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 <linux/scatterlist.h>
10#include <crypto/algapi.h>
11#include <crypto/internal/skcipher.h>
12#include <linux/err.h>
13#include <crypto/scatterwalk.h>
14#include <linux/atomic.h>
15
16#include <uapi/linux/virtio_crypto.h>
17#include "virtio_crypto_common.h"
18
19
20struct virtio_crypto_skcipher_ctx {
21	struct crypto_engine_ctx enginectx;
22	struct virtio_crypto *vcrypto;
23	struct crypto_skcipher *tfm;
24
25	struct virtio_crypto_sym_session_info enc_sess_info;
26	struct virtio_crypto_sym_session_info dec_sess_info;
27};
28
29struct virtio_crypto_sym_request {
30	struct virtio_crypto_request base;
31
32	/* Cipher or aead */
33	uint32_t type;
34	struct virtio_crypto_skcipher_ctx *skcipher_ctx;
35	struct skcipher_request *skcipher_req;
36	uint8_t *iv;
37	/* Encryption? */
38	bool encrypt;
39};
40
41struct virtio_crypto_algo {
42	uint32_t algonum;
43	uint32_t service;
44	unsigned int active_devs;
45	struct skcipher_alg algo;
46};
47
48/*
49 * The algs_lock protects the below global virtio_crypto_active_devs
50 * and crypto algorithms registion.
51 */
52static DEFINE_MUTEX(algs_lock);
53static void virtio_crypto_skcipher_finalize_req(
54	struct virtio_crypto_sym_request *vc_sym_req,
55	struct skcipher_request *req,
56	int err);
57
58static void virtio_crypto_dataq_sym_callback
59		(struct virtio_crypto_request *vc_req, int len)
60{
61	struct virtio_crypto_sym_request *vc_sym_req =
62		container_of(vc_req, struct virtio_crypto_sym_request, base);
63	struct skcipher_request *ablk_req;
64	int error;
65
66	/* Finish the encrypt or decrypt process */
67	if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
68		switch (vc_req->status) {
69		case VIRTIO_CRYPTO_OK:
70			error = 0;
71			break;
72		case VIRTIO_CRYPTO_INVSESS:
73		case VIRTIO_CRYPTO_ERR:
74			error = -EINVAL;
75			break;
76		case VIRTIO_CRYPTO_BADMSG:
77			error = -EBADMSG;
78			break;
79		default:
80			error = -EIO;
81			break;
82		}
83		ablk_req = vc_sym_req->skcipher_req;
84		virtio_crypto_skcipher_finalize_req(vc_sym_req,
85							ablk_req, error);
86	}
87}
88
89static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
90{
91	u64 total = 0;
92
93	for (total = 0; sg; sg = sg_next(sg))
94		total += sg->length;
95
96	return total;
97}
98
99static int
100virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
101{
102	switch (key_len) {
103	case AES_KEYSIZE_128:
104	case AES_KEYSIZE_192:
105	case AES_KEYSIZE_256:
106		*alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
107		break;
108	default:
109		return -EINVAL;
110	}
111	return 0;
112}
113
114static int virtio_crypto_alg_skcipher_init_session(
115		struct virtio_crypto_skcipher_ctx *ctx,
116		uint32_t alg, const uint8_t *key,
117		unsigned int keylen,
118		int encrypt)
119{
120	struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
121	struct virtio_crypto *vcrypto = ctx->vcrypto;
122	int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
123	int err;
124	unsigned int num_out = 0, num_in = 0;
125	struct virtio_crypto_op_ctrl_req *ctrl;
126	struct virtio_crypto_session_input *input;
127	struct virtio_crypto_sym_create_session_req *sym_create_session;
128	struct virtio_crypto_ctrl_request *vc_ctrl_req;
129
130	/*
131	 * Avoid to do DMA from the stack, switch to using
132	 * dynamically-allocated for the key
133	 */
134	uint8_t *cipher_key = kmemdup(key, keylen, GFP_ATOMIC);
135
136	if (!cipher_key)
137		return -ENOMEM;
138
139	vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL);
140	if (!vc_ctrl_req) {
141		err = -ENOMEM;
142		goto out;
143	}
144
145	/* Pad ctrl header */
146	ctrl = &vc_ctrl_req->ctrl;
147	ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
148	ctrl->header.algo = cpu_to_le32(alg);
149	/* Set the default dataqueue id to 0 */
150	ctrl->header.queue_id = 0;
151
