drivers/crypto/virtio/virtio_crypto_algs.c

   1  /* Algorithms supported by virtio crypto device
   2   *
   3   * Authors: Gonglei <[email protected]>
   4   *
   5   * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
   6   *
   7   * This program is free software; you can redistribute it and/or modify
   8   * it under the terms of the GNU General Public License as published by
   9   * the Free Software Foundation; either version 2 of the License, or
  10   * (at your option) any later version.
  11   *
  12   * This program is distributed in the hope that it will be useful,
  13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   * GNU General Public License for more details.
  16   *
  17   * You should have received a copy of the GNU General Public License
  18   * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19   */
  20
  21 #include <linux/scatterlist.h>
  22 #include <crypto/algapi.h>
  23 #include <linux/err.h>
  24 #include <crypto/scatterwalk.h>
  25 #include <linux/atomic.h>
  26
  27 #include <uapi/linux/virtio_crypto.h>
  28 #include "virtio_crypto_common.h"
  29
  30
  31 struct virtio_crypto_ablkcipher_ctx {
  32         struct crypto_engine_ctx enginectx;
  33         struct virtio_crypto *vcrypto;
  34         struct crypto_tfm *tfm;
  35
  36         struct virtio_crypto_sym_session_info enc_sess_info;
  37         struct virtio_crypto_sym_session_info dec_sess_info;
  38 };
  39
  40 struct virtio_crypto_sym_request {
  41         struct virtio_crypto_request base;
  42
  43         /* Cipher or aead */
  44         uint32_t type;
  45         struct virtio_crypto_ablkcipher_ctx *ablkcipher_ctx;
  46         struct ablkcipher_request *ablkcipher_req;
  47         uint8_t *iv;
  48         /* Encryption? */
  49         bool encrypt;
  50 };
  51
  52 /*
  53  * The algs_lock protects the below global virtio_crypto_active_devs
  54  * and crypto algorithms registion.
  55  */
  56 static DEFINE_MUTEX(algs_lock);
  57 static unsigned int virtio_crypto_active_devs;
  58 static void virtio_crypto_ablkcipher_finalize_req(
  59         struct virtio_crypto_sym_request *vc_sym_req,
  60         struct ablkcipher_request *req,
  61         int err);
  62
  63 static void virtio_crypto_dataq_sym_callback
  64                 (struct virtio_crypto_request *vc_req, int len)
  65 {
  66         struct virtio_crypto_sym_request *vc_sym_req =
  67                 container_of(vc_req, struct virtio_crypto_sym_request, base);
  68         struct ablkcipher_request *ablk_req;
  69         int error;
  70
  71         /* Finish the encrypt or decrypt process */
  72         if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
  73                 switch (vc_req->status) {
  74                 case VIRTIO_CRYPTO_OK:
  75                         error = 0;
  76                         break;
  77                 case VIRTIO_CRYPTO_INVSESS:
  78                 case VIRTIO_CRYPTO_ERR:
  79                         error = -EINVAL;
  80                         break;
  81                 case VIRTIO_CRYPTO_BADMSG:
  82                         error = -EBADMSG;
  83                         break;
  84                 default:
  85                         error = -EIO;
  86                         break;
  87                 }
  88                 ablk_req = vc_sym_req->ablkcipher_req;
  89                 virtio_crypto_ablkcipher_finalize_req(vc_sym_req,
  90                                                         ablk_req, error);
  91         }
  92 }
  93
  94 static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
  95 {
  96         u64 total = 0;
  97
  98         for (total = 0; sg; sg = sg_next(sg))
  99                 total += sg->length;
 100
 101         return total;
 102 }
 103
 104 static int
 105 virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
 106 {
 107         switch (key_len) {
 108         case AES_KEYSIZE_128:
 109         case AES_KEYSIZE_192:
 110         case AES_KEYSIZE_256:
 111                 *alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
 112                 break;
 113         default:
 114                 pr_err("virtio_crypto: Unsupported key length: %d\n",
 115                         key_len);
 116                 return -EINVAL;
 117         }
 118         return 0;
 119 }
 120
 121 static int virtio_crypto_alg_ablkcipher_init_session(
 122                 struct virtio_crypto_ablkcipher_ctx *ctx,
 123                 uint32_t alg, const uint8_t *key,
 124                 unsigned int keylen,
 125                 int encrypt)
 126 {
 127         struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
 128         unsigned int tmp;
 129         struct virtio_crypto *vcrypto = ctx->vcrypto;
 130         int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
 131         int err;
 132         unsigned int num_out = 0, num_in = 0;
 133
 134         /*
