, and enabling 128-bit task descriptors.
  *
  * Return: 0 if crypto was initialized or isn't supported; whether
  *	   MMC_CAP2_CRYPTO remains set indicates which one of those cases it is.
@@ -168,7 +169,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 {
 	struct mmc_host *mmc = cq_host->mmc;
 	struct device *dev = mmc_dev(mmc);
-	struct blk_keyslot_manager *ksm = &mmc->ksm;
+	struct blk_crypto_profile *profile = &mmc->crypto_profile;
 	unsigned int num_keyslots;
 	unsigned int cap_idx;
 	enum blk_crypto_mode_num blk_mode_num;
@@ -199,15 +200,15 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	 */
 	num_keyslots = cq_host->crypto_capabilities.config_count + 1;
 
-	err = devm_blk_ksm_init(dev, ksm, num_keyslots);
+	err = devm_blk_crypto_profile_init(dev, profile, num_keyslots);
 	if (err)
 		goto out;
 
-	ksm->ksm_ll_ops = cqhci_ksm_ops;
-	ksm->dev = dev;
+	profile->ll_ops = cqhci_crypto_ops;
+	profile->dev = dev;
 
 	/* Unfortunately, CQHCI crypto only supports 32 DUN bits. */
-	ksm->max_dun_bytes_supported = 4;
+	profile->max_dun_bytes_supported = 4;
 
 	/*
 	 * Cache all the crypto capabilities and advertise the supported crypto
@@ -223,7 +224,7 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 					cq_host->crypto_cap_array[cap_idx]);
 		if (blk_mode_num == BLK_ENCRYPTION_MODE_INVALID)
 			continue;
-		ksm->crypto_modes_supported[blk_mode_num] |=
+		profile->modes_supported[blk_mode_num] |=
 			cq_host->crypto_cap_array[cap_idx].sdus_mask * 512;
 	}
 
drivers/scsi/ufs/ufshcd-crypto.c +17 -15
index d70cdcd35e435..67402baf6faee 100644
@@ -48,11 +48,12 @@ static int ufshcd_program_key(struct ufs_hba *hba,
 	return err;
 }
 
-static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
+static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
 					 const struct blk_crypto_key *key,
 					 unsigned int slot)
 {
-	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+	struct ufs_hba *hba =
+		container_of(profile, struct ufs_hba, crypto_profile);
 	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
 	const struct ufs_crypto_alg_entry *alg =
 			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
@@ -105,11 +106,12 @@ static int ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
 	return ufshcd_program_key(hba, &cfg, slot);
 }
 
-static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
+static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
 				       const struct blk_crypto_key *key,
 				       unsigned int slot)
 {
-	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+	struct ufs_hba *hba =
+		container_of(profile, struct ufs_hba, crypto_profile);
 
 	return ufshcd_clear_keyslot(hba, slot);
 }
@@ -120,11 +122,11 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
 		return false;
 
 	/* Reset might clear all keys, so reprogram all the keys. */
-	blk_ksm_reprogram_all_keys(&hba->ksm);
+	blk_crypto_reprogram_all_keys(&hba->crypto_profile);
 	return true;
 }
 
-static const struct blk_ksm_ll_ops ufshcd_ksm_ops = {
+static const struct blk_crypto_ll_ops ufshcd_crypto_ops = {
 	.keyslot_program	= ufshcd_crypto_keyslot_program,
 	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
 };
@@ -179,15 +181,16 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 	}
 
 	/* The actual number of configurations supported is (CFGC+1) */
-	err = devm_blk_ksm_init(hba->dev, &hba->ksm,
-				hba->crypto_capabilities.config_count + 1);
+	err = devm_blk_crypto_profile_init(
+			hba->dev, &hba->crypto_profile,
+			hba->crypto_capabilities.config_count + 1);
 	if (err)
 		goto out;
 
-	hba->ksm.ksm_ll_ops = ufshcd_ksm_ops;
+	hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
 	/* UFS only supports 8 bytes for any DUN */
-	hba->ksm.max_dun_bytes_supported = 8;
-	hba->ksm.dev = hba->dev;
+	hba->crypto_profile.max_dun_bytes_supported = 8;
+	hba->crypto_profile.dev = hba->dev;
 
 	/*
 	 * Cache all the UFS crypto capabilities and advertise the supported
@@ -202,7 +205,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 		blk_mode_num = ufshcd_find_blk_crypto_mode(
 						hba->crypto_cap_array[cap_idx]);
 		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
-			hba->ksm.crypto_modes_supported[blk_mode_num] |=
+			hba->crypto_profile.modes_supported[blk_mode_num] |=
 				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
 	}
 
