crypto: add virtio-crypto driver

This patch introduces virtio-crypto driver for Linux Kernel.

The virtio crypto device is a virtual cryptography device
as well as a kind of virtual hardware accelerator for
virtual machines. The encryption anddecryption requests
are placed in the data queue and are ultimately handled by
thebackend crypto accelerators. The second queue is the
control queue used to create or destroy sessions for
symmetric algorithms and will control some advanced features
in the future. The virtio crypto device provides the following
cryptoservices: CIPHER, MAC, HASH, and AEAD.

For more information about virtio-crypto device, please see:
  http://qemu-project.org/Features/VirtioCrypto

CC: Michael S. Tsirkin <mst@redhat.com>
CC: Cornelia Huck <cornelia.huck@de.ibm.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Halil Pasic <pasic@linux.vnet.ibm.com>
CC: David S. Miller <davem@davemloft.net>
CC: Zeng Xin <xin.zeng@intel.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

6 files changed, 1423 insertions, 0 deletions

diff --git a/drivers/crypto/virtio/Kconfig b/drivers/crypto/virtio/Kconfig
new file mode 100644
index 000000000000..d80f73366ae2
--- /dev/null
+++ b/drivers/crypto/virtio/Kconfig
@@ -0,0 +1,10 @@
+config CRYPTO_DEV_VIRTIO
+	tristate "VirtIO crypto driver"
+	depends on VIRTIO
+	select CRYPTO_AEAD
+	select CRYPTO_AUTHENC
+	select CRYPTO_BLKCIPHER
+	default m
+	help
+	  This driver provides support for virtio crypto device. If you
+	  choose 'M' here, this module will be called virtio_crypto.
diff --git a/drivers/crypto/virtio/Makefile b/drivers/crypto/virtio/Makefile
new file mode 100644
index 000000000000..dd342c947ff9
--- /dev/null
+++ b/drivers/crypto/virtio/Makefile
@@ -0,0 +1,5 @@
+obj-$(CONFIG_CRYPTO_DEV_VIRTIO) += virtio_crypto.o
+virtio_crypto-objs := \
+	virtio_crypto_algs.o \
+	virtio_crypto_mgr.o \
+	virtio_crypto_core.o
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
new file mode 100644
index 000000000000..c2374df9abae
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -0,0 +1,540 @@
+ /* Algorithms supported by virtio crypto device
+  *
+  * Authors: Gonglei <arei.gonglei@huawei.com>
+  *
+  * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, see <http://www.gnu.org/licenses/>.
+  */
+
+#include <linux/scatterlist.h>
+#include <crypto/algapi.h>
+#include <linux/err.h>
+#include <crypto/scatterwalk.h>
+#include <linux/atomic.h>
+
+#include <uapi/linux/virtio_crypto.h>
+#include "virtio_crypto_common.h"
+
+/*
+ * The algs_lock protects the below global virtio_crypto_active_devs
+ * and crypto algorithms registion.
+ */
+static DEFINE_MUTEX(algs_lock);
+static unsigned int virtio_crypto_active_devs;
+
+static u64 virtio_crypto_alg_sg_nents_length(struct scatterlist *sg)
+{
+	u64 total = 0;
+
+	for (total = 0; sg; sg = sg_next(sg))
+		total += sg->length;
+
+	return total;
+}
+
+static int
+virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
+{
+	switch (key_len) {
+	case AES_KEYSIZE_128:
+	case AES_KEYSIZE_192:
+	case AES_KEYSIZE_256:
+		*alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
+		break;
+	default:
+		pr_err("virtio_crypto: Unsupported key length: %d\n",
+			key_len);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int virtio_crypto_alg_ablkcipher_init_session(