 135          * Avoid to do DMA from the stack, switch to using
 136          * dynamically-allocated for the key
 137          */
 138         uint8_t *cipher_key = kmalloc(keylen, GFP_ATOMIC);
 139
 140         if (!cipher_key)
 141                 return -ENOMEM;
 142
 143         memcpy(cipher_key, key, keylen);
 144
 145         spin_lock(&vcrypto->ctrl_lock);
 146         /* Pad ctrl header */
 147         vcrypto->ctrl.header.opcode =
 148                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
 149         vcrypto->ctrl.header.algo = cpu_to_le32(alg);
 150         /* Set the default dataqueue id to 0 */
 151         vcrypto->ctrl.header.queue_id = 0;
 152
 153         vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
 154         /* Pad cipher's parameters */
 155         vcrypto->ctrl.u.sym_create_session.op_type =
 156                 cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 157         vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
 158                 vcrypto->ctrl.header.algo;
 159         vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
 160                 cpu_to_le32(keylen);
 161         vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
 162                 cpu_to_le32(op);
 163
 164         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 165         sgs[num_out++] = &outhdr;
 166
 167         /* Set key */
 168         sg_init_one(&key_sg, cipher_key, keylen);
 169         sgs[num_out++] = &key_sg;
 170
 171         /* Return status and session id back */
 172         sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
 173         sgs[num_out + num_in++] = &inhdr;
 174
 175         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 176                                 num_in, vcrypto, GFP_ATOMIC);
 177         if (err < 0) {
 178                 spin_unlock(&vcrypto->ctrl_lock);
 179                 kzfree(cipher_key);
 180                 return err;
 181         }
 182         virtqueue_kick(vcrypto->ctrl_vq);
 183
 184         /*
 185          * Trapping into the hypervisor, so the request should be
 186          * handled immediately.
 187          */
 188         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 189                !virtqueue_is_broken(vcrypto->ctrl_vq))
 190                 cpu_relax();
 191
 192         if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
 193                 spin_unlock(&vcrypto->ctrl_lock);
 194                 pr_err("virtio_crypto: Create session failed status: %u\n",
 195                         le32_to_cpu(vcrypto->input.status));
 196                 kzfree(cipher_key);
 197                 return -EINVAL;
 198         }
 199
 200         if (encrypt)
 201                 ctx->enc_sess_info.session_id =
 202                         le64_to_cpu(vcrypto->input.session_id);
 203         else
 204                 ctx->dec_sess_info.session_id =
 205                         le64_to_cpu(vcrypto->input.session_id);
 206
 207         spin_unlock(&vcrypto->ctrl_lock);
 208
 209         kzfree(cipher_key);
 210         return 0;
 211 }
 212
 213 static int virtio_crypto_alg_ablkcipher_close_session(
 214                 struct virtio_crypto_ablkcipher_ctx *ctx,
 215                 int encrypt)
 216 {
 217         struct scatterlist outhdr, status_sg, *sgs[2];
 218         unsigned int tmp;
 219         struct virtio_crypto_destroy_session_req *destroy_session;
 220         struct virtio_crypto *vcrypto = ctx->vcrypto;
 221         int err;
 222         unsigned int num_out = 0, num_in = 0;
 223
 224         spin_lock(&vcrypto->ctrl_lock);
 225         vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
 226         /* Pad ctrl header */
 227         vcrypto->ctrl.header.opcode =
 228                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
 229         /* Set the default virtqueue id to 0 */
 230         vcrypto->ctrl.header.queue_id = 0;
 231
 232         destroy_session = &vcrypto->ctrl.u.destroy_session;
 233
 234         if (encrypt)
 235                 destroy_session->session_id =
 236                         cpu_to_le64(ctx->enc_sess_info.session_id);
 237         else
 238                 destroy_session->session_id =
 239                         cpu_to_le64(ctx->dec_sess_info.session_id);
 240
 241         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 242         sgs[num_out++] = &outhdr;
 243
 244         /* Return status and session id back */
 245         sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
 246                 sizeof(vcrypto->ctrl_status.status));
 247         sgs[num_out + num_in++] = &status_sg;
 248
 249         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 250                         num_in, vcrypto, GFP_ATOMIC);
 251         if (err < 0) {
 252                 spin_unlock(&vcrypto->ctrl_lock);
 253                 return err;
 254         }
 255         virtqueue_kick(vcrypto->ctrl_vq);