@@ -230,9 +233,8 @@ void ufshcd_init_crypto(struct ufs_hba *hba)
 		ufshcd_clear_keyslot(hba, slot);
 }
 
-void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
-					    struct request_queue *q)
+void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
 {
 	if (hba->caps & UFSHCD_CAP_CRYPTO)
-		blk_ksm_register(&hba->ksm, q);
+		blk_crypto_register(&hba->crypto_profile, q);
 }
drivers/scsi/ufs/ufshcd-crypto.h +4 -5
index 78a58e788dff9..e18c012768732 100644
@@ -18,7 +18,7 @@ static inline void ufshcd_prepare_lrbp_crypto(struct request *rq,
 		return;
 	}
 
-	lrbp->crypto_key_slot = blk_ksm_get_slot_idx(rq->crypt_keyslot);
+	lrbp->crypto_key_slot = blk_crypto_keyslot_index(rq->crypt_keyslot);
 	lrbp->data_unit_num = rq->crypt_ctx->bc_dun[0];
 }
 
@@ -40,8 +40,7 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba);
 
 void ufshcd_init_crypto(struct ufs_hba *hba);
 
-void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
-					    struct request_queue *q);
+void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q);
 
 #else /* CONFIG_SCSI_UFS_CRYPTO */
 
@@ -64,8 +63,8 @@ static inline int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
 
 static inline void ufshcd_init_crypto(struct ufs_hba *hba) { }
 
-static inline void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
-						struct request_queue *q) { }
+static inline void ufshcd_crypto_register(struct ufs_hba *hba,
+					  struct request_queue *q) { }
 
 #endif /* CONFIG_SCSI_UFS_CRYPTO */
 
drivers/scsi/ufs/ufshcd.c +1 -1
index 3841ab49f5560..2782e7e2c9b7e 100644
@@ -5017,7 +5017,7 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
 	else if (ufshcd_is_rpm_autosuspend_allowed(hba))
 		sdev->rpm_autosuspend = 1;
 
-	ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
+	ufshcd_crypto_register(hba, q);
 
 	return 0;
 }
drivers/scsi/ufs/ufshcd.h +2 -2
index 0f9cbe74642fe..df5439b122085 100644
@@ -764,7 +764,7 @@ struct ufs_hba_monitor {
  * @crypto_capabilities: Content of crypto capabilities register (0x100)
  * @crypto_cap_array: Array of crypto capabilities
  * @crypto_cfg_register: Start of the crypto cfg array
- * @ksm: the keyslot manager tied to this hba
+ * @crypto_profile: the crypto profile of this hba (if applicable)
  */
 struct ufs_hba {
 	void __iomem *mmio_base;
@@ -905,7 +905,7 @@ struct ufs_hba {
 	union ufs_crypto_capabilities crypto_capabilities;
 	union ufs_crypto_cap_entry *crypto_cap_array;
 	u32 crypto_cfg_register;
-	struct blk_keyslot_manager ksm;
+	struct blk_crypto_profile crypto_profile;
 #endif
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_root;
include/linux/blk-crypto-profile.h +105 -59

213 lines not on this page · raw message

include/linux/blkdev.h +9 -9
index 12b9dbcc980ee..356567520c725 100644
@@ -37,7 +37,7 @@ struct pr_ops;
 struct rq_qos;
 struct blk_queue_stats;
 struct blk_stat_callback;
-struct blk_keyslot_manager;
+struct blk_crypto_profile;
 
 #define BLKDEV_MIN_RQ	4
 #define BLKDEV_MAX_RQ	128	/* Default maximum */
@@ -211,7 +211,7 @@ struct request {
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 	struct bio_crypt_ctx *crypt_ctx;
-	struct blk_ksm_keyslot *crypt_keyslot;
+	struct blk_crypto_keyslot *crypt_keyslot;
 #endif
 
 	unsigned short write_hint;
@@ -444,8 +444,7 @@ struct request_queue {
 	unsigned int		dma_alignment;
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
-	/* Inline crypto capabilities */
-	struct blk_keyslot_manager *ksm;
+	struct blk_crypto_profile *crypto_profile;
 #endif
 
 	unsigned int		rq_timeout;
@@ -1813,19 +1812,20 @@ static inline struct bio_vec *rq_integrity_vec(struct request *rq)
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 
-bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q);
+bool blk_crypto_register(struct blk_crypto_profile *profile,
+			 struct request_queue *q);
 