+		struct virtio_crypto_ablkcipher_ctx *ctx,
+		uint32_t alg, const uint8_t *key,
+		unsigned int keylen,
+		int encrypt)
+{
+	struct scatterlist outhdr, key_sg, inhdr, *sgs[3];
+	unsigned int tmp;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int op = encrypt ? VIRTIO_CRYPTO_OP_ENCRYPT : VIRTIO_CRYPTO_OP_DECRYPT;
+	int err;
+	unsigned int num_out = 0, num_in = 0;
+
+	/*
+	 * Avoid to do DMA from the stack, switch to using
+	 * dynamically-allocated for the key
+	 */
+	uint8_t *cipher_key = kmalloc(keylen, GFP_ATOMIC);
+
+	if (!cipher_key)
+		return -ENOMEM;
+
+	memcpy(cipher_key, key, keylen);
+
+	spin_lock(&vcrypto->ctrl_lock);
+	/* Pad ctrl header */
+	vcrypto->ctrl.header.opcode =
+		cpu_to_le32(VIRTIO_CRYPTO_CIPHER_CREATE_SESSION);
+	vcrypto->ctrl.header.algo = cpu_to_le32(alg);
+	/* Set the default dataqueue id to 0 */
+	vcrypto->ctrl.header.queue_id = 0;
+
+	vcrypto->input.status = cpu_to_le32(VIRTIO_CRYPTO_ERR);
+	/* Pad cipher's parameters */
+	vcrypto->ctrl.u.sym_create_session.op_type =
+		cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
+	vcrypto->ctrl.u.sym_create_session.u.cipher.para.algo =
+		vcrypto->ctrl.header.algo;
+	vcrypto->ctrl.u.sym_create_session.u.cipher.para.keylen =
+		cpu_to_le32(keylen);
+	vcrypto->ctrl.u.sym_create_session.u.cipher.para.op =
+		cpu_to_le32(op);
+
+	sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sgs[num_out++] = &outhdr;
+
+	/* Set key */
+	sg_init_one(&key_sg, cipher_key, keylen);
+	sgs[num_out++] = &key_sg;
+
+	/* Return status and session id back */
+	sg_init_one(&inhdr, &vcrypto->input, sizeof(vcrypto->input));
+	sgs[num_out + num_in++] = &inhdr;
+
+	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
+				num_in, vcrypto, GFP_ATOMIC);
+	if (err < 0) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		kzfree(cipher_key);
+		return err;
+	}
+	virtqueue_kick(vcrypto->ctrl_vq);
+
+	/*
+	 * Trapping into the hypervisor, so the request should be
+	 * handled immediately.
+	 */
+	while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
+	       !virtqueue_is_broken(vcrypto->ctrl_vq))
+		cpu_relax();
+
+	if (le32_to_cpu(vcrypto->input.status) != VIRTIO_CRYPTO_OK) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		pr_err("virtio_crypto: Create session failed status: %u\n",
+			le32_to_cpu(vcrypto->input.status));
+		kzfree(cipher_key);
+		return -EINVAL;
+	}
+
+	if (encrypt)
+		ctx->enc_sess_info.session_id =
+			le64_to_cpu(vcrypto->input.session_id);
+	else
+		ctx->dec_sess_info.session_id =
+			le64_to_cpu(vcrypto->input.session_id);
+
+	spin_unlock(&vcrypto->ctrl_lock);
+
+	kzfree(cipher_key);
+	return 0;
+}
+
+static int virtio_crypto_alg_ablkcipher_close_session(
+		struct virtio_crypto_ablkcipher_ctx *ctx,
+		int encrypt)
+{
+	struct scatterlist outhdr, status_sg, *sgs[2];
+	unsigned int tmp;
+	struct virtio_crypto_destroy_session_req *destroy_session;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int err;
+	unsigned int num_out = 0, num_in = 0;
+
+	spin_lock(&vcrypto->ctrl_lock);
+	vcrypto->ctrl_status.status = VIRTIO_CRYPTO_ERR;
+	/* Pad ctrl header */
+	vcrypto->ctrl.header.opcode =
+		cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DESTROY_SESSION);
+	/* Set the default virtqueue id to 0 */
+	vcrypto->ctrl.header.queue_id = 0;
+
+	destroy_session = &vcrypto->ctrl.u.destroy_session;