152	input = &vc_ctrl_req->input;
153	input->status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
154	/* Pad cipher's parameters */
155	sym_create_session = &ctrl->u.sym_create_session;
156	sym_create_session->op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
157	sym_create_session->u.cipher.para.algo = ctrl->header.algo;
158	sym_create_session->u.cipher.para.keylen = cpu_to_le32(keylen);
159	sym_create_session->u.cipher.para.op = cpu_to_le32(op);
160
161	sg_init_one(&outhdr, ctrl, sizeof(*ctrl));
162	sgs[num_out++] = &outhdr;
163
164	/* Set key */
165	sg_init_one(&key_sg, cipher_key, keylen);
166	sgs[num_out++] = &key_sg;
167
168	/* Return status and session id back */
169	sg_init_one(&inhdr, input, sizeof(*input));
170	sgs[num_out + num_in++] = &inhdr;
171
172	err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req);
173	if (err < 0)
174		goto out;
175
176	if (le32_to_cpu(input->status) != VIRTIO_CRYPTO_OK) {
177		pr_err("virtio_crypto: Create session failed status: %u\n",
178			le32_to_cpu(input->status));
179		err = -EINVAL;
180		goto out;
181	}
182
183	if (encrypt)
184		ctx->enc_sess_info.session_id = le64_to_cpu(input->session_id);
185	else
186		ctx->dec_sess_info.session_id = le64_to_cpu(input->session_id);
187
188	err = 0;
189out:
190	kfree(vc_ctrl_req);
191	kfree_sensitive(cipher_key);
192	return err;
193}
194
195static int virtio_crypto_alg_skcipher_close_session(
196		struct virtio_crypto_skcipher_ctx *ctx,
197		int encrypt)
198{
199	struct scatterlist outhdr, status_sg, *sgs[2];
200	struct virtio_crypto_destroy_session_req *destroy_session;
201	struct virtio_crypto *vcrypto = ctx->vcrypto;
202	int err;
203	unsigned int num_out = 0, num_in = 0;
204	struct virtio_crypto_op_ctrl_req *ctrl;
205	struct virtio_crypto_inhdr *ctrl_status;
206	struct virtio_crypto_ctrl_request *vc_ctrl_req;
207
208	vc_ctrl_req = kzalloc(sizeof(*vc_ctrl_req), GFP_KERNEL);
209	if (!vc_ctrl_req)
210		return -ENOMEM;
211
212	ctrl_status = &vc_ctrl_req->ctrl_status;
213	ctrl_status->status = VIRTIO_CRYPTO_ERR;
214	/* Pad ctrl header */
215	ctrl = &vc_ctrl_req->ctrl;
216	ctrl->header.opcode = cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
217	/* Set the default virtqueue id to 0 */
218	ctrl->header.queue_id = 0;
219
220	destroy_session = &ctrl->u.destroy_session;
221
222	if (encrypt)
223		destroy_session->session_id = cpu_to_le64(ctx->enc_sess_info.session_id);
224	else
225		destroy_session->session_id = cpu_to_le64(ctx->dec_sess_info.session_id);
226
227	sg_init_one(&outhdr, ctrl, sizeof(*ctrl));
228	sgs[num_out++] = &outhdr;
229
230	/* Return status and session id back */
231	sg_init_one(&status_sg, &ctrl_status->status, sizeof(ctrl_status->status));
232	sgs[num_out + num_in++] = &status_sg;
233
234	err = virtio_crypto_ctrl_vq_request(vcrypto, sgs, num_out, num_in, vc_ctrl_req);
235	if (err < 0)
236		goto out;
237
238	if (ctrl_status->status != VIRTIO_CRYPTO_OK) {
239		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
240			ctrl_status->status, destroy_session->session_id);
241
242		err = -EINVAL;
243		goto out;
244	}
245
246	err = 0;
247out:
248	kfree(vc_ctrl_req);
249	return err;
250}
251
252static int virtio_crypto_alg_skcipher_init_sessions(
253		struct virtio_crypto_skcipher_ctx *ctx,
254		const uint8_t *key, unsigned int keylen)
255{
256	uint32_t alg;
257	int ret;
258	struct virtio_crypto *vcrypto = ctx->vcrypto;
259
260	if (keylen > vcrypto->max_cipher_key_len) {
261		pr_err("virtio_crypto: the key is too long\n");
262		return -EINVAL;
263	}
264
265	if (virtio_crypto_alg_validate_key(keylen, &alg))
266		return -EINVAL;
267
268	/* Create encryption session */
269	ret = virtio_crypto_alg_skcipher_init_session(ctx,
270			alg, key, keylen, 1);
271	if (ret)
272		return ret;
273	/* Create decryption session */
274	ret = virtio_crypto_alg_skcipher_init_session(ctx,