-void blk_ksm_unregister(struct request_queue *q);
+void blk_crypto_unregister(struct request_queue *q);
 
 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
 
-static inline bool blk_ksm_register(struct blk_keyslot_manager *ksm,
-				    struct request_queue *q)
+static inline bool blk_crypto_register(struct blk_crypto_profile *profile,
+				       struct request_queue *q)
 {
 	return true;
 }
 
-static inline void blk_ksm_unregister(struct request_queue *q) { }
+static inline void blk_crypto_unregister(struct request_queue *q) { }
 
 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
 
include/linux/device-mapper.h +2 -2
index 114553b487ef4..a7df155ea49b8 100644
@@ -576,9 +576,9 @@ struct dm_table *dm_swap_table(struct mapped_device *md,
 			       struct dm_table *t);
 
 /*
- * Table keyslot manager functions
+ * Table blk_crypto_profile functions
  */
-void dm_destroy_keyslot_manager(struct blk_keyslot_manager *ksm);
+void dm_destroy_crypto_profile(struct blk_crypto_profile *profile);
 
 /*-----------------------------------------------------------------
  * Macros.
include/linux/mmc/host.h +1 -1
index 725b1de417673..52eae8c45b8d6 100644
@@ -492,7 +492,7 @@ struct mmc_host {
 
 	/* Inline encryption support */
 #ifdef CONFIG_MMC_CRYPTO
-	struct blk_keyslot_manager ksm;
+	struct blk_crypto_profile crypto_profile;
 #endif
 
 	/* Host Software Queue support */
Signature · 6 lines
2.33.0

--
dm-devel mailing list
[email protected]
https://listman.redhat.com/mailman/listinfo/dm-devel
#5 lore raw

PATCH v2 4/4 blk-crypto: update inline encryption documentation

In reply to Eric Biggers

From: Eric Biggers <[email protected]>

Rework most of inline-encryption.rst to be easier to follow, to correct some information, to add some important details and remove some unimportant details, and to take into account the renaming from blk_keyslot_manager to blk_crypto_profile.

---
 Documentation/block/inline-encryption.rst | 439 ++++++++++++----------
 1 file changed, 236 insertions(+), 203 deletions(-)
Documentation/block/inline-encryption.rst +236 -203
index 7f9b40d6b416b..2af53915654a9 100644
@@ -8,229 +8,262 @@ Background
 ==========
 
 Inline encryption hardware sits logically between memory and the disk, and can
-en/decrypt data as it goes in/out of the disk. Inline encryption hardware has a
-fixed number of "keyslots" - slots into which encryption contexts (i.e. the
-encryption key, encryption algorithm, data unit size) can be programmed by the
-kernel at any time. Each request sent to the disk can be tagged with the index
-of a keyslot (and also a data unit number to act as an encryption tweak), and
-the inline encryption hardware will en/decrypt the data in the request with the
-encryption context programmed into that keyslot. This is very different from
-full disk encryption solutions like self encrypting drives/TCG OPAL/ATA
-Security standards, since with inline encryption, any block on disk could be
-encrypted with any encryption context the kernel chooses.
-
+en/decrypt data as it goes in/out of the disk.  For each I/O request, software
+can control exactly how the inline encryption hardware will en/decrypt the data
+in terms of key, algorithm, data unit size (the granularity of en/decryption),
+and data unit number (a value that determines the initialization vector(s)).
+
+Some inline encryption hardware accepts the key, algorithm, and data unit size
+directly in I/O requests.  However, most inline encryption hardware instead has
+a fixed number of "keyslots" and requires that the key, algorithm, and data unit
+size first be programmed into a keyslot.  I/O requests then just reference
+keyslot indices.
+
+Note that inline encryption hardware is very different from "self-encrypting
+drives", such as those based on the TCG Opal or ATA Security standards.
+Self-encrypting drives don't provide fine-grained software control of encryption
+and provide no way to verify the correctness of the resulting ciphertext.  In
+contrast, inline encryption hardware provides fine-grained control of
+encryption, including the choice of key and initialization vector for each
+sector, and can be tested for correctness.
 
 Objective
 =========
 
-We want to support inline encryption (IE) in the kernel.
-To allow for testing, we also want a crypto API fallback when actual
-IE hardware is absent. We also want IE to work with layered devices
-like dm and loopback (i.e. we want to be able to use the IE hardware
-of the underlying devices if present, or else fall back to crypto API
-en/decryption).
-
+We want to support inline encryption in the kernel.  To make testing easier, we
+also want support for falling back to the kernel crypto API when actual inline
+encryption hardware is absent.  We also want inline encryption to work with
+layered devices like device-mapper and loopback (i.e. we want to be able to use
+the inline encryption hardware of the underlying devices if present, or else
+fall back to crypto API en/decryption).
 
