drivers/crypto/virtio/virtio_crypto_algs.c

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