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 <[email protected]>
   5   *
   6   * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
   7   */
   8
   9 #include <linux/scatterlist.h>
  10 #include <crypto/algapi.h>
  11 #include <crypto/internal/skcipher.h>
  12 #include <linux/err.h>
  13 #include <crypto/scatterwalk.h>
  14 #include <linux/atomic.h>
  15
  16 #include <uapi/linux/virtio_crypto.h>
  17 #include "virtio_crypto_common.h"
  18
  19
  20 struct virtio_crypto_skcipher_ctx {
  21         struct crypto_engine_ctx enginectx;
  22         struct virtio_crypto *vcrypto;
  23         struct crypto_skcipher *tfm;
  24
  25         struct virtio_crypto_sym_session_info enc_sess_info;
  26         struct virtio_crypto_sym_session_info dec_sess_info;
  27 };
  28
  29 struct virtio_crypto_sym_request {
  30         struct virtio_crypto_request base;
  31
  32         /* Cipher or aead */
  33         uint32_t type;
  34         struct virtio_crypto_skcipher_ctx *skcipher_ctx;
  35         struct skcipher_request *skcipher_req;
  36         uint8_t *iv;
  37         /* Encryption? */
  38         bool encrypt;
  39 };
  40
  41 struct virtio_crypto_algo {
  42         uint32_t algonum;
  43         uint32_t service;
  44         unsigned int active_devs;
  45         struct skcipher_alg algo;
  46 };
  47
  48 /*
  49  * The algs_lock protects the below global virtio_crypto_active_devs
  50  * and crypto algorithms registion.
  51  */
  52 static DEFINE_MUTEX(algs_lock);
  53 static void virtio_crypto_skcipher_finalize_req(
  54         struct virtio_crypto_sym_request *vc_sym_req,
  55         struct skcipher_request *req,
  56         int err);
  57
  58 static void virtio_crypto_dataq_sym_callback
  59                 (struct virtio_crypto_request *vc_req, int len)
  60 {
  61         struct virtio_crypto_sym_request *vc_sym_req =
  62                 container_of(vc_req, struct virtio_crypto_sym_request, base);
  63         struct skcipher_request *ablk_req;
  64         int error;
  65
  66         /* Finish the encrypt or decrypt process */
  67         if (vc_sym_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
  68                 switch (vc_req->status) {
  69                 case VIRTIO_CRYPTO_OK:
  70                         error = 0;
  71                         break;
  72                 case VIRTIO_CRYPTO_INVSESS:
  73                 case VIRTIO_CRYPTO_ERR:
  74                         error = -EINVAL;
  75                         break;
  76                 case VIRTIO_CRYPTO_BADMSG:
  77                         error = -EBADMSG;
  78                         break;
  79                 default:
  80                         error = -EIO;
  81                         break;
  82                 }
  83                 ablk_req = vc_sym_req->skcipher_req;
  84                 virtio_crypto_skcipher_finalize_req(vc_sym_req,
  85                                                         ablk_req, error);
  86         }
  87 }
  88
  89 static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
  90 {
  91         u64 total = 0;
  92
  93         for (total = 0; sg; sg = sg_next(sg))
  94                 total += sg->length;
  95
  96         return total;
  97 }
  98
  99 static int
 100 virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
 101 {
 102         switch (key_len) {
 103         case AES_KEYSIZE_128:
 104         case AES_KEYSIZE_192:
 105         case AES_KEYSIZE_256:
 106                 *alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
 107                 break;
 108         default:
 109                 return -EINVAL;
 110         }
 111         return 0;
 112 }
 113
 114 static int virtio_crypto_alg_skcipher_init_session(
 115                 struct virtio_crypto_skcipher_ctx *ctx,
 116                 uint32_t alg, const uint8_t *key,
 117                 unsigned int keylen,
 118                 int encrypt)
 119 {
 120         struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
 121         unsigned int tmp;
 122         struct virtio_crypto *vcrypto = ctx->vcrypto;
 123         int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
 124         int err;
 125         unsigned int num_out = 0, num_in = 0;
 126
 127         /*
 128          * Avoid to do DMA from the stack, switch to using