 Constraints and notes
 =====================
 
-- IE hardware has a limited number of "keyslots" that can be programmed
-  with an encryption context (key, algorithm, data unit size, etc.) at any time.
-  One can specify a keyslot in a data request made to the device, and the
-  device will en/decrypt the data using the encryption context programmed into
-  that specified keyslot. When possible, we want to make multiple requests with
-  the same encryption context share the same keyslot.
-
-- We need a way for upper layers like filesystems to specify an encryption
-  context to use for en/decrypting a struct bio, and a device driver (like UFS)
-  needs to be able to use that encryption context when it processes the bio.
-
-- We need a way for device drivers to expose their inline encryption
-  capabilities in a unified way to the upper layers.
-
-
-Design
-======
-
-We add a struct bio_crypt_ctx to struct bio that can
-represent an encryption context, because we need to be able to pass this
-encryption context from the upper layers (like the fs layer) to the
-device driver to act upon.
-
-While IE hardware works on the notion of keyslots, the FS layer has no
-knowledge of keyslots - it simply wants to specify an encryption context to
-use while en/decrypting a bio.
-
-We introduce a keyslot manager (KSM) that handles the translation from
-encryption contexts specified by the FS to keyslots on the IE hardware.
-This KSM also serves as the way IE hardware can expose its capabilities to
-upper layers. The generic mode of operation is: each device driver that wants
-to support IE will construct a KSM and set it up in its struct request_queue.
-Upper layers that want to use IE on this device can then use this KSM in
-the device's struct request_queue to translate an encryption context into
-a keyslot. The presence of the KSM in the request queue shall be used to mean
-that the device supports IE.
-
-The KSM uses refcounts to track which keyslots are idle (either they have no
-encryption context programmed, or there are no in-flight struct bios
-referencing that keyslot). When a new encryption context needs a keyslot, it
-tries to find a keyslot that has already been programmed with the same
-encryption context, and if there is no such keyslot, it evicts the least
-recently used idle keyslot and programs the new encryption context into that
-one. If no idle keyslots are available, then the caller will sleep until there
-is at least one.
-
-
-blk-mq changes, other block layer changes and blk-crypto-fallback
-=================================================================
-
-We add a pointer to a ``bi_crypt_context`` and ``keyslot`` to
-struct request. These will be referred to as the ``crypto fields``
-for the request. This ``keyslot`` is the keyslot into which the
-``bi_crypt_context`` has been programmed in the KSM of the ``request_queue``
-that this request is being sent to.
-
-We introduce ``block/blk-crypto-fallback.c``, which allows upper layers to remain
-blissfully unaware of whether or not real inline encryption hardware is present
-underneath. When a bio is submitted with a target ``request_queue`` that doesn't
-support the encryption context specified with the bio, the block layer will
-en/decrypt the bio with the blk-crypto-fallback.
-
-If the bio is a ``WRITE`` bio, a bounce bio is allocated, and the data in the bio
-is encrypted stored in the bounce bio - blk-mq will then proceed to process the
-bounce bio as if it were not encrypted at all (except when blk-integrity is
-concerned). ``blk-crypto-fallback`` sets the bounce bio's ``bi_end_io`` to an
-internal function that cleans up the bounce bio and ends the original bio.
-
-If the bio is a ``READ`` bio, the bio's ``bi_end_io`` (and also ``bi_private``)
-is saved and overwritten by ``blk-crypto-fallback`` to
-``bio_crypto_fallback_decrypt_bio``.  The bio's ``bi_crypt_context`` is also
-overwritten with ``NULL``, so that to the rest of the stack, the bio looks
-as if it was a regular bio that never had an encryption context specified.
-``bio_crypto_fallback_decrypt_bio`` will decrypt the bio, restore the original
-``bi_end_io`` (and also ``bi_private``) and end the bio again.
-
-Regardless of whether real inline encryption hardware is used or the
+- We need a way for upper layers (e.g. filesystems) to specify an encryption
+  context to use for en/decrypting a bio, and device drivers (e.g. UFSHCD) need
+  to be able to use that encryption context when they process the request.
+  Encryption contexts also introduce constraints on bio merging; the block layer
+  needs to be aware of these constraints.
+
+- Different inline encryption hardware has different supported algorithms,
+  supported data unit sizes, maximum data unit numbers, etc.  We call these
+  properties the "crypto capabilities".  We need a way for device drivers to
+  advertise crypto capabilities to upper layers in a generic way.
+
+- Inline encryption hardware usually (but not always) requires that keys be
+  programmed into keyslots before being used.  Since programming keyslots may be
+  slow and there may not be very many keyslots, we shouldn't just program the
+  key for every I/O request, but rather keep track of which keys are in the
+  keyslots and reuse an already-programmed keyslot when possible.
+
+- Upper layers typically define a specific end-of-life for crypto keys, e.g.
+  when an encrypted directory is locked or when a crypto mapping is torn down.
+  At these times, keys are wiped from memory.  We must provide a way for upper
+  layers to also evict keys from any keyslots they are present in.
+
+- When possible, device-mapper devices must be able to pass through the inline
+  encryption support of their underlying devices.  However, it doesn't make
+  sense for device-mapper devices to have keyslots themselves.
+
+Basic design
+============
+
+We introduce ``struct blk_crypto_key`` to represent an inline encryption key and
+how it will be used.  This includes the actual bytes of the key; the size of the
+key; the algorithm and data unit size the key will be used with; and the number