+
+	if (encrypt)
+		destroy_session->session_id =
+			cpu_to_le64(ctx->enc_sess_info.session_id);
+	else
+		destroy_session->session_id =
+			cpu_to_le64(ctx->dec_sess_info.session_id);
+
+	sg_init_one(&outhdr, &vcrypto->ctrl, sizeof(vcrypto->ctrl));
+	sgs[num_out++] = &outhdr;
+
+	/* Return status and session id back */
+	sg_init_one(&status_sg, &vcrypto->ctrl_status.status,
+		sizeof(vcrypto->ctrl_status.status));
+	sgs[num_out + num_in++] = &status_sg;
+
+	err = virtqueue_add_sgs(vcrypto->ctrl_vq, sgs, num_out,
+			num_in, vcrypto, GFP_ATOMIC);
+	if (err < 0) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		return err;
+	}
+	virtqueue_kick(vcrypto->ctrl_vq);
+
+	while (!virtqueue_get_buf(vcrypto->ctrl_vq, &tmp) &&
+	       !virtqueue_is_broken(vcrypto->ctrl_vq))
+		cpu_relax();
+
+	if (vcrypto->ctrl_status.status != VIRTIO_CRYPTO_OK) {
+		spin_unlock(&vcrypto->ctrl_lock);
+		pr_err("virtio_crypto: Close session failed status: %u, session_id: 0x%llx\n",
+			vcrypto->ctrl_status.status,
+			destroy_session->session_id);
+
+		return -EINVAL;
+	}
+	spin_unlock(&vcrypto->ctrl_lock);
+
+	return 0;
+}
+
+static int virtio_crypto_alg_ablkcipher_init_sessions(
+		struct virtio_crypto_ablkcipher_ctx *ctx,
+		const uint8_t *key, unsigned int keylen)
+{
+	uint32_t alg;
+	int ret;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+
+	if (keylen > vcrypto->max_cipher_key_len) {
+		pr_err("virtio_crypto: the key is too long\n");
+		goto bad_key;
+	}
+
+	if (virtio_crypto_alg_validate_key(keylen, &alg))
+		goto bad_key;
+
+	/* Create encryption session */
+	ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
+			alg, key, keylen, 1);
+	if (ret)
+		return ret;
+	/* Create decryption session */
+	ret = virtio_crypto_alg_ablkcipher_init_session(ctx,
+			alg, key, keylen, 0);
+	if (ret) {
+		virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
+		return ret;
+	}
+	return 0;
+
+bad_key:
+	crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+	return -EINVAL;
+}
+
+/* Note: kernel crypto API realization */
+static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
+					 const uint8_t *key,
+					 unsigned int keylen)
+{
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	int ret;
+
+	if (!ctx->vcrypto) {
+		/* New key */
+		int node = virtio_crypto_get_current_node();
+		struct virtio_crypto *vcrypto =
+				      virtcrypto_get_dev_node(node);
+		if (!vcrypto) {
+			pr_err("virtio_crypto: Could not find a virtio device in the system");
+			return -ENODEV;
+		}
+
+		ctx->vcrypto = vcrypto;
+	} else {
+		/* Rekeying, we should close the created sessions previously */
+		virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
+		virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
+	}
+
+	ret = virtio_crypto_alg_ablkcipher_init_sessions(ctx, key, keylen);
+	if (ret) {
+		virtcrypto_dev_put(ctx->vcrypto);
+		ctx->vcrypto = NULL;
+
+		return ret;
+	}
+
+	return 0;
+}
+
+static int
+__virtio_crypto_ablkcipher_do_req(struct virtio_crypto_request *vc_req,
+		struct ablkcipher_request *req,
+		struct data_queue *data_vq,
+		__u8 op)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	unsigned int ivsize = crypto_ablkcipher_ivsize(tfm);
+	struct virtio_crypto_ablkcipher_ctx *ctx = vc_req->ablkcipher_ctx;
