xref: /linux/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c (revision a3f9e4bc1ec9d8f1e352eb7c1cbaea3168246be7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2  /* Algorithms supported by virtio crypto device
3   *
4   * Authors: Gonglei <arei.gonglei@huawei.com>
5   *
6   * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
7   */
8 
9 #include <crypto/engine.h>
10 #include <crypto/internal/skcipher.h>
11 #include <crypto/scatterwalk.h>
12 #include <linux/err.h>
13 #include <linux/scatterlist.h>
14 #include <uapi/linux/virtio_crypto.h>
15 #include "virtio_crypto_common.h"
16 
17 
18 struct virtio_crypto_skcipher_ctx {
19 	struct virtio_crypto *vcrypto;
20 	struct crypto_skcipher *tfm;
21 
22 	struct virtio_crypto_sym_session_info enc_sess_info;
23 	struct virtio_crypto_sym_session_info dec_sess_info;
24 };
25 
26 struct virtio_crypto_sym_request {
27 	struct virtio_crypto_request base;
28 
29 	/* Cipher or aead */
30 	uint32_t type;
31 	struct virtio_crypto_skcipher_ctx *skcipher_ctx;
32 	struct skcipher_request *skcipher_req;
33 	uint8_t *iv;
34 	/* Encryption? */
35 	bool encrypt;
36 };
37 
38 struct virtio_crypto_algo {
39 	uint32_t algonum;
40 	uint32_t service;
41 	unsigned int active_devs;
42 	struct skcipher_engine_alg algo;
43 };
44 
45 /*
46  * The algs_lock protects the below global virtio_crypto_active_devs
47  * and crypto algorithms registion.
48  */
49 static DEFINE_MUTEX(algs_lock);
50 static void virtio_crypto_skcipher_finalize_req(
51 	struct virtio_crypto_sym_request *vc_sym_req,
52 	struct skcipher_request *req,
53 	int err);
54 
55 static void virtio_crypto_dataq_sym_callback
56 		(struct virtio_crypto_request *vc_req, int len)
57 {
58 	struct virtio_crypto_sym_request *vc_sym_req =
59 		container_of(vc_req, struct virtio_crypto_sym_request, base);
60 	struct skcipher_request *ablk_req;
61 	int error;
62 
63 	/* Finish the encrypt or decrypt process */
64 	if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
65 		switch (vc_req->status) {
66 		case VIRTIO_CRYPTO_OK:
67 			error = 0;
68 			break;
69 		case VIRTIO_CRYPTO_INVSESS:
70 		case VIRTIO_CRYPTO_ERR:
71 			error = -EINVAL;
72 			break;
73 		case VIRTIO_CRYPTO_BADMSG:
74 			error = -EBADMSG;
75 			break;
76 		default:
77 			error = -EIO;
78 			break;
79 		}
80 		ablk_req = vc_sym_req->skcipher_req;
81 		virtio_crypto_skcipher_finalize_req(vc_sym_req,
82 							ablk_req, error);
83 	}
84 }
85 
86 static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
87 {
88 	u64 total = 0;
89 
90 	for (total = 0; sg; sg = sg_next(sg))
91 		total += sg->length;
92 
93 	return total;
94 }
95 
96 static int
97 virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
98 {
99 	switch (key_len) {
100 	case AES_KEYSIZE_128:
101 	case AES_KEYSIZE_192:
102 	case AES_KEYSIZE_256:
103 		*alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
104 		break;
105 	default:
106 		return -EINVAL;
107 	}
108 	return 0;
109 }
110 
111 static int virtio_crypto_alg_skcipher_init_session(
112 		struct virtio_crypto_skcipher_ctx *ctx,
113 		uint32_t alg, const uint8_t *key,
114 		unsigned int keylen,
115 		int encrypt)
116 {
117 	struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
118 	struct virtio_crypto *vcrypto = ctx->vcrypto;
119 	int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