+of bytes needed to represent the maximum data unit number the key will be used
+with.
+
+We introduce ``struct bio_crypt_ctx`` to represent an encryption context.  It
+contains a data unit number and a pointer to a blk_crypto_key.  We add pointers
+to a bio_crypt_ctx to ``struct bio`` and ``struct request``; this allows users
+of the block layer (e.g. filesystems) to provide an encryption context when
+creating a bio and have it be passed down the stack for processing by the block
+layer and device drivers.  Note that the encryption context doesn't explicitly
+say whether to encrypt or decrypt, as that is implicit from the direction of the
+bio; WRITE means encrypt, and READ means decrypt.
+
+We also introduce ``struct blk_crypto_profile`` to contain all generic inline
+encryption-related state for a particular inline encryption device.  The
+blk_crypto_profile serves as the way that drivers for inline encryption hardware
+advertise their crypto capabilities and provide certain functions (e.g.,
+functions to program and evict keys) to upper layers.  Each device driver that
+wants to support inline encryption will construct a blk_crypto_profile, then
+associate it with the disk's request_queue.
+
+The blk_crypto_profile also manages the hardware's keyslots, when applicable.
+This happens in the block layer, so that users of the block layer can just
+specify encryption contexts and don't need to know about keyslots at all, nor do
+device drivers need to care about most details of keyslot management.
+
+Specifically, for each keyslot, the block layer (via the blk_crypto_profile)
+keeps track of which blk_crypto_key that keyslot contains (if any), and how many
+in-flight I/O requests are using it.  When the block layer creates a ``struct
+request`` for a bio that has an encryption context, it grabs a keyslot that
+already contains the key if possible.  Otherwise it waits for an idle keyslot (a
+keyslot that was either never used or one that isn't in-use by any I/O), then
+programs the key into the least-recently-used idle keyslot using the function
+the device driver provided.  In both cases, the resulting keyslot is stored in
+the ``crypt_keyslot`` field of the request, where it is then accessible to
+device drivers, and is released after the request completes.
+
+``struct request`` also contains a pointer to the original bio_crypt_ctx, in
+addition to the keyslot.  Requests can be built from multiple bios, and the
+block layer must take the encryption context into account when trying to merge
+bios and requests.  For two bios/requests to be merged, they must have
+compatible encryption contexts: both unencrypted, or both encrypted with the
+same key and contiguous data unit numbers.  Only the encryption context for the
+first bio in a request is retained, since the remaining bios have been verified
+to be merge-compatible with the first bio.
+
+To make it possible for inline encryption to work with request_queue based
+layered devices, when a request is cloned, its encryption context is cloned as
+well.  When the cloned request is submitted, it is then processed as usual; this
+includes getting a keyslot from the clone's target device if needed.
+
+blk-crypto-fallback
+===================
+
+It is desirable for the inline encryption support of upper layers (e.g.
+filesystems) to be testable without real inline encryption hardware, and
+likewise for the block layer's keyslot management logic.  It is also desirable
+to allow upper layers to just always use inline encryption rather than
+implementing encryption in multiple ways.
+
+Therefore, we also introduce "blk-crypto-fallback", which is an implementation
+of inline encryption using the kernel crypto API.  blk-crypto-fallback is built
+into the block layer, so it works on any block device without any special setup.
+Essentially, when a bio with an encryption context is submitted to a
+request_queue that doesn't support that encryption context, the block layer will
+handle en/decryption of the bio using blk-crypto-fallback.
+
+For encryption, the data cannot be encrypted in-place, as callers usually rely
+on it being unmodified.  Instead, blk-crypto-fallback allocates bounce pages,
+fills a new bio with those bounce pages, encrypts the data into those bounce
+pages, and submits that "bounce" bio.  When the bounce bio completes,
+blk-crypto-fallback completes the original bio.  If the original bio is too
+large, multiple bounce bios may be required; see the code for details.
+
+For decryption, blk-crypto-fallback "wraps" the bio's completion callback
+(``bi_complete``) and private data (``bi_private``) with its own, unsets the
+bio's encryption context, then submits the bio.  If the read completes
+successfully, blk-crypto-fallback restores the bio's original completion
+callback and private data, then decrypts the bio's data in-place using the
+kernel crypto API.  Decryption happens from a workqueue, as it may sleep.
+Afterwards, blk-crypto-fallback completes the bio.
+
+In both cases, the bios that blk-crypto-fallback submits no longer have an
+encryption context.  Therefore, lower layers only see standard unencrypted I/O.
+
+blk-crypto-fallback also defines its own blk_crypto_profile and has its own
+"keyslots"; its keyslots contain ``struct crypto_skcipher`` objects.  The reason
+for this is twofold.  First, it allows the keyslot management logic to be tested
+without actual inline encryption hardware.  Second, similar to actual inline
+encryption hardware, the crypto API doesn't accept keys directly in requests but
+rather requires that they be set again of time, and setting keys can be
+expensive; moreover, allocating a crypto_skcipher can't happen on the I/O path
+at all due to the locks it takes.  Therefore, the concept of keyslots still
+makes sense for blk-crypto-fallback.
+
+Note that regardless of whether real inline encryption hardware or
 blk-crypto-fallback is used, the ciphertext written to disk (and hence the
 on-disk format of data) will be the same (assuming the hardware's implementation
 of the algorithm being used adheres to spec and functions correctly).
 