 129          * dynamically-allocated for the key
 130          */
 131         uint8_t *cipher_key = kmemdup(key, keylen, GFP_ATOMIC);
 132
 133         if (!cipher_key)
 134                 return -ENOMEM;
 135
 136         spin_lock(&vcrypto->ctrl_lock);
 137         /* Pad ctrl header */
 138         vcrypto->ctrl.header.opcode =
 139                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
 140         vcrypto->ctrl.header.algo = cpu_to_le32(alg);
 141         /* Set the default dataqueue id to 0 */
 142         vcrypto->ctrl.header.queue_id = 0;
 143
 144         vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
 145         /* Pad cipher's parameters */
 146         vcrypto->ctrl.u.sym_create_session.op_type =
 147                 cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 148         vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
 149                 vcrypto->ctrl.header.algo;
 150         vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
 151                 cpu_to_le32(keylen);
 152         vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
 153                 cpu_to_le32(op);
 154
 155         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 156         sgs[num_out++] = &outhdr;
 157
 158         /* Set key */
 159         sg_init_one(&key_sg, cipher_key, keylen);
 160         sgs[num_out++] = &key_sg;
 161
 162         /* Return status and session id back */
 163         sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
 164         sgs[num_out + num_in++] = &inhdr;
 165
 166         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 167                                 num_in, vcrypto, GFP_ATOMIC);
 168         if (err < 0) {
 169                 spin_unlock(&vcrypto->ctrl_lock);
 170                 kzfree(cipher_key);
 171                 return err;
 172         }
 173         virtqueue_kick(vcrypto->ctrl_vq);
 174
 175         /*
 176          * Trapping into the hypervisor, so the request should be
 177          * handled immediately.
 178          */
 179         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 180                !virtqueue_is_broken(vcrypto->ctrl_vq))
 181                 cpu_relax();
 182
 183         if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
 184                 spin_unlock(&vcrypto->ctrl_lock);
 185                 pr_err("virtio_crypto: Create session failed status: %u\n",
 186                         le32_to_cpu(vcrypto->input.status));
 187                 kzfree(cipher_key);
 188                 return -EINVAL;
 189         }
 190
 191         if (encrypt)
 192                 ctx->enc_sess_info.session_id =
 193                         le64_to_cpu(vcrypto->input.session_id);
 194         else
 195                 ctx->dec_sess_info.session_id =
 196                         le64_to_cpu(vcrypto->input.session_id);
 197
 198         spin_unlock(&vcrypto->ctrl_lock);
 199
 200         kzfree(cipher_key);
 201         return 0;
 202 }
 203
 204 static int virtio_crypto_alg_skcipher_close_session(
 205                 struct virtio_crypto_skcipher_ctx *ctx,
 206                 int encrypt)
 207 {
 208         struct scatterlist outhdr, status_sg, *sgs[2];
 209         unsigned int tmp;
 210         struct virtio_crypto_destroy_session_req *destroy_session;
 211         struct virtio_crypto *vcrypto = ctx->vcrypto;
 212         int err;
 213         unsigned int num_out = 0, num_in = 0;
 214
 215         spin_lock(&vcrypto->ctrl_lock);
 216         vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
 217         /* Pad ctrl header */
 218         vcrypto->ctrl.header.opcode =
 219                 cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
 220         /* Set the default virtqueue id to 0 */
 221         vcrypto->ctrl.header.queue_id = 0;
 222
 223         destroy_session = &vcrypto->ctrl.u.destroy_session;
 224
 225         if (encrypt)
 226                 destroy_session->session_id =
 227                         cpu_to_le64(ctx->enc_sess_info.session_id);
 228         else
 229                 destroy_session->session_id =
 230                         cpu_to_le64(ctx->dec_sess_info.session_id);
 231
 232         sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