120 	int err;
121 	unsigned int num_out = 0, num_in = 0;
122 	struct virtio_crypto_op_ctrl_req *ctrl;
123 	struct virtio_crypto_session_input *input;
124 	struct virtio_crypto_sym_create_session_req *sym_create_session;
125 	struct virtio_crypto_ctrl_request *vc_ctrl_req;
126 
127 	/*
128 	 * Avoid to do DMA from the stack, switch to using
129 	 * dynamically-allocated for the key
130 	 */
131 	uint8_t *cipher_key = kmemdup(key, keylen, GFP_ATOMIC);
132 
133 	if (!cipher_key)
134 		return -ENOMEM;
135 
136 	vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL);
137 	if (!vc_ctrl_req) {
138 		err = -ENOMEM;
139 		goto out;
140 	}
141 
142 	/* Pad ctrl header */
143 	ctrl = &vc_ctrl_req->ctrl;
144 	ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
145 	ctrl->header.algo = cpu_to_le32(alg);
146 	/* Set the default dataqueue id to 0 */
147 	ctrl->header.queue_id = 0;
148 
149 	input = &vc_ctrl_req->input;
150 	input->status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
151 	/* Pad cipher's parameters */
152 	sym_create_session = &ctrl->u.sym_create_session;
153 	sym_create_session->op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
154 	sym_create_session->u.cipher.para.algo = ctrl->header.algo;
155 	sym_create_session->u.cipher.para.keylen = cpu_to_le32(keylen);
156 	sym_create_session->u.cipher.para.op = cpu_to_le32(op);
157 
158 	sg_init_one(&outhdr, ctrl, sizeof(*ctrl));
159 	sgs[num_out++] = &outhdr;
160 
161 	/* Set key */
162 	sg_init_one(&key_sg, cipher_key, keylen);
163 	sgs[num_out++] = &key_sg;
164 
165 	/* Return status and session id back */
166 	sg_init_one(&inhdr, input, sizeof(*input));
167 	sgs[num_out + num_in++] = &inhdr;
168 
169 	err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req);
170 	if (err < 0)
171 		goto out;
172 
173 	if (le32_to_cpu(input->status) != VIRTIO_CRYPTO_OK) {
174 		pr_err("virtio_crypto: Create session failed status: %u\n",
175 			le32_to_cpu(input->status));
176 		err = -EINVAL;
177 		goto out;
178 	}
179 
180 	if (encrypt)
181 		ctx->enc_sess_info.session_id = le64_to_cpu(input->session_id);
182 	else
183 		ctx->dec_sess_info.session_id = le64_to_cpu(input->session_id);
184 
185 	err = 0;
186 out:
187 	kfree(vc_ctrl_req);
188 	kfree_sensitive(cipher_key);
189 	return err;
190 }
191 
192 static int virtio_crypto_alg_skcipher_close_session(
193 		struct virtio_crypto_skcipher_ctx *ctx,
194 		int encrypt)
195 {
196 	struct scatterlist outhdr, status_sg, *sgs[2];
197 	struct virtio_crypto_destroy_session_req *destroy_session;
198 	struct virtio_crypto *vcrypto = ctx->vcrypto;
199 	int err;
200 	unsigned int num_out = 0, num_in = 0;
201 	struct virtio_crypto_op_ctrl_req *ctrl;
202 	struct virtio_crypto_inhdr *ctrl_status;
203 	struct virtio_crypto_ctrl_request *vc_ctrl_req;
204 
205 	vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL);
206 	if (!vc_ctrl_req)
207 		return -ENOMEM;
208 
209 	ctrl_status = &vc_ctrl_req->ctrl_status;
210 	ctrl_status->status = VIRTIO_CRYPTO_ERR;
211 	/* Pad ctrl header */
212 	ctrl = &vc_ctrl_req->ctrl;
213 	ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
214 	/* Set the default virtqueue id to 0 */
215 	ctrl->header.queue_id = 0;
216 
217 	destroy_session = &ctrl->u.destroy_session;
218 
219 	if (encrypt)
220 		destroy_session->session_id = cpu_to_le64(ctx->enc_sess_info.session_id);