-If a ``request queue``'s inline encryption hardware claimed to support the
-encryption context specified with a bio, then it will not be handled by the
-``blk-crypto-fallback``. We will eventually reach a point in blk-mq when a
-struct request needs to be allocated for that bio. At that point,
-blk-mq tries to program the encryption context into the ``request_queue``'s
-keyslot_manager, and obtain a keyslot, which it stores in its newly added
-``keyslot`` field. This keyslot is released when the request is completed.
-
-When the first bio is added to a request, ``blk_crypto_rq_bio_prep`` is called,
-which sets the request's ``crypt_ctx`` to a copy of the bio's
-``bi_crypt_context``. bio_crypt_do_front_merge is called whenever a subsequent
-bio is merged to the front of the request, which updates the ``crypt_ctx`` of
-the request so that it matches the newly merged bio's ``bi_crypt_context``. In particular, the request keeps a copy of the ``bi_crypt_context`` of the first
-bio in its bio-list (blk-mq needs to be careful to maintain this invariant
-during bio and request merges).
-
-To make it possible for inline encryption to work with request queue based
-layered devices, when a request is cloned, its ``crypto fields`` are cloned as
-well. When the cloned request is submitted, blk-mq programs the
-``bi_crypt_context`` of the request into the clone's request_queue's keyslot
-manager, and stores the returned keyslot in the clone's ``keyslot``.
-
+blk-crypto-fallback is optional and is controlled by the
+``CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK`` kernel configuration option.
 
 API presented to users of the block layer
 =========================================
 