275			alg, key, keylen, 0);
276	if (ret) {
277		virtio_crypto_alg_skcipher_close_session(ctx, 1);
278		return ret;
279	}
280	return 0;
281}
282
283/* Note: kernel crypto API realization */
284static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm,
285					 const uint8_t *key,
286					 unsigned int keylen)
287{
288	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
289	uint32_t alg;
290	int ret;
291
292	ret = virtio_crypto_alg_validate_key(keylen, &alg);
293	if (ret)
294		return ret;
295
296	if (!ctx->vcrypto) {
297		/* New key */
298		int node = virtio_crypto_get_current_node();
299		struct virtio_crypto *vcrypto =
300				      virtcrypto_get_dev_node(node,
301				      VIRTIO_CRYPTO_SERVICE_CIPHER, alg);
302		if (!vcrypto) {
303			pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n");
304			return -ENODEV;
305		}
306
307		ctx->vcrypto = vcrypto;
308	} else {
309		/* Rekeying, we should close the created sessions previously */
310		virtio_crypto_alg_skcipher_close_session(ctx, 1);
311		virtio_crypto_alg_skcipher_close_session(ctx, 0);
312	}
313
314	ret = virtio_crypto_alg_skcipher_init_sessions(ctx, key, keylen);
315	if (ret) {
316		virtcrypto_dev_put(ctx->vcrypto);
317		ctx->vcrypto = NULL;
318
319		return ret;
320	}
321
322	return 0;
323}
324
325static int
326__virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
327		struct skcipher_request *req,
328		struct data_queue *data_vq)
329{
330	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
331	struct virtio_crypto_skcipher_ctx *ctx = vc_sym_req->skcipher_ctx;
332	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
333	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
334	struct virtio_crypto *vcrypto = ctx->vcrypto;
335	struct virtio_crypto_op_data_req *req_data;
336	int src_nents, dst_nents;
337	int err;
338	unsigned long flags;
339	struct scatterlist outhdr, iv_sg, status_sg, **sgs;
340	u64 dst_len;
341	unsigned int num_out = 0, num_in = 0;
342	int sg_total;
343	uint8_t *iv;
344	struct scatterlist *sg;
345
346	src_nents = sg_nents_for_len(req->src, req->cryptlen);
347	if (src_nents < 0) {
348		pr_err("Invalid number of src SG.\n");
349		return src_nents;
350	}
351
352	dst_nents = sg_nents(req->dst);
353
354	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
355			src_nents, dst_nents);
356
357	/* Why 3?  outhdr + iv + inhdr */
358	sg_total = src_nents + dst_nents + 3;
359	sgs = kcalloc_node(sg_total, sizeof(*sgs), GFP_KERNEL,
360				dev_to_node(&vcrypto->vdev->dev));
361	if (!sgs)
362		return -ENOMEM;
363
364	req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL,
365				dev_to_node(&vcrypto->vdev->dev));
366	if (!req_data) {
367		kfree(sgs);
368		return -ENOMEM;
369	}
370
371	vc_req->req_data = req_data;
372	vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
373	/* Head of operation */
374	if (vc_sym_req->encrypt) {
375		req_data->header.session_id =
376			cpu_to_le64(ctx->enc_sess_info.session_id);
377		req_data->header.opcode =
378			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
379	} else {
380		req_data->header.session_id =
381			cpu_to_le64(ctx->dec_sess_info.session_id);
382		req_data->header.opcode =
383			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
384	}
385	req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
386	req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
387	req_data->u.sym_req.u.cipher.para.src_data_len =
388			cpu_to_le32(req->cryptlen);
389
390	dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
391	if (unlikely(dst_len > U32_MAX)) {
392		pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
393		err = -EINVAL;
394		goto free;
395	}
396
397	dst_len = min_t(unsigned int, req->cryptlen, dst_len);
398	pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
399			req->cryptlen, dst_len);
400