 233         sgs[num_out++] = &outhdr;
 234
 235         /* Return status and session id back */
 236         sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
 237                 sizeof(vcrypto->ctrl_status.status));
 238         sgs[num_out + num_in++] = &status_sg;
 239
 240         err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
 241                         num_in, vcrypto, GFP_ATOMIC);
 242         if (err < 0) {
 243                 spin_unlock(&vcrypto->ctrl_lock);
 244                 return err;
 245         }
 246         virtqueue_kick(vcrypto->ctrl_vq);
 247
 248         while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
 249                !virtqueue_is_broken(vcrypto->ctrl_vq))
 250                 cpu_relax();
 251
 252         if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
 253                 spin_unlock(&vcrypto->ctrl_lock);
 254                 pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
 255                         vcrypto->ctrl_status.status,
 256                         destroy_session->session_id);
 257
 258                 return -EINVAL;
 259         }
 260         spin_unlock(&vcrypto->ctrl_lock);
 261
 262         return 0;
 263 }
 264
 265 static int virtio_crypto_alg_skcipher_init_sessions(
 266                 struct virtio_crypto_skcipher_ctx *ctx,
 267                 const uint8_t *key, unsigned int keylen)
 268 {
 269         uint32_t alg;
 270         int ret;
 271         struct virtio_crypto *vcrypto = ctx->vcrypto;
 272
 273         if (keylen > vcrypto->max_cipher_key_len) {
 274                 pr_err("virtio_crypto: the key is too long\n");
 275                 return -EINVAL;
 276         }
 277
 278         if (virtio_crypto_alg_validate_key(keylen, &alg))
 279                 return -EINVAL;
 280
 281         /* Create encryption session */
 282         ret = virtio_crypto_alg_skcipher_init_session(ctx,
 283                         alg, key, keylen, 1);
 284         if (ret)
 285                 return ret;
 286         /* Create decryption session */
 287         ret = virtio_crypto_alg_skcipher_init_session(ctx,
 288                         alg, key, keylen, 0);
 289         if (ret) {
 290                 virtio_crypto_alg_skcipher_close_session(ctx, 1);
 291                 return ret;
 292         }
 293         return 0;
 294 }
 295
 296 /* Note: kernel crypto API realization */
 297 static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm,
 298                                          const uint8_t *key,
 299                                          unsigned int keylen)
 300 {
 301         struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 302         uint32_t alg;
 303         int ret;
 304
 305         ret = virtio_crypto_alg_validate_key(keylen, &alg);
 306         if (ret)
 307                 return ret;
 308
 309         if (!ctx->vcrypto) {
 310                 /* New key */
 311                 int node = virtio_crypto_get_current_node();
 312                 struct virtio_crypto *vcrypto =
 313                                       virtcrypto_get_dev_node(node,
 314                                       VIRTIO_CRYPTO_SERVICE_CIPHER, alg);
 315                 if (!vcrypto) {
 316                         pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n");
 317                         return -ENODEV;
 318                 }
 319
 320                 ctx->vcrypto = vcrypto;
 321         } else {
 322                 /* Rekeying, we should close the created sessions previously */
 323                 virtio_crypto_alg_skcipher_close_session(ctx, 1);
 324                 virtio_crypto_alg_skcipher_close_session(ctx, 0);
 325         }
 326
 327         ret = virtio_crypto_alg_skcipher_init_sessions(ctx, key, keylen);
 328         if (ret) {
 329                 virtcrypto_dev_put(ctx->vcrypto);
 330                 ctx->vcrypto = NULL;
 331
 332                 return ret;
 333         }
 334
 335         return 0;
 336 }
 337
 338 static int
 339 __virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 340                 struct skcipher_request *req,
 341                 struct data_queue *data_vq)
 342 {
 343         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 344         struct virtio_crypto_skcipher_ctx *ctx = vc_sym_req->skcipher_ctx;
