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