 256
 257         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 258                !virtqueue_is_broken(vcrypto->ctrl_vq))
 259                 cpu_relax();
 260
 261         if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
 262                 spin_unlock(&vcrypto->ctrl_lock);
 263                 pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
 264                         vcrypto->ctrl_status.status,
 265                         destroy_session->session_id);
 266
 267                 return -EINVAL;
 268         }
 269         spin_unlock(&vcrypto->ctrl_lock);
 270
 271         return 0;
 272 }
 273
 274 static int virtio_crypto_alg_ablkcipher_init_sessions(
 275                 struct virtio_crypto_ablkcipher_ctx *ctx,
 276                 const uint8_t *key, unsigned int keylen)
 277 {
 278         uint32_t alg;
 279         int ret;
 280         struct virtio_crypto *vcrypto = ctx->vcrypto;
 281
 282         if (keylen > vcrypto->max_cipher_key_len) {
 283                 pr_err("virtio_crypto: the key is too long\n");
 284                 goto bad_key;
 285         }
 286
 287         if (virtio_crypto_alg_validate_key(keylen, &alg))
 288                 goto bad_key;
 289
 290         /* Create encryption session */
 291         ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
 292                         alg, key, keylen, 1);
 293         if (ret)
 294                 return ret;
 295         /* Create decryption session */
 296         ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
 297                         alg, key, keylen, 0);
 298         if (ret) {
 299                 virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
 300                 return ret;
 301         }
 302         return 0;
 303
 304 bad_key:
 305         crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 306         return -EINVAL;
 307 }
 308
 309 /* Note: kernel crypto API realization */
 310 static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
 311                                          const uint8_t *key,
 312                                          unsigned int keylen)
 313 {
 314         struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
 315         int ret;
 316
 317         if (!ctx->vcrypto) {
 318                 /* New key */
 319                 int node = virtio_crypto_get_current_node();
 320                 struct virtio_crypto *vcrypto =
 321                                       virtcrypto_get_dev_node(node);
 322                 if (!vcrypto) {
 323                         pr_err("virtio_crypto: Could not find a virtio device in the system\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_ATOMIC,
 375                                 dev_to_node(&vcrypto->vdev->dev));
 376         if (!sgs)
 377                 return -ENOMEM;
 378
 379         req_data = kzalloc_node(sizeof(*req_data), GFP_ATOMIC,
 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 crypto_alg virtio_crypto_algs[] = { {
 575         .cra_name = "cbc(aes)",
 576         .cra_driver_name = "virtio_crypto_aes_cbc",
 577         .cra_priority = 150,
 578         .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
 579         .cra_blocksize = AES_BLOCK_SIZE,
 580         .cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
 581         .cra_alignmask = 0,
 582         .cra_module = THIS_MODULE,
 583         .cra_type = &crypto_ablkcipher_type,
 584         .cra_init = virtio_crypto_ablkcipher_init,
 585         .cra_exit = virtio_crypto_ablkcipher_exit,
 586         .cra_u = {
 587            .ablkcipher = {
 588                         .setkey = virtio_crypto_ablkcipher_setkey,
 589                         .decrypt = virtio_crypto_ablkcipher_decrypt,
 590                         .encrypt = virtio_crypto_ablkcipher_encrypt,
 591                         .min_keysize = AES_MIN_KEY_SIZE,
 592                         .max_keysize = AES_MAX_KEY_SIZE,
 593                         .ivsize = AES_BLOCK_SIZE,
 594                 },
 595         },
 596 } };
 597
 598 int virtio_crypto_algs_register(void)
 599 {
 600         int ret = 0;
 601
 602         mutex_lock(&algs_lock);
 603         if (++virtio_crypto_active_devs != 1)
 604                 goto unlock;
 605
 606         ret = crypto_register_algs(virtio_crypto_algs,
 607                         ARRAY_SIZE(virtio_crypto_algs));
 608         if (ret)
 609                 virtio_crypto_active_devs--;
 610
 611 unlock:
 612         mutex_unlock(&algs_lock);
 613         return ret;
 614 }
 615
 616 void virtio_crypto_algs_unregister(void)
 617 {
 618         mutex_lock(&algs_lock);
 619         if (--virtio_crypto_active_devs != 0)
 620                 goto unlock;
 621
 622         crypto_unregister_algs(virtio_crypto_algs,
 623                         ARRAY_SIZE(virtio_crypto_algs));
 624
 625 unlock:
 626         mutex_unlock(&algs_lock);
 627 }