drivers/crypto/virtio/virtio_crypto_algs.c

   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
  19 struct 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
  28 struct 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
  40 struct 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  */
  51 static DEFINE_MUTEX(algs_lock);
  52 static void virtio_crypto_ablkcipher_finalize_req(
  53         struct virtio_crypto_sym_request *vc_sym_req,
  54         struct ablkcipher_request *req,
  55         int err);
  56
  57 static 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
  88 static 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
  98 static int
  99 virtio_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
 115 static 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 = kmalloc(keylen, GFP_ATOMIC);
 133
 134         if (!cipher_key)
 135                 return -ENOMEM;
 136
 137         memcpy(cipher_key, key, keylen);
 138
 139         spin_lock(&vcrypto->ctrl_lock);
 140         /* Pad ctrl header */
 141         vcrypto->ctrl.header.opcode =
 142                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
 143         vcrypto->ctrl.header.algo = cpu_to_le32(alg);
 144         /* Set the default dataqueue id to 0 */
 145         vcrypto->ctrl.header.queue_id = 0;
 146
 147         vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
 148         /* Pad cipher's parameters */
 149         vcrypto->ctrl.u.sym_create_session.op_type =
 150                 cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 151         vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
 152                 vcrypto->ctrl.header.algo;
 153         vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
 154                 cpu_to_le32(keylen);
 155         vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
 156                 cpu_to_le32(op);
 157
 158         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->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, &vcrypto->input, sizeof(vcrypto->input));
 167         sgs[num_out + num_in++] = &inhdr;
 168
 169         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 170                                 num_in, vcrypto, GFP_ATOMIC);
 171         if (err < 0) {
 172                 spin_unlock(&vcrypto->ctrl_lock);
 173                 kzfree(cipher_key);
 174                 return err;
 175         }
 176         virtqueue_kick(vcrypto->ctrl_vq);
 177
 178         /*
 179          * Trapping into the hypervisor, so the request should be
 180          * handled immediately.
 181          */
 182         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 183                !virtqueue_is_broken(vcrypto->ctrl_vq))
 184                 cpu_relax();
 185
 186         if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
 187                 spin_unlock(&vcrypto->ctrl_lock);
 188                 pr_err("virtio_crypto: Create session failed status: %u\n",
 189                         le32_to_cpu(vcrypto->input.status));
 190                 kzfree(cipher_key);
 191                 return -EINVAL;
 192         }
 193
 194         if (encrypt)
 195                 ctx->enc_sess_info.session_id =
 196                         le64_to_cpu(vcrypto->input.session_id);
 197         else
 198                 ctx->dec_sess_info.session_id =
 199                         le64_to_cpu(vcrypto->input.session_id);
 200
 201         spin_unlock(&vcrypto->ctrl_lock);
 202
 203         kzfree(cipher_key);
 204         return 0;
 205 }
 206
 207 static int virtio_crypto_alg_ablkcipher_close_session(
 208                 struct virtio_crypto_ablkcipher_ctx *ctx,
 209                 int encrypt)
 210 {
 211         struct scatterlist outhdr, status_sg, *sgs[2];
 212         unsigned int tmp;
 213         struct virtio_crypto_destroy_session_req *destroy_session;
 214         struct virtio_crypto *vcrypto = ctx->vcrypto;
 215         int err;
 216         unsigned int num_out = 0, num_in = 0;
 217
 218         spin_lock(&vcrypto->ctrl_lock);
 219         vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
 220         /* Pad ctrl header */
 221         vcrypto->ctrl.header.opcode =
 222                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
 223         /* Set the default virtqueue id to 0 */
 224         vcrypto->ctrl.header.queue_id = 0;
 225
 226         destroy_session = &vcrypto->ctrl.u.destroy_session;
 227
 228         if (encrypt)
 229                 destroy_session->session_id =
 230                         cpu_to_le64(ctx->enc_sess_info.session_id);
 231         else
 232                 destroy_session->session_id =
 233                         cpu_to_le64(ctx->dec_sess_info.session_id);
 234
 235         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 236         sgs[num_out++] = &outhdr;
 237
 238         /* Return status and session id back */
 239         sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
 240                 sizeof(vcrypto->ctrl_status.status));
 241         sgs[num_out + num_in++] = &status_sg;
 242
 243         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 244                         num_in, vcrypto, GFP_ATOMIC);
 245         if (err < 0) {
 246                 spin_unlock(&vcrypto->ctrl_lock);
 247                 return err;