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	struct virtio_crypto_op_data_req *req_data;
+	int src_nents, dst_nents;
+	int err;
+	unsigned long flags;
+	struct scatterlist outhdr, iv_sg, status_sg, **sgs;
+	int i;
+	u64 dst_len;
+	unsigned int num_out = 0, num_in = 0;
+	int sg_total;
+	uint8_t *iv;
+
+	src_nents = sg_nents_for_len(req->src, req->nbytes);
+	dst_nents = sg_nents(req->dst);
+
+	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
+			src_nents, dst_nents);
+
+	/* Why 3?  outhdr + iv + inhdr */
+	sg_total = src_nents + dst_nents + 3;
+	sgs = kzalloc_node(sg_total * sizeof(*sgs), GFP_ATOMIC,
+				dev_to_node(&vcrypto->vdev->dev));
+	if (!sgs)
+		return -ENOMEM;
+
+	req_data = kzalloc_node(sizeof(*req_data), GFP_ATOMIC,
+				dev_to_node(&vcrypto->vdev->dev));
+	if (!req_data) {
+		kfree(sgs);
+		return -ENOMEM;
+	}
+
+	vc_req->req_data = req_data;
+	vc_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
+	/* Head of operation */
+	if (op) {
+		req_data->header.session_id =
+			cpu_to_le64(ctx->enc_sess_info.session_id);
+		req_data->header.opcode =
+			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_ENCRYPT);
+	} else {
+		req_data->header.session_id =
+			cpu_to_le64(ctx->dec_sess_info.session_id);
+	    req_data->header.opcode =
+			cpu_to_le32(VIRTIO_CRYPTO_CIPHER_DECRYPT);
+	}
+	req_data->u.sym_req.op_type = cpu_to_le32(VIRTIO_CRYPTO_SYM_OP_CIPHER);
+	req_data->u.sym_req.u.cipher.para.iv_len = cpu_to_le32(ivsize);
+	req_data->u.sym_req.u.cipher.para.src_data_len =
+			cpu_to_le32(req->nbytes);
+
+	dst_len = virtio_crypto_alg_sg_nents_length(req->dst);
+	if (unlikely(dst_len > U32_MAX)) {
+		pr_err("virtio_crypto: The dst_len is beyond U32_MAX\n");
+		err = -EINVAL;
+		goto free;
+	}
+
+	pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
+			req->nbytes, dst_len);
+
+	if (unlikely(req->nbytes + dst_len + ivsize +
+		sizeof(vc_req->status) > vcrypto->max_size)) {
+		pr_err("virtio_crypto: The length is too big\n");
+		err = -EINVAL;
+		goto free;
+	}
+
+	req_data->u.sym_req.u.cipher.para.dst_data_len =
+			cpu_to_le32((uint32_t)dst_len);
+
+	/* Outhdr */
+	sg_init_one(&outhdr, req_data, sizeof(*req_data));
+	sgs[num_out++] = &outhdr;
+
+	/* IV */
+
+	/*
+	 * Avoid to do DMA from the stack, switch to using
+	 * dynamically-allocated for the IV
+	 */
+	iv = kzalloc_node(ivsize, GFP_ATOMIC,
+				dev_to_node(&vcrypto->vdev->dev));
+	if (!iv) {
+		err = -ENOMEM;
+		goto free;
+	}
+	memcpy(iv, req->info, ivsize);
+	sg_init_one(&iv_sg, iv, ivsize);
+	sgs[num_out++] = &iv_sg;
+	vc_req->iv = iv;
+
+	/* Source data */
+	for (i = 0; i < src_nents; i++)
+		sgs[num_out++] = &req->src[i];
+
+	/* Destination data */
+	for (i = 0; i < dst_nents; i++)
+		sgs[num_out + num_in++] = &req->dst[i];
+
+	/* Status */
+	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
+	sgs[num_out + num_in++] = &status_sg;
+
+	vc_req->sgs = sgs;
+
+	spin_lock_irqsave(&data_vq->lock, flags);
+	err = virtqueue_add_sgs(data_vq->vq, sgs, num_out,
+				num_in, vc_req, GFP_ATOMIC);
+	virtqueue_kick(data_vq->vq);
+	spin_unlock_irqrestore(&data_vq->lock, flags);
+	if (unlikely(err < 0))
+		goto free_iv;
+
+	return 0;
+
+free_iv:
+	kzfree(iv);
+free:
+	kzfree(req_data);
+	kfree(sgs);
+	return err;
+}
+
+static int virtio_crypto_ablkcipher_encrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