 345         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 346         unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 347         struct virtio_crypto *vcrypto = ctx->vcrypto;
 348         struct virtio_crypto_op_data_req *req_data;
 349         int src_nents, dst_nents;
 350         int err;
 351         unsigned long flags;
 352         struct scatterlist outhdr, iv_sg, status_sg, **sgs;
 353         int i;
 354         u64 dst_len;
 355         unsigned int num_out = 0, num_in = 0;
 356         int sg_total;
 357         uint8_t *iv;
 358
 359         src_nents = sg_nents_for_len(req->src, req->cryptlen);
 360         dst_nents = sg_nents(req->dst);
 361
 362         pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
 363                         src_nents, dst_nents);
 364
 365         /* Why 3?  outhdr + iv + inhdr */
 366         sg_total = src_nents + dst_nents + 3;
 367         sgs = kcalloc_node(sg_total, sizeof(*sgs), GFP_KERNEL,
 368                                 dev_to_node(&vcrypto->vdev->dev));
 369         if (!sgs)
 370                 return -ENOMEM;
 371
 372         req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL,
 373                                 dev_to_node(&vcrypto->vdev->dev));
 374         if (!req_data) {
 375                 kfree(sgs);
 376                 return -ENOMEM;
 377         }
 378
 379         vc_req->req_data = req_data;
 380         vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
 381         /* Head of operation */
 382         if (vc_sym_req->encrypt) {
 383                 req_data->header.session_id =
 384                         cpu_to_le64(ctx->enc_sess_info.session_id);
 385                 req_data->header.opcode =
 386                         cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
 387         } else {
 388                 req_data->header.session_id =
 389                         cpu_to_le64(ctx->dec_sess_info.session_id);
 390                 req_data->header.opcode =
 391                         cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
 392         }
 393         req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
 394         req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
 395         req_data->u.sym_req.u.cipher.para.src_data_len =
 396                         cpu_to_le32(req->cryptlen);
 397
 398         dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
 399         if (unlikely(dst_len > U32_MAX)) {
 400                 pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
 401                 err = -EINVAL;
 402                 goto free;
 403         }
 404
 405         pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
 406                         req->cryptlen, dst_len);
 407
 408         if (unlikely(req->cryptlen + dst_len + ivsize +
 409                 sizeof(vc_req->status) > vcrypto->max_size)) {
 410                 pr_err("virtio_crypto: The length is too big\n");
 411                 err = -EINVAL;
 412                 goto free;
 413         }
 414
 415         req_data->u.sym_req.u.cipher.para.dst_data_len =
 416                         cpu_to_le32((uint32_t)dst_len);
 417
 418         /* Outhdr */
 419         sg_init_one(&outhdr, req_data, sizeof(*req_data));
 420         sgs[num_out++] = &outhdr;
 421
 422         /* IV */
 423
 424         /*
 425          * Avoid to do DMA from the stack, switch to using
 426          * dynamically-allocated for the IV
 427          */
 428         iv = kzalloc_node(ivsize, GFP_ATOMIC,
 429                                 dev_to_node(&vcrypto->vdev->dev));
 430         if (!iv) {
 431                 err = -ENOMEM;
 432                 goto free;
 433         }
 434         memcpy(iv, req->iv, ivsize);
 435         if (!vc_sym_req->encrypt)
 436                 scatterwalk_map_and_copy(req->iv, req->src,
 437                                          req->cryptlen - AES_BLOCK_SIZE,
 438                                          AES_BLOCK_SIZE, 0);
 439
 440         sg_init_one(&iv_sg, iv, ivsize);
 441         sgs[num_out++] = &iv_sg;
 442         vc_sym_req->iv = iv;
 443
 444         /* Source data */
 445         for (i = 0; i < src_nents; i++)
 446                 sgs[num_out++] = &req->src[i];
 447