 248         }
 249         virtqueue_kick(vcrypto->ctrl_vq);
 250
 251         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 252                !virtqueue_is_broken(vcrypto->ctrl_vq))
 253                 cpu_relax();
 254
 255         if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
 256                 spin_unlock(&vcrypto->ctrl_lock);
 257                 pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
 258                         vcrypto->ctrl_status.status,
 259                         destroy_session->session_id);
 260
 261                 return -EINVAL;
 262         }
 263         spin_unlock(&vcrypto->ctrl_lock);
 264
 265         return 0;
 266 }
 267
 268 static int virtio_crypto_alg_ablkcipher_init_sessions(
 269                 struct virtio_crypto_ablkcipher_ctx *ctx,
 270                 const uint8_t *key, unsigned int keylen)
 271 {
 272         uint32_t alg;
 273         int ret;
 274         struct virtio_crypto *vcrypto = ctx->vcrypto;
 275
 276         if (keylen > vcrypto->max_cipher_key_len) {
 277                 pr_err("virtio_crypto: the key is too long\n");
 278                 goto bad_key;
 279         }
 280
 281         if (virtio_crypto_alg_validate_key(keylen, &alg))
 282                 goto bad_key;
 283
 284         /* Create encryption session */
 285         ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
 286                         alg, key, keylen, 1);
 287         if (ret)
 288                 return ret;
 289         /* Create decryption session */
 290         ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
 291                         alg, key, keylen, 0);
 292         if (ret) {
 293                 virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 294                 return ret;
 295         }
 296         return 0;
 297
 298 bad_key:
 299         crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 300         return -EINVAL;
 301 }
 302
 303 /* Note: kernel crypto API realization */
 304 static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
 305                                          const uint8_t *key,
 306                                          unsigned int keylen)
 307 {
 308         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
 309         uint32_t alg;
 310         int ret;
 311
 312         ret = virtio_crypto_alg_validate_key(keylen, &alg);
 313         if (ret)
 314                 return ret;
 315
 316         if (!ctx->vcrypto) {
 317                 /* New key */
 318                 int node = virtio_crypto_get_current_node();
 319                 struct virtio_crypto *vcrypto =
 320                                       virtcrypto_get_dev_node(node,
 321                                       VIRTIO_CRYPTO_SERVICE_CIPHER, alg);
 322                 if (!vcrypto) {
 323                         pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n");
 324                         return -ENODEV;
 325                 }
 326
 327                 ctx->vcrypto = vcrypto;
 328         } else {
 329                 /* Rekeying, we should close the created sessions previously */
 330                 virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 331                 virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
 332         }
 333
 334         ret = virtio_crypto_alg_ablkcipher_init_sessions(ctx, key, keylen);
 335         if (ret) {
 336                 virtcrypto_dev_put(ctx->vcrypto);
 337                 ctx->vcrypto = NULL;
 338
 339                 return ret;
 340         }
 341
 342         return 0;
 343 }
 344
 345 static int
 346 __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 347                 struct ablkcipher_request *req,
 348                 struct data_queue *data_vq)
 349 {
 350         struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
 351         struct virtio_crypto_ablkcipher_ctx *ctx = vc_sym_req->ablkcipher_ctx;
 352         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 353         unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
 354         struct virtio_crypto *vcrypto = ctx->vcrypto;
 355         struct virtio_crypto_op_data_req *req_data;
 356         int src_nents, dst_nents;
 357         int err;
 358         unsigned long flags;
 359         struct scatterlist outhdr, iv_sg, status_sg, **sgs;
 360         int i;
 361         u64 dst_len;
 362         unsigned int num_out = 0, num_in = 0;
 363         int sg_total;
 364         uint8_t *iv;
 365
 366         src_nents = sg_nents_for_len(req->src, req->nbytes);
 367         dst_nents = sg_nents(req->dst);
 368
 369         pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
 370                         src_nents, dst_nents);
 371
 372         /* Why 3?  outhdr + iv + inhdr */
 373         sg_total = src_nents + dst_nents + 3;
 374         sgs = kcalloc_node(sg_total, sizeof(*sgs), GFP_KERNEL,
 375                                 dev_to_node(&vcrypto->vdev->dev));
 376         if (!sgs)
 377                 return -ENOMEM;
 378
 379         req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL,
 380                                 dev_to_node(&vcrypto->vdev->dev));
 381         if (!req_data) {
 382                 kfree(sgs);
 383                 return -ENOMEM;
 384         }
 385
 386         vc_req->req_data = req_data;