401	if (unlikely(req->cryptlen + dst_len + ivsize +
402		sizeof(vc_req->status) > vcrypto->max_size)) {
403		pr_err("virtio_crypto: The length is too big\n");
404		err = -EINVAL;
405		goto free;
406	}
407
408	req_data->u.sym_req.u.cipher.para.dst_data_len =
409			cpu_to_le32((uint32_t)dst_len);
410
411	/* Outhdr */
412	sg_init_one(&outhdr, req_data, sizeof(*req_data));
413	sgs[num_out++] = &outhdr;
414
415	/* IV */
416
417	/*
418	 * Avoid to do DMA from the stack, switch to using
419	 * dynamically-allocated for the IV
420	 */
421	iv = kzalloc_node(ivsize, GFP_ATOMIC,
422				dev_to_node(&vcrypto->vdev->dev));
423	if (!iv) {
424		err = -ENOMEM;
425		goto free;
426	}
427	memcpy(iv, req->iv, ivsize);
428	if (!vc_sym_req->encrypt)
429		scatterwalk_map_and_copy(req->iv, req->src,
430					 req->cryptlen - AES_BLOCK_SIZE,
431					 AES_BLOCK_SIZE, 0);
432
433	sg_init_one(&iv_sg, iv, ivsize);
434	sgs[num_out++] = &iv_sg;
435	vc_sym_req->iv = iv;
436
437	/* Source data */
438	for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
439		sgs[num_out++] = sg;
440
441	/* Destination data */
442	for (sg = req->dst; sg; sg = sg_next(sg))
443		sgs[num_out + num_in++] = sg;
444
445	/* Status */
446	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
447	sgs[num_out + num_in++] = &status_sg;
448
449	vc_req->sgs = sgs;
450
451	spin_lock_irqsave(&data_vq->lock, flags);
452	err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
453				num_in, vc_req, GFP_ATOMIC);
454	virtqueue_kick(data_vq->vq);
455	spin_unlock_irqrestore(&data_vq->lock, flags);
456	if (unlikely(err < 0))
457		goto free_iv;
458
459	return 0;
460
461free_iv:
462	kfree_sensitive(iv);
463free:
464	kfree_sensitive(req_data);
465	kfree(sgs);
466	return err;
467}
468
469static int virtio_crypto_skcipher_encrypt(struct skcipher_request *req)
470{
471	struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
472	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm);
473	struct virtio_crypto_sym_request *vc_sym_req =
474				skcipher_request_ctx(req);
475	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
476	struct virtio_crypto *vcrypto = ctx->vcrypto;
477	/* Use the first data virtqueue as default */
478	struct data_queue *data_vq = &vcrypto->data_vq[0];
479
480	if (!req->cryptlen)
481		return 0;
482	if (req->cryptlen % AES_BLOCK_SIZE)
483		return -EINVAL;
484
485	vc_req->dataq = data_vq;
486	vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
487	vc_sym_req->skcipher_ctx = ctx;
488	vc_sym_req->skcipher_req = req;
489	vc_sym_req->encrypt = true;
490
491	return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req);
492}
493
494static int virtio_crypto_skcipher_decrypt(struct skcipher_request *req)
495{
496	struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
497	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm);
498	struct virtio_crypto_sym_request *vc_sym_req =
499				skcipher_request_ctx(req);
500	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
501	struct virtio_crypto *vcrypto = ctx->vcrypto;
502	/* Use the first data virtqueue as default */
503	struct data_queue *data_vq = &vcrypto->data_vq[0];
504
505	if (!req->cryptlen)
506		return 0;
507	if (req->cryptlen % AES_BLOCK_SIZE)
508		return -EINVAL;
509
510	vc_req->dataq = data_vq;
511	vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
512	vc_sym_req->skcipher_ctx = ctx;
513	vc_sym_req->skcipher_req = req;
514	vc_sym_req->encrypt = false;
515
516	return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req);
517}
518
519static int virtio_crypto_skcipher_init(struct crypto_skcipher *tfm)
520{
521	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
522
523	crypto_skcipher_set_reqsize(tfm, sizeof(struct virtio_crypto_sym_request));
524	ctx->tfm = tfm;
525
526	ctx->enginectx.op.do_one_request = virtio_crypto_skcipher_crypt_req;