221 	else
222 		destroy_session->session_id = cpu_to_le64(ctx->dec_sess_info.session_id);
223 
224 	sg_init_one(&outhdr, ctrl, sizeof(*ctrl));
225 	sgs[num_out++] = &outhdr;
226 
227 	/* Return status and session id back */
228 	sg_init_one(&status_sg, &ctrl_status->status, sizeof(ctrl_status->status));
229 	sgs[num_out + num_in++] = &status_sg;
230 
231 	err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req);
232 	if (err < 0)
233 		goto out;
234 
235 	if (ctrl_status->status != VIRTIO_CRYPTO_OK) {
236 		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
237 			ctrl_status->status, destroy_session->session_id);
238 
239 		err = -EINVAL;
240 		goto out;
241 	}
242 
243 	err = 0;
244 out:
245 	kfree(vc_ctrl_req);
246 	return err;
247 }
248 
249 static int virtio_crypto_alg_skcipher_init_sessions(
250 		struct virtio_crypto_skcipher_ctx *ctx,
251 		const uint8_t *key, unsigned int keylen)
252 {
253 	uint32_t alg;
254 	int ret;
255 	struct virtio_crypto *vcrypto = ctx->vcrypto;
256 
257 	if (keylen > vcrypto->max_cipher_key_len) {
258 		pr_err("virtio_crypto: the key is too long\n");
259 		return -EINVAL;
260 	}
261 
262 	if (virtio_crypto_alg_validate_key(keylen, &alg))
263 		return -EINVAL;
264 
265 	/* Create encryption session */
266 	ret = virtio_crypto_alg_skcipher_init_session(ctx,
267 			alg, key, keylen, 1);
268 	if (ret)
269 		return ret;
270 	/* Create decryption session */
271 	ret = virtio_crypto_alg_skcipher_init_session(ctx,
272 			alg, key, keylen, 0);
273 	if (ret) {
274 		virtio_crypto_alg_skcipher_close_session(ctx, 1);
275 		return ret;
276 	}
277 	return 0;
278 }
279 
280 /* Note: kernel crypto API realization */
281 static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm,
282 					 const uint8_t *key,
283 					 unsigned int keylen)
284 {
285 	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
286 	uint32_t alg;
287 	int ret;
288 
289 	ret = virtio_crypto_alg_validate_key(keylen, &alg);
290 	if (ret)
291 		return ret;
292 
293 	if (!ctx->vcrypto) {
294 		/* New key */
295 		int node = virtio_crypto_get_current_node();
296 		struct virtio_crypto *vcrypto =
297 				      virtcrypto_get_dev_node(node,
298 				      VIRTIO_CRYPTO_SERVICE_CIPHER, alg);
299 		if (!vcrypto) {
300 			pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n");
301 			return -ENODEV;
302 		}
303 
304 		ctx->vcrypto = vcrypto;
305 	} else {
306 		/* Rekeying, we should close the created sessions previously */
307 		virtio_crypto_alg_skcipher_close_session(ctx, 1);
308 		virtio_crypto_alg_skcipher_close_session(ctx, 0);
309 	}
310 
311 	ret = virtio_crypto_alg_skcipher_init_sessions(ctx, key, keylen);
312 	if (ret) {
313 		virtcrypto_dev_put(ctx->vcrypto);
314 		ctx->vcrypto = NULL;
315 
316 		return ret;
317 	}
318 
319 	return 0;
320 }
321 
322 static int
323 __virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
324 		struct skcipher_request *req,
325 		struct data_queue *data_vq)
326 {
327 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
328 	struct virtio_crypto_skcipher_ctx *ctx = vc_sym_req->skcipher_ctx;
329 	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
330 	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
331 	struct virtio_crypto *vcrypto = ctx->vcrypto;
332 	struct virtio_crypto_op_data_req *req_data;