+	struct virtio_crypto_request *vc_req = ablkcipher_request_ctx(req);
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int ret;
+	/* Use the first data virtqueue as default */
+	struct data_queue *data_vq = &vcrypto->data_vq[0];
+
+	vc_req->ablkcipher_ctx = ctx;
+	vc_req->ablkcipher_req = req;
+	ret = __virtio_crypto_ablkcipher_do_req(vc_req, req, data_vq, 1);
+	if (ret < 0) {
+		pr_err("virtio_crypto: Encryption failed!\n");
+		return ret;
+	}
+
+	return -EINPROGRESS;
+}
+
+static int virtio_crypto_ablkcipher_decrypt(struct ablkcipher_request *req)
+{
+	struct crypto_ablkcipher *atfm = crypto_ablkcipher_reqtfm(req);
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(atfm);
+	struct virtio_crypto_request *vc_req = ablkcipher_request_ctx(req);
+	struct virtio_crypto *vcrypto = ctx->vcrypto;
+	int ret;
+	/* Use the first data virtqueue as default */
+	struct data_queue *data_vq = &vcrypto->data_vq[0];
+
+	vc_req->ablkcipher_ctx = ctx;
+	vc_req->ablkcipher_req = req;
+
+	ret = __virtio_crypto_ablkcipher_do_req(vc_req, req, data_vq, 0);
+	if (ret < 0) {
+		pr_err("virtio_crypto: Decryption failed!\n");
+		return ret;
+	}
+
+	return -EINPROGRESS;
+}
+
+static int virtio_crypto_ablkcipher_init(struct crypto_tfm *tfm)
+{
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct virtio_crypto_request);
+	ctx->tfm = tfm;
+
+	return 0;
+}
+
+static void virtio_crypto_ablkcipher_exit(struct crypto_tfm *tfm)
+{
+	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	if (!ctx->vcrypto)
+		return;
+
+	virtio_crypto_alg_ablkcipher_close_session(ctx, 1);
+	virtio_crypto_alg_ablkcipher_close_session(ctx, 0);
+	virtcrypto_dev_put(ctx->vcrypto);
+	ctx->vcrypto = NULL;
+}
+
+static struct crypto_alg virtio_crypto_algs[] = { {
+	.cra_name = "cbc(aes)",
+	.cra_driver_name = "virtio_crypto_aes_cbc",
+	.cra_priority = 501,
+	.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+	.cra_blocksize = AES_BLOCK_SIZE,
+	.cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
+	.cra_alignmask = 0,
+	.cra_module = THIS_MODULE,
+	.cra_type = &crypto_ablkcipher_type,
+	.cra_init = virtio_crypto_ablkcipher_init,
+	.cra_exit = virtio_crypto_ablkcipher_exit,
+	.cra_u = {
+	   .ablkcipher = {
+			.setkey = virtio_crypto_ablkcipher_setkey,
+			.decrypt = virtio_crypto_ablkcipher_decrypt,
+			.encrypt = virtio_crypto_ablkcipher_encrypt,
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.ivsize = AES_BLOCK_SIZE,
+		},
+	},
+} };
+
+int virtio_crypto_algs_register(void)
+{
+	int ret = 0;
+
+	mutex_lock(&algs_lock);
+	if (++virtio_crypto_active_devs != 1)
+		goto unlock;
+
+	ret = crypto_register_algs(virtio_crypto_algs,
+			ARRAY_SIZE(virtio_crypto_algs));
+	if (ret)
+		virtio_crypto_active_devs--;
+
+unlock:
+	mutex_unlock(&algs_lock);
+	return ret;
+}
+
+void virtio_crypto_algs_unregister(void)
+{
+	mutex_lock(&algs_lock);
+	if (--virtio_crypto_active_devs != 0)
+		goto unlock;
+
+	crypto_unregister_algs(virtio_crypto_algs,
+			ARRAY_SIZE(virtio_crypto_algs));
+
+unlock:
+	mutex_unlock(&algs_lock);
+}
diff --git a/drivers/crypto/virtio/virtio_crypto_common.h b/drivers/crypto/virtio/virtio_crypto_common.h
new file mode 100644
index 000000000000..3d6566b02876
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_common.h
@@ -0,0 +1,128 @@
+/* Common header for Virtio crypto device.
