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