-``struct blk_crypto_key`` represents a crypto key (the raw key, size of the
-key, the crypto algorithm to use, the data unit size to use, and the number of
-bytes required to represent data unit numbers that will be specified with the
-``bi_crypt_context``).
-
-``blk_crypto_init_key`` allows upper layers to initialize such a
-``blk_crypto_key``.
-
-``bio_crypt_set_ctx`` should be called on any bio that a user of
-the block layer wants en/decrypted via inline encryption (or the
-blk-crypto-fallback, if hardware support isn't available for the desired
-crypto configuration). This function takes the ``blk_crypto_key`` and the
-data unit number (DUN) to use when en/decrypting the bio.
-
-``blk_crypto_config_supported`` allows upper layers to query whether or not the
-an encryption context passed to request queue can be handled by blk-crypto
-(either by real inline encryption hardware, or by the blk-crypto-fallback).
-This is useful e.g. when blk-crypto-fallback is disabled, and the upper layer
-wants to use an algorithm that may not supported by hardware - this function
-lets the upper layer know ahead of time that the algorithm isn't supported,
-and the upper layer can fallback to something else if appropriate.
-
-``blk_crypto_start_using_key`` - Upper layers must call this function on
-``blk_crypto_key`` and a ``request_queue`` before using the key with any bio
-headed for that ``request_queue``. This function ensures that either the
-hardware supports the key's crypto settings, or the crypto API fallback has
-transforms for the needed mode allocated and ready to go. Note that this
-function may allocate an ``skcipher``, and must not be called from the data
-path, since allocating ``skciphers`` from the data path can deadlock.
-
-``blk_crypto_evict_key`` *must* be called by upper layers before a
-``blk_crypto_key`` is freed. Further, it *must* only be called only once
-there are no more in-flight requests that use that ``blk_crypto_key``.
-``blk_crypto_evict_key`` will ensure that a key is removed from any keyslots in
-inline encryption hardware that the key might have been programmed into (or the blk-crypto-fallback).
+``blk_crypto_init_key()`` allows users to initialize a blk_crypto_key.
+
+``blk_crypto_config_supported()`` allows users to check ahead of time whether
+inline encryption with particular crypto settings will work on a particular
+request_queue -- either via hardware or via blk-crypto-fallback.  This function
+takes in a ``struct blk_crypto_config`` which is like blk_crypto_key, but omits
+the actual bytes of the key and instead just contains the algorithm, data unit
+size, etc.  This function can be useful if blk-crypto-fallback is disabled.
+
+Users must call ``blk_crypto_start_using_key()`` before actually starting to use
+a blk_crypto_key on a request_queue (even if ``blk_crypto_config_supported()``
+was called earlier).  This is needed to initialize blk-crypto-fallback if it
+will be needed.  This must not be called from the data path, as this may have to
+allocate resources, which may deadlock in that case.
+
+Next, to attach an encryption context to a bio, users should call
+``bio_crypt_set_ctx()``.  This function allocates a bio_crypt_ctx and attaches
+it to a bio, given the blk_crypto_key and the data unit number that will be used
+for en/decryption.  Users don't need to worry about freeing the bio_crypt_ctx
+later, as that happens automatically when the bio is freed or reset.
+
+Finally, when done using inline encryption with a blk_crypto_key on a
+request_queue, users must call ``blk_crypto_evict_key()``.  This ensures that
+the key is evicted from all keyslots it may be programmed into, and unlinked
+from any kernel data structures it may be linked into.
+
+In summary, for users of the block layer, the lifecycle of a blk_crypto_key is
+as follows:
+
+1. ``blk_crypto_config_supported()`` (optional)
+2. ``blk_crypto_init_key()``
+3. ``blk_crypto_start_using_key()``
+4. ``bio_crypt_set_ctx()`` (potentially many times)
+5. ``blk_crypto_evict_key()`` (after all I/O has completed)
+6. Zeroize the blk_crypto_key (this has no dedicated function)
+
+If a blk_crypto_key is being used on multiple request_queues, then
+``blk_crypto_config_supported()`` (if used), ``blk_crypto_start_using_key()``,
+and ``blk_crypto_evict_key()`` must be called on each request_queue.
 