 387         vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
 388         /* Head of operation */
 389         if (vc_sym_req->encrypt) {
 390                 req_data->header.session_id =
 391                         cpu_to_le64(ctx->enc_sess_info.session_id);
 392                 req_data->header.opcode =
 393                         cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
 394         } else {
 395                 req_data->header.session_id =
 396                         cpu_to_le64(ctx->dec_sess_info.session_id);
 397                 req_data->header.opcode =
 398                         cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
 399         }
 400         req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 401         req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
 402         req_data->u.sym_req.u.cipher.para.src_data_len =
 403                         cpu_to_le32(req->nbytes);
 404
 405         dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
 406         if (unlikely(dst_len > U32_MAX)) {
 407                 pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
 408                 err = -EINVAL;
 409                 goto free;
 410         }
 411
 412         pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
 413                         req->nbytes, dst_len);
 414
 415         if (unlikely(req->nbytes + dst_len + ivsize +
 416                 sizeof(vc_req->status) > vcrypto->max_size)) {
 417                 pr_err("virtio_crypto: The length is too big\n");
 418                 err = -EINVAL;
 419                 goto free;
 420         }
 421
 422         req_data->u.sym_req.u.cipher.para.dst_data_len =
 423                         cpu_to_le32((uint32_t)dst_len);
 424
 425         /* Outhdr */
 426         sg_init_one(&outhdr, req_data, sizeof(*req_data));
 427         sgs[num_out++] = &outhdr;
 428
 429         /* IV */
 430
 431         /*
 432          * Avoid to do DMA from the stack, switch to using
 433          * dynamically-allocated for the IV
 434          */
 435         iv = kzalloc_node(ivsize, GFP_ATOMIC,
 436                                 dev_to_node(&vcrypto->vdev->dev));
 437         if (!iv) {
 438                 err = -ENOMEM;
 439                 goto free;
 440         }
 441         memcpy(iv, req->info, ivsize);
 442         sg_init_one(&iv_sg, iv, ivsize);
 443         sgs[num_out++] = &iv_sg;
 444         vc_sym_req->iv = iv;
 445
 446         /* Source data */
 447         for (i = 0; i < src_nents; i++)
 448                 sgs[num_out++] = &req->src[i];
 449
 450         /* Destination data */
 451         for (i = 0; i < dst_nents; i++)
 452                 sgs[num_out + num_in++] = &req->dst[i];
 453
 454         /* Status */
 455         sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
 456         sgs[num_out + num_in++] = &status_sg;
 457
 458         vc_req->sgs = sgs;
 459
 460         spin_lock_irqsave(&data_vq->lock, flags);
 461         err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
 462                                 num_in, vc_req, GFP_ATOMIC);
 463         virtqueue_kick(data_vq->vq);
 464         spin_unlock_irqrestore(&data_vq->lock, flags);
 465         if (unlikely(err < 0))
 466                 goto free_iv;
 467
 468         return 0;
 469
 470 free_iv:
 471         kzfree(iv);
 472 free:
 473         kzfree(req_data);
 474         kfree(sgs);
 475         return err;
 476 }
 477
 478 static int virtio_crypto_ablkcipher_encrypt(struct ablkcipher_request *req)
 479 {
 480         struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
 481         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
 482         struct virtio_crypto_sym_request *vc_sym_req =
 483                                 ablkcipher_request_ctx(req);
 484         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 485         struct virtio_crypto *vcrypto = ctx->vcrypto;
 486         /* Use the first data virtqueue as default */
 487         struct data_queue *data_vq = &vcrypto->data_vq[0];
 488
 489         vc_req->dataq = data_vq;
 490         vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
 491         vc_sym_req->ablkcipher_ctx = ctx;
 492         vc_sym_req->ablkcipher_req = req;
 493         vc_sym_req->encrypt = true;
 494
 495         return crypto_transfer_ablkcipher_request_to_engine(data_vq->engine, req);
 496 }
 497
 498 static int virtio_crypto_ablkcipher_decrypt(struct ablkcipher_request *req)
 499 {
 500         struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
 501         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
 502         struct virtio_crypto_sym_request *vc_sym_req =
 503                                 ablkcipher_request_ctx(req);
 504         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 505         struct virtio_crypto *vcrypto = ctx->vcrypto;
 506         /* Use the first data virtqueue as default */
 507         struct data_queue *data_vq = &vcrypto->data_vq[0];
 508
 509         vc_req->dataq = data_vq;
 510         vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
 511         vc_sym_req->ablkcipher_ctx = ctx;
 512         vc_sym_req->ablkcipher_req = req;
 513         vc_sym_req->encrypt = false;
 514
 515         return crypto_transfer_ablkcipher_request_to_engine(data_vq->engine, req);