527	ctx->enginectx.op.prepare_request = NULL;
528	ctx->enginectx.op.unprepare_request = NULL;
529	return 0;
530}
531
532static void virtio_crypto_skcipher_exit(struct crypto_skcipher *tfm)
533{
534	struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
535
536	if (!ctx->vcrypto)
537		return;
538
539	virtio_crypto_alg_skcipher_close_session(ctx, 1);
540	virtio_crypto_alg_skcipher_close_session(ctx, 0);
541	virtcrypto_dev_put(ctx->vcrypto);
542	ctx->vcrypto = NULL;
543}
544
545int virtio_crypto_skcipher_crypt_req(
546	struct crypto_engine *engine, void *vreq)
547{
548	struct skcipher_request *req = container_of(vreq, struct skcipher_request, base);
549	struct virtio_crypto_sym_request *vc_sym_req =
550				skcipher_request_ctx(req);
551	struct virtio_crypto_request *vc_req = &vc_sym_req->base;
552	struct data_queue *data_vq = vc_req->dataq;
553	int ret;
554
555	ret = __virtio_crypto_skcipher_do_req(vc_sym_req, req, data_vq);
556	if (ret < 0)
557		return ret;
558
559	virtqueue_kick(data_vq->vq);
560
561	return 0;
562}
563
564static void virtio_crypto_skcipher_finalize_req(
565	struct virtio_crypto_sym_request *vc_sym_req,
566	struct skcipher_request *req,
567	int err)
568{
569	if (vc_sym_req->encrypt)
570		scatterwalk_map_and_copy(req->iv, req->dst,
571					 req->cryptlen - AES_BLOCK_SIZE,
572					 AES_BLOCK_SIZE, 0);
573	kfree_sensitive(vc_sym_req->iv);
574	virtcrypto_clear_request(&vc_sym_req->base);
575
576	crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
577					   req, err);
578}
579
580static struct virtio_crypto_algo virtio_crypto_algs[] = { {
581	.algonum = VIRTIO_CRYPTO_CIPHER_AES_CBC,
582	.service = VIRTIO_CRYPTO_SERVICE_CIPHER,
583	.algo = {
584		.base.cra_name		= "cbc(aes)",
585		.base.cra_driver_name	= "virtio_crypto_aes_cbc",
586		.base.cra_priority	= 150,
587		.base.cra_flags		= CRYPTO_ALG_ASYNC |
588					  CRYPTO_ALG_ALLOCATES_MEMORY,
589		.base.cra_blocksize	= AES_BLOCK_SIZE,
590		.base.cra_ctxsize	= sizeof(struct virtio_crypto_skcipher_ctx),
591		.base.cra_module	= THIS_MODULE,
592		.init			= virtio_crypto_skcipher_init,
593		.exit			= virtio_crypto_skcipher_exit,
594		.setkey			= virtio_crypto_skcipher_setkey,
595		.decrypt		= virtio_crypto_skcipher_decrypt,
596		.encrypt		= virtio_crypto_skcipher_encrypt,
597		.min_keysize		= AES_MIN_KEY_SIZE,
598		.max_keysize		= AES_MAX_KEY_SIZE,
599		.ivsize			= AES_BLOCK_SIZE,
600	},
601} };
602
603int virtio_crypto_algs_register(struct virtio_crypto *vcrypto)
604{
605	int ret = 0;
606	int i = 0;
607
608	mutex_lock(&algs_lock);
609
610	for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
611
612		uint32_t service = virtio_crypto_algs[i].service;
613		uint32_t algonum = virtio_crypto_algs[i].algonum;
614
615		if (!virtcrypto_algo_is_supported(vcrypto, service, algonum))
616			continue;
617
618		if (virtio_crypto_algs[i].active_devs == 0) {
619			ret = crypto_register_skcipher(&virtio_crypto_algs[i].algo);
620			if (ret)
621				goto unlock;
622		}
623
624		virtio_crypto_algs[i].active_devs++;
625		dev_info(&vcrypto->vdev->dev, "Registered algo %s\n",
626			 virtio_crypto_algs[i].algo.base.cra_name);
627	}
628
629unlock:
630	mutex_unlock(&algs_lock);
631	return ret;
632}
633
634void virtio_crypto_algs_unregister(struct virtio_crypto *vcrypto)
635{
636	int i = 0;
637
638	mutex_lock(&algs_lock);
639
640	for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
641
642		uint32_t service = virtio_crypto_algs[i].service;
643		uint32_t algonum = virtio_crypto_algs[i].algonum;
644
645		if (virtio_crypto_algs[i].active_devs == 0 ||
646		    !virtcrypto_algo_is_supported(vcrypto, service, algonum))
647			continue;
648
649		if (virtio_crypto_algs[i].active_devs == 1)
650			crypto_unregister_skcipher(&virtio_crypto_algs[i].algo);
651
652		virtio_crypto_algs[i].active_devs--;
653	}
654
655	mutex_unlock(&algs_lock);
656}
657