 448         /* Destination data */
 449         for (i = 0; i < dst_nents; i++)
 450                 sgs[num_out + num_in++] = &req->dst[i];
 451
 452         /* Status */
 453         sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
 454         sgs[num_out + num_in++] = &status_sg;
 455
 456         vc_req->sgs = sgs;
 457
 458         spin_lock_irqsave(&data_vq->lock, flags);
 459         err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
 460                                 num_in, vc_req, GFP_ATOMIC);
 461         virtqueue_kick(data_vq->vq);
 462         spin_unlock_irqrestore(&data_vq->lock, flags);
 463         if (unlikely(err < 0))
 464                 goto free_iv;
 465
 466         return 0;
 467
 468 free_iv:
 469         kzfree(iv);
 470 free:
 471         kzfree(req_data);
 472         kfree(sgs);
 473         return err;
 474 }
 475
 476 static int virtio_crypto_skcipher_encrypt(struct skcipher_request *req)
 477 {
 478         struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
 479         struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm);
 480         struct virtio_crypto_sym_request *vc_sym_req =
 481                                 skcipher_request_ctx(req);
 482         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 483         struct virtio_crypto *vcrypto = ctx->vcrypto;
 484         /* Use the first data virtqueue as default */
 485         struct data_queue *data_vq = &vcrypto->data_vq[0];
 486
 487         if (!req->cryptlen)
 488                 return 0;
 489         if (req->cryptlen % AES_BLOCK_SIZE)
 490                 return -EINVAL;
 491
 492         vc_req->dataq = data_vq;
 493         vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
 494         vc_sym_req->skcipher_ctx = ctx;
 495         vc_sym_req->skcipher_req = req;
 496         vc_sym_req->encrypt = true;
 497
 498         return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req);
 499 }
 500
 501 static int virtio_crypto_skcipher_decrypt(struct skcipher_request *req)
 502 {
 503         struct crypto_skcipher *atfm = crypto_skcipher_reqtfm(req);
 504         struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(atfm);
 505         struct virtio_crypto_sym_request *vc_sym_req =
 506                                 skcipher_request_ctx(req);
 507         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 508         struct virtio_crypto *vcrypto = ctx->vcrypto;
 509         /* Use the first data virtqueue as default */
 510         struct data_queue *data_vq = &vcrypto->data_vq[0];
 511
 512         if (!req->cryptlen)
 513                 return 0;
 514         if (req->cryptlen % AES_BLOCK_SIZE)
 515                 return -EINVAL;
 516
 517         vc_req->dataq = data_vq;
 518         vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
 519         vc_sym_req->skcipher_ctx = ctx;
 520         vc_sym_req->skcipher_req = req;
 521         vc_sym_req->encrypt = false;
 522
 523         return crypto_transfer_skcipher_request_to_engine(data_vq->engine, req);
 524 }
 525
 526 static int virtio_crypto_skcipher_init(struct crypto_skcipher *tfm)
 527 {
 528         struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 529
 530         crypto_skcipher_set_reqsize(tfm, sizeof(struct virtio_crypto_sym_request));
 531         ctx->tfm = tfm;
 532
 533         ctx->enginectx.op.do_one_request = virtio_crypto_skcipher_crypt_req;
 534         ctx->enginectx.op.prepare_request = NULL;
 535         ctx->enginectx.op.unprepare_request = NULL;
 536         return 0;
 537 }
 538
 539 static void virtio_crypto_skcipher_exit(struct crypto_skcipher *tfm)
 540 {
 541         struct virtio_crypto_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 542
 543         if (!ctx->vcrypto)
 544                 return;
 545
 546         virtio_crypto_alg_skcipher_close_session(ctx, 1);
 547         virtio_crypto_alg_skcipher_close_session(ctx, 0);
 548         virtcrypto_dev_put(ctx->vcrypto);
 549         ctx->vcrypto = NULL;
 550 }
 551
 552 int virtio_crypto_skcipher_crypt_req(
 553         struct crypto_engine *engine, void *vreq)
 554 {
 555         struct skcipher_request *req = container_of(vreq, struct skcipher_request, base);
 556         struct virtio_crypto_sym_request *vc_sym_req =