 516 }
 517
 518 static int virtio_crypto_ablkcipher_init(struct crypto_tfm *tfm)
 519 {
 520         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
 521
 522         tfm->crt_ablkcipher.reqsize = sizeof(struct virtio_crypto_sym_request);
 523         ctx->tfm = tfm;
 524
 525         ctx->enginectx.op.do_one_request = virtio_crypto_ablkcipher_crypt_req;
 526         ctx->enginectx.op.prepare_request = NULL;
 527         ctx->enginectx.op.unprepare_request = NULL;
 528         return 0;
 529 }
 530
 531 static void virtio_crypto_ablkcipher_exit(struct crypto_tfm *tfm)
 532 {
 533         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
 534
 535         if (!ctx->vcrypto)
 536                 return;
 537
 538         virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 539         virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
 540         virtcrypto_dev_put(ctx->vcrypto);
 541         ctx->vcrypto = NULL;
 542 }
 543
 544 int virtio_crypto_ablkcipher_crypt_req(
 545         struct crypto_engine *engine, void *vreq)
 546 {
 547         struct ablkcipher_request *req = container_of(vreq, struct ablkcipher_request, base);
 548         struct virtio_crypto_sym_request *vc_sym_req =
 549                                 ablkcipher_request_ctx(req);
 550         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 551         struct data_queue *data_vq = vc_req->dataq;
 552         int ret;
 553
 554         ret = __virtio_crypto_ablkcipher_do_req(vc_sym_req, req, data_vq);
 555         if (ret < 0)
 556                 return ret;
 557
 558         virtqueue_kick(data_vq->vq);
 559
 560         return 0;
 561 }
 562
 563 static void virtio_crypto_ablkcipher_finalize_req(
 564         struct virtio_crypto_sym_request *vc_sym_req,
 565         struct ablkcipher_request *req,
 566         int err)
 567 {
 568         crypto_finalize_ablkcipher_request(vc_sym_req->base.dataq->engine,
 569                                            req, err);
 570         kzfree(vc_sym_req->iv);
 571         virtcrypto_clear_request(&vc_sym_req->base);
 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 = {
 578                 .cra_name = "cbc(aes)",
 579                 .cra_driver_name = "virtio_crypto_aes_cbc",
 580                 .cra_priority = 150,
 581                 .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
 582                 .cra_blocksize = AES_BLOCK_SIZE,
 583                 .cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
 584                 .cra_alignmask = 0,
 585                 .cra_module = THIS_MODULE,
 586                 .cra_type = &crypto_ablkcipher_type,
 587                 .cra_init = virtio_crypto_ablkcipher_init,
 588                 .cra_exit = virtio_crypto_ablkcipher_exit,
 589                 .cra_u = {
 590                         .ablkcipher = {
 591                                 .setkey = virtio_crypto_ablkcipher_setkey,
 592                                 .decrypt = virtio_crypto_ablkcipher_decrypt,
 593                                 .encrypt = virtio_crypto_ablkcipher_encrypt,
 594                                 .min_keysize = AES_MIN_KEY_SIZE,
 595                                 .max_keysize = AES_MAX_KEY_SIZE,
 596                                 .ivsize = AES_BLOCK_SIZE,
 597                         },
 598                 },
 599         },
 600 } };
 601
 602 int virtio_crypto_algs_register(struct virtio_crypto *vcrypto)
 603 {
 604         int ret = 0;
 605         int i = 0;
 606
 607         mutex_lock(&algs_lock);
 608
 609         for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
 610
 611                 uint32_t service = virtio_crypto_algs[i].service;
 612                 uint32_t algonum = virtio_crypto_algs[i].algonum;
 613
 614                 if (!virtcrypto_algo_is_supported(vcrypto, service, algonum))
 615                         continue;
 616
 617                 if (virtio_crypto_algs[i].active_devs == 0) {
 618                         ret = crypto_register_alg(&virtio_crypto_algs[i].algo);
 619                         if (ret)
 620                                 goto unlock;
 621                 }
 622
 623                 virtio_crypto_algs[i].active_devs++;
 624                 dev_info(&vcrypto->vdev->dev, "Registered algo %s\n",
 625                          virtio_crypto_algs[i].algo.cra_name);
 626         }
 627
 628 unlock:
 629         mutex_unlock(&algs_lock);
 630         return ret;
 631 }
 632
 633 void virtio_crypto_algs_unregister(struct virtio_crypto *vcrypto)
 634 {
 635         int i = 0;
 636
 637         mutex_lock(&algs_lock);
 638
 639         for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
 640
 641                 uint32_t service = virtio_crypto_algs[i].service;
 642                 uint32_t algonum = virtio_crypto_algs[i].algonum;
 643
 644                 if (virtio_crypto_algs[i].active_devs == 0 ||
 645                     !virtcrypto_algo_is_supported(vcrypto, service, algonum))
 646                         continue;
 647
 648                 if (virtio_crypto_algs[i].active_devs == 1)
 649                         crypto_unregister_alg(&virtio_crypto_algs[i].algo);
 650
 651                 virtio_crypto_algs[i].active_devs--;
 652         }
 653
 654         mutex_unlock(&algs_lock);
 655 }