333 	int src_nents, dst_nents;
334 	int err;
335 	unsigned long flags;
336 	struct scatterlist outhdr, iv_sg, status_sg, **sgs;
337 	u64 dst_len;
338 	unsigned int num_out = 0, num_in = 0;
339 	int sg_total;
340 	uint8_t *iv;
341 	struct scatterlist *sg;
342 
343 	src_nents = sg_nents_for_len(req->src, req->cryptlen);
344 	if (src_nents < 0) {
345 		pr_err("Invalid number of src SG.\n");
346 		return src_nents;
347 	}
348 
349 	dst_nents = sg_nents(req->dst);
350 
351 	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
352 			src_nents, dst_nents);
353 
354 	/* Why 3?  outhdr + iv + inhdr */
355 	sg_total = src_nents + dst_nents + 3;
356 	sgs = kcalloc_node(sg_total, sizeof(*sgs), GFP_KERNEL,
357 				dev_to_node(&vcrypto->vdev->dev));
358 	if (!sgs)
359 		return -ENOMEM;
360 
361 	req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL,
362 				dev_to_node(&vcrypto->vdev->dev));
363 	if (!req_data) {
364 		kfree(sgs);
365 		return -ENOMEM;
366 	}
367 
368 	vc_req->req_data = req_data;
369 	vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
370 	/* Head of operation */
371 	if (vc_sym_req->encrypt) {
372 		req_data->header.session_id =
373 			cpu_to_le64(ctx->enc_sess_info.session_id);
374 		req_data->header.opcode =
375 			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
376 	} else {
377 		req_data->header.session_id =
378 			cpu_to_le64(ctx->dec_sess_info.session_id);
379 		req_data->header.opcode =
380 			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
381 	}
382 	req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
383 	req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
384 	req_data->u.sym_req.u.cipher.para.src_data_len =
385 			cpu_to_le32(req->cryptlen);
386 
387 	dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
388 	if (unlikely(dst_len > U32_MAX)) {
389 		pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
390 		err = -EINVAL;
391 		goto free;
392 	}
393 
394 	dst_len = min_t(unsigned int, req->cryptlen, dst_len);
395 	pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
396 			req->cryptlen, dst_len);
397 
398 	if (unlikely(req->cryptlen + dst_len + ivsize +
399 		sizeof(vc_req->status) > vcrypto->max_size)) {
400 		pr_err("virtio_crypto: The length is too big\n");
401 		err = -EINVAL;
402 		goto free;
403 	}
404 
405 	req_data->u.sym_req.u.cipher.para.dst_data_len =
406 			cpu_to_le32((uint32_t)dst_len);
407 
408 	/* Outhdr */
409 	sg_init_one(&outhdr, req_data, sizeof(*req_data));
410 	sgs[num_out++] = &outhdr;
411 
412 	/* IV */
413 
414 	/*
415 	 * Avoid to do DMA from the stack, switch to using
416 	 * dynamically-allocated for the IV
417 	 */
418 	iv = kzalloc_node(ivsize, GFP_ATOMIC,
419 				dev_to_node(&vcrypto->vdev->dev));
420 	if (!iv) {
421 		err = -ENOMEM;
422 		goto free;
423 	}
424 	memcpy(iv, req->iv, ivsize);
425 	if (!vc_sym_req->encrypt)
426 		scatterwalk_map_and_copy(req->iv, req->src,
427 					 req->cryptlen - AES_BLOCK_SIZE,
428 					 AES_BLOCK_SIZE, 0);
429 
430 	sg_init_one(&iv_sg, iv, ivsize);
431 	sgs[num_out++] = &iv_sg;
432 	vc_sym_req->iv = iv;
433 
434 	/* Source data */
435 	for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
436 		sgs[num_out++] = sg;
437 
438 	/* Destination data */
439 	for (sg = req->dst; sg; sg = sg_next(sg))
440 		sgs[num_out + num_in++] = sg;
441 
442 	/* Status */