 557                                 skcipher_request_ctx(req);
 558         struct virtio_crypto_request *vc_req = &vc_sym_req->base;
 559         struct data_queue *data_vq = vc_req->dataq;
 560         int ret;
 561
 562         ret = __virtio_crypto_skcipher_do_req(vc_sym_req, req, data_vq);
 563         if (ret < 0)
 564                 return ret;
 565
 566         virtqueue_kick(data_vq->vq);
 567
 568         return 0;
 569 }
 570
 571 static void virtio_crypto_skcipher_finalize_req(
 572         struct virtio_crypto_sym_request *vc_sym_req,
 573         struct skcipher_request *req,
 574         int err)
 575 {
 576         if (vc_sym_req->encrypt)
 577                 scatterwalk_map_and_copy(req->iv, req->dst,
 578                                          req->cryptlen - AES_BLOCK_SIZE,
 579                                          AES_BLOCK_SIZE, 0);
 580         crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine,
 581                                            req, err);
 582         kzfree(vc_sym_req->iv);
 583         virtcrypto_clear_request(&vc_sym_req->base);
 584 }
 585
 586 static struct virtio_crypto_algo virtio_crypto_algs[] = { {
 587         .algonum = VIRTIO_CRYPTO_CIPHER_AES_CBC,
 588         .service = VIRTIO_CRYPTO_SERVICE_CIPHER,
 589         .algo = {
 590                 .base.cra_name          = "cbc(aes)",
 591                 .base.cra_driver_name   = "virtio_crypto_aes_cbc",
 592                 .base.cra_priority      = 150,
 593                 .base.cra_flags         = CRYPTO_ALG_ASYNC,
 594                 .base.cra_blocksize     = AES_BLOCK_SIZE,
 595                 .base.cra_ctxsize       = sizeof(struct virtio_crypto_skcipher_ctx),
 596                 .base.cra_module        = THIS_MODULE,
 597                 .init                   = virtio_crypto_skcipher_init,
 598                 .exit                   = virtio_crypto_skcipher_exit,
 599                 .setkey                 = virtio_crypto_skcipher_setkey,
 600                 .decrypt                = virtio_crypto_skcipher_decrypt,
 601                 .encrypt                = virtio_crypto_skcipher_encrypt,
 602                 .min_keysize            = AES_MIN_KEY_SIZE,
 603                 .max_keysize            = AES_MAX_KEY_SIZE,
 604                 .ivsize                 = AES_BLOCK_SIZE,
 605         },
 606 } };
 607
 608 int virtio_crypto_algs_register(struct virtio_crypto *vcrypto)
 609 {
 610         int ret = 0;
 611         int i = 0;
 612
 613         mutex_lock(&algs_lock);
 614
 615         for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
 616
 617                 uint32_t service = virtio_crypto_algs[i].service;
 618                 uint32_t algonum = virtio_crypto_algs[i].algonum;
 619
 620                 if (!virtcrypto_algo_is_supported(vcrypto, service, algonum))
 621                         continue;
 622
 623                 if (virtio_crypto_algs[i].active_devs == 0) {
 624                         ret = crypto_register_skcipher(&virtio_crypto_algs[i].algo);
 625                         if (ret)
 626                                 goto unlock;
 627                 }
 628
 629                 virtio_crypto_algs[i].active_devs++;
 630                 dev_info(&vcrypto->vdev->dev, "Registered algo %s\n",
 631                          virtio_crypto_algs[i].algo.base.cra_name);
 632         }
 633
 634 unlock:
 635         mutex_unlock(&algs_lock);
 636         return ret;
 637 }
 638
 639 void virtio_crypto_algs_unregister(struct virtio_crypto *vcrypto)
 640 {
 641         int i = 0;
 642
 643         mutex_lock(&algs_lock);
 644
 645         for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
 646
 647                 uint32_t service = virtio_crypto_algs[i].service;
 648                 uint32_t algonum = virtio_crypto_algs[i].algonum;
 649
 650                 if (virtio_crypto_algs[i].active_devs == 0 ||
 651                     !virtcrypto_algo_is_supported(vcrypto, service, algonum))
 652                         continue;
 653
 654                 if (virtio_crypto_algs[i].active_devs == 1)
 655                         crypto_unregister_skcipher(&virtio_crypto_algs[i].algo);
 656
 657                 virtio_crypto_algs[i].active_devs--;
 658         }
 659
 660         mutex_unlock(&algs_lock);
 661 }