 API presented to device drivers
 ===============================
 
-A :c:type:``struct blk_keyslot_manager`` should be set up by device drivers in
-the ``request_queue`` of the device. The device driver needs to call
-``blk_ksm_init`` (or its resource-managed variant ``devm_blk_ksm_init``) on the
-``blk_keyslot_manager``, while specifying the number of keyslots supported by
-the hardware.
-
-The device driver also needs to tell the KSM how to actually manipulate the
-IE hardware in the device to do things like programming the crypto key into
-the IE hardware into a particular keyslot. All this is achieved through the
-struct blk_ksm_ll_ops field in the KSM that the device driver
-must fill up after initing the ``blk_keyslot_manager``.
-
-The KSM also handles runtime power management for the device when applicable
-(e.g. when it wants to program a crypto key into the IE hardware, the device
-must be runtime powered on) - so the device driver must also set the ``dev``
-field in the ksm to point to the `struct device` for the KSM to use for runtime
-power management.
-
-``blk_ksm_reprogram_all_keys`` can be called by device drivers if the device
-needs each and every of its keyslots to be reprogrammed with the key it
-"should have" at the point in time when the function is called. This is useful
-e.g. if a device loses all its keys on runtime power down/up.
-
-If the driver used ``blk_ksm_init`` instead of ``devm_blk_ksm_init``, then
-``blk_ksm_destroy`` should be called to free up all resources used by a
-``blk_keyslot_manager`` once it is no longer needed.
+A device driver that wants to support inline encryption must set up a
+blk_crypto_profile in the request_queue of its device.  To do this, it first
+must call ``blk_crypto_profile_init()`` (or its resource-managed variant
+``devm_blk_crypto_profile_init()``), providing the number of keyslots.
+
+Next, it must advertise its crypto capabilities by setting fields in the
+blk_crypto_profile, e.g. ``modes_supported`` and ``max_dun_bytes_supported``.
+
+It then must set function pointers in the ``ll_ops`` field of the
+blk_crypto_profile to tell upper layers how to control the inline encryption
+hardware, e.g. how to program and evict keyslots.  Most drivers will need to
+implement ``keyslot_program`` and ``keyslot_evict``.  For details, see the
+comments for ``struct blk_crypto_ll_ops``.
+
+Once the driver registers a blk_crypto_profile with a request_queue, I/O
+requests the driver receives via that queue may have an encryption context.  All
+encryption contexts will be compatible with the crypto capabilities declared in
+the blk_crypto_profile, so drivers don't need to worry about handling
+unsupported requests.  Also, if a nonzero number of keyslots was declared in the
+blk_crypto_profile, then all I/O requests that have an encryption context will
+also have a keyslot which was already programmed with the appropriate key.
+
+If the driver implements runtime suspend and its blk_crypto_ll_ops don't work
+while the device is runtime-suspended, then the driver must also set the ``dev``
+field of the blk_crypto_profile to point to the ``struct device`` that will be
+resumed before any of the low-level operations are called.
+
+If there are situations where the inline encryption hardware loses the contents
+of its keyslots, e.g. device resets, the driver must handle reprogramming the
+keyslots.  To do this, the driver may call ``blk_crypto_reprogram_all_keys()``.
+
+Finally, if the driver used ``blk_crypto_profile_init()`` instead of
+``devm_blk_crypto_profile_init()``, then it is responsible for calling
+``blk_crypto_profile_destroy()`` when the crypto profile is no longer needed.
 
 Layered Devices
 ===============
 
-Request queue based layered devices like dm-rq that wish to support IE need to
-create their own keyslot manager for their request queue, and expose whatever
-functionality they choose. When a layered device wants to pass a clone of that
-request to another ``request_queue``, blk-crypto will initialize and prepare the
-clone as necessary - see ``blk_crypto_insert_cloned_request`` in
-``blk-crypto.c``.
-
-
-Future Optimizations for layered devices
-========================================
-
-Creating a keyslot manager for a layered device uses up memory for each
-keyslot, and in general, a layered device merely passes the request on to a
-"child" device, so the keyslots in the layered device itself are completely
-unused, and don't need any refcounting or keyslot programming. We can instead
-define a new type of KSM; the "passthrough KSM", that layered devices can use
-to advertise an unlimited number of keyslots, and support for any encryption
-algorithms they choose, while not actually using any memory for each keyslot.
-Another use case for the "passthrough KSM" is for IE devices that do not have a
-limited number of keyslots.
-
+Request queue based layered devices like dm-rq that wish to support inline
+encryption need to create their own blk_crypto_profile for their request_queue,
+and expose whatever functionality they choose. When a layered device wants to
+pass a clone of that request to another request_queue, blk-crypto will
+initialize and prepare the clone as necessary; see
+``blk_crypto_insert_cloned_request()``.
 
 Interaction between inline encryption and blk integrity
 =======================================================
@@ -257,7 +290,7 @@ Because there isn't any real hardware yet, it seems prudent to assume that
 hardware implementations might not implement both features together correctly,
 and disallow the combination for now. Whenever a device supports integrity, the
 kernel will pretend that the device does not support hardware inline encryption
-(by essentially setting the keyslot manager in the request_queue of the device
-to NULL). When the crypto API fallback is enabled, this means that all bios with
-and encryption context will use the fallback, and IO will complete as usual.
-When the fallback is disabled, a bio with an encryption context will be failed.
+(by setting the blk_crypto_profile in the request_queue of the device to NULL).
+When the crypto API fallback is enabled, this means that all bios with and
+encryption context will use the fallback, and IO will complete as usual.  When
+the fallback is disabled, a bio with an encryption context will be failed.
Signature · 6 lines
2.33.0

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