443 	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
444 	sgs[num_out + num_in++] = &status_sg;
445 
446 	vc_req->sgs = sgs;
447 
448 	spin_lock_irqsave(&data_vq->lock, flags);
449 	err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
450 				num_in, vc_req, GFP_ATOMIC);
451 	virtqueue_kick(data_vq->vq);
452 	spin_unlock_irqrestore(&data_vq->lock, flags);
453 	if (unlikely(err < 0))
454 		goto free_iv;
455 
456 	return 0;
457 
458 free_iv:
459 	kfree_sensitive(iv);
460 free:
461 	kfree_sensitive(req_data);
462 	kfree(sgs);
463 	return err;
464 }
465 
466 static int virtio_crypto_skcipher_encrypt(struct skcipher_request *req)
467 {
468 	struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
469 	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm);
470 	struct virtio_crypto_sym_request *vc_sym_req =
471 				skcipher_request_ctx(req);
472 	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
473 	struct virtio_crypto *vcrypto = ctx->vcrypto;
474 	/* Use the first data virtqueue as default */
475 	struct data_queue *data_vq = &vcrypto->data_vq[0];
476 
477 	if (!req->cryptlen)
478 		return 0;
479 	if (req->cryptlen % AES_BLOCK_SIZE)
480 		return -EINVAL;
481 
482 	vc_req->dataq = data_vq;
483 	vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
484 	vc_sym_req->skcipher_ctx = ctx;
485 	vc_sym_req->skcipher_req = req;
486 	vc_sym_req->encrypt = true;
487 
488 	return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req);
489 }
490 
491 static int virtio_crypto_skcipher_decrypt(struct skcipher_request *req)
492 {
493 	struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
494 	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm);
495 	struct virtio_crypto_sym_request *vc_sym_req =
496 				skcipher_request_ctx(req);
497 	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
498 	struct virtio_crypto *vcrypto = ctx->vcrypto;
499 	/* Use the first data virtqueue as default */
500 	struct data_queue *data_vq = &vcrypto->data_vq[0];
501 
502 	if (!req->cryptlen)
503 		return 0;
504 	if (req->cryptlen % AES_BLOCK_SIZE)
505 		return -EINVAL;
506 
507 	vc_req->dataq = data_vq;
508 	vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
509 	vc_sym_req->skcipher_ctx = ctx;
510 	vc_sym_req->skcipher_req = req;
511 	vc_sym_req->encrypt = false;
512 
513 	return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req);
514 }
515 
516 static int virtio_crypto_skcipher_init(struct crypto_skcipher *tfm)
517 {
518 	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
519 
520 	crypto_skcipher_set_reqsize(tfm, sizeof(struct virtio_crypto_sym_request));
521 	ctx->tfm = tfm;
522 
523 	return 0;
524 }
525 
526 static void virtio_crypto_skcipher_exit(struct crypto_skcipher *tfm)
527 {
528 	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
529 
530 	if (!ctx->vcrypto)
531 		return;
532 
533 	virtio_crypto_alg_skcipher_close_session(ctx, 1);
534 	virtio_crypto_alg_skcipher_close_session(ctx, 0);
535 	virtcrypto_dev_put(ctx->vcrypto);
536 	ctx->vcrypto = NULL;
537 }
538 
539 int virtio_crypto_skcipher_crypt_req(
540 	struct crypto_engine *engine, void *vreq)
541 {
542 	struct skcipher_request *req = container_of(vreq, struct skcipher_request, base);
543 	struct virtio_crypto_sym_request *vc_sym_req =
544 				skcipher_request_ctx(req);
545 	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
546 	struct data_queue *data_vq = vc_req->dataq;
547 	int ret;
548 
549 	ret = __virtio_crypto_skcipher_do_req(vc_sym_req, req, data_vq);
550 	if (ret < 0)
551 		return ret;
552 
553 	virtqueue_kick(data_vq->vq);
554 
555 	return 0;
556 }
557 
558 static void virtio_crypto_skcipher_finalize_req(
559 	struct virtio_crypto_sym_request *vc_sym_req,
560 	struct skcipher_request *req,
561 	int err)
562 {
563 	if (vc_sym_req->encrypt)
564 		scatterwalk_map_and_copy(req->iv, req->dst,
565 					 req->cryptlen - AES_BLOCK_SIZE,
566 					 AES_BLOCK_SIZE, 0);
567 	kfree_sensitive(vc_sym_req->iv);
568 	virtcrypto_clear_request(&vc_sym_req->base);
569 
570 	crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
571 					   req, err);
572 }
573 
574 static struct virtio_crypto_algo virtio_crypto_algs[] = { {
575 	.algonum = VIRTIO_CRYPTO_CIPHER_AES_CBC,
576 	.service = VIRTIO_CRYPTO_SERVICE_CIPHER,
577 	.algo.base = {
578 		.base.cra_name		= "cbc(aes)",
579 		.base.cra_driver_name	= "virtio_crypto_aes_cbc",
580 		.base.cra_priority	= 150,
581 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
582 					  CRYPTO_ALG_ALLOCATES_MEMORY,
583 		.base.cra_blocksize	= AES_BLOCK_SIZE,
584 		.base.cra_ctxsize	= sizeof(struct virtio_crypto_skcipher_ctx),
585 		.base.cra_module	= THIS_MODULE,
586 		.init			= virtio_crypto_skcipher_init,
587 		.exit			= virtio_crypto_skcipher_exit,
588 		.setkey			= virtio_crypto_skcipher_setkey,
589 		.decrypt		= virtio_crypto_skcipher_decrypt,
590 		.encrypt		= virtio_crypto_skcipher_encrypt,
591 		.min_keysize		= AES_MIN_KEY_SIZE,
592 		.max_keysize		= AES_MAX_KEY_SIZE,
593 		.ivsize			= AES_BLOCK_SIZE,
594 	},
595 	.algo.op = {
596 		.do_one_request = virtio_crypto_skcipher_crypt_req,
597 	},
598 } };
599 
600 int virtio_crypto_skcipher_algs_register(struct virtio_crypto *vcrypto)
601 {
602 	int ret = 0;
603 	int i = 0;
604 
605 	mutex_lock(&algs_lock);
606 
607 	for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
608 
609 		uint32_t service = virtio_crypto_algs[i].service;
610 		uint32_t algonum = virtio_crypto_algs[i].algonum;
611 
612 		if (!virtcrypto_algo_is_supported(vcrypto, service, algonum))
613 			continue;
614 
615 		if (virtio_crypto_algs[i].active_devs == 0) {
616 			ret = crypto_engine_register_skcipher(&virtio_crypto_algs[i].algo);
617 			if (ret)
618 				goto unlock;
619 		}
620 
621 		virtio_crypto_algs[i].active_devs++;
622 		dev_info(&vcrypto->vdev->dev, "Registered algo %s\n",
623 			 virtio_crypto_algs[i].algo.base.base.cra_name);
624 	}
625 
626 unlock:
627 	mutex_unlock(&algs_lock);
628 	return ret;
629 }
630 
631 void virtio_crypto_skcipher_algs_unregister(struct virtio_crypto *vcrypto)
632 {
633 	int i = 0;
634 
635 	mutex_lock(&algs_lock);
636 
637 	for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
638 
639 		uint32_t service = virtio_crypto_algs[i].service;
640 		uint32_t algonum = virtio_crypto_algs[i].algonum;
641 
642 		if (virtio_crypto_algs[i].active_devs == 0 ||
643 		    !virtcrypto_algo_is_supported(vcrypto, service, algonum))
644 			continue;
645 
646 		if (virtio_crypto_algs[i].active_devs == 1)
647 			crypto_engine_unregister_skcipher(&virtio_crypto_algs[i].algo);
648 
649 		virtio_crypto_algs[i].active_devs--;
650 	}
651 
652 	mutex_unlock(&algs_lock);
653 }
654