+ *
+ * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _VIRTIO_CRYPTO_COMMON_H
+#define _VIRTIO_CRYPTO_COMMON_H
+
+#include <linux/virtio.h>
+#include <linux/crypto.h>
+#include <linux/spinlock.h>
+#include <crypto/aead.h>
+#include <crypto/aes.h>
+#include <crypto/authenc.h>
+
+
+/* Internal representation of a data virtqueue */
+struct data_queue {
+	/* Virtqueue associated with this send _queue */
+	struct virtqueue *vq;
+
+	/* To protect the vq operations for the dataq */
+	spinlock_t lock;
+
+	/* Name of the tx queue: dataq.$index */
+	char name[32];
+};
+
+struct virtio_crypto {
+	struct virtio_device *vdev;
+	struct virtqueue *ctrl_vq;
+	struct data_queue *data_vq;
+
+	/* To protect the vq operations for the controlq */
+	spinlock_t ctrl_lock;
+
+	/* Maximum of data queues supported by the device */
+	u32 max_data_queues;
+
+	/* Number of queue currently used by the driver */
+	u32 curr_queue;
+
+	/* Maximum length of cipher key */
+	u32 max_cipher_key_len;
+	/* Maximum length of authenticated key */
+	u32 max_auth_key_len;
+	/* Maximum size of per request */
+	u64 max_size;
+
+	/* Control VQ buffers: protected by the ctrl_lock */
+	struct virtio_crypto_op_ctrl_req ctrl;
+	struct virtio_crypto_session_input input;
+	struct virtio_crypto_inhdr ctrl_status;
+
+	unsigned long status;
+	atomic_t ref_count;
+	struct list_head list;
+	struct module *owner;
+	uint8_t dev_id;
+
+	/* Does the affinity hint is set for virtqueues? */
+	bool affinity_hint_set;
+};
+
+struct virtio_crypto_sym_session_info {
+	/* Backend session id, which come from the host side */
+	__u64 session_id;
+};
+
+struct virtio_crypto_ablkcipher_ctx {
+	struct virtio_crypto *vcrypto;
+	struct crypto_tfm *tfm;
+
+	struct virtio_crypto_sym_session_info enc_sess_info;
+	struct virtio_crypto_sym_session_info dec_sess_info;
+};
+
+struct virtio_crypto_request {
+	/* Cipher or aead */
+	uint32_t type;
+	uint8_t status;
+	struct virtio_crypto_ablkcipher_ctx *ablkcipher_ctx;
+	struct ablkcipher_request *ablkcipher_req;
+	struct virtio_crypto_op_data_req *req_data;
+	struct scatterlist **sgs;
+	uint8_t *iv;
+};
+
+int virtcrypto_devmgr_add_dev(struct virtio_crypto *vcrypto_dev);
+struct list_head *virtcrypto_devmgr_get_head(void);
+void virtcrypto_devmgr_rm_dev(struct virtio_crypto *vcrypto_dev);
+struct virtio_crypto *virtcrypto_devmgr_get_first(void);
+int virtcrypto_dev_in_use(struct virtio_crypto *vcrypto_dev);
+int virtcrypto_dev_get(struct virtio_crypto *vcrypto_dev);
+void virtcrypto_dev_put(struct virtio_crypto *vcrypto_dev);
+int virtcrypto_dev_started(struct virtio_crypto *vcrypto_dev);
+struct virtio_crypto *virtcrypto_get_dev_node(int node);
+int virtcrypto_dev_start(struct virtio_crypto *vcrypto);
+void virtcrypto_dev_stop(struct virtio_crypto *vcrypto);
+
+static inline int virtio_crypto_get_current_node(void)
+{
+	int cpu, node;
+
+	cpu = get_cpu();
+	node = topology_physical_package_id(cpu);
+	put_cpu();
+
+	return node;
+}
+
+int virtio_crypto_algs_register(void);
+void virtio_crypto_algs_unregister(void);
+
+#endif /* _VIRTIO_CRYPTO_COMMON_H */
diff --git a/drivers/crypto/virtio/virtio_crypto_core.c b/drivers/crypto/virtio/virtio_crypto_core.c
new file mode 100644
index 000000000000..fe70ec823b27
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_core.c
@@ -0,0 +1,476 @@
+ /* Driver for Virtio crypto device.
+  *
+  * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, see <http://www.gnu.org/licenses/>.
+  */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/virtio_config.h>
+#include <linux/cpu.h>
+
+#include <uapi/linux/virtio_crypto.h>
+#include "virtio_crypto_common.h"
+
+
+static void
+virtcrypto_clear_request(struct virtio_crypto_request *vc_req)
+{
+	if (vc_req) {
+		kzfree(vc_req->iv);
+		kzfree(vc_req->req_data);
+		kfree(vc_req->sgs);
+	}
+}
+
+static void virtcrypto_dataq_callback(struct virtqueue *vq)
+{
+	struct virtio_crypto *vcrypto = vq->vdev->priv;
+	struct virtio_crypto_request *vc_req;
+	unsigned long flags;
+	unsigned int len;
+	struct ablkcipher_request *ablk_req;
+	int error;
+	unsigned int qid = vq->index;
+
+	spin_lock_irqsave(&vcrypto->data_vq[qid].lock, flags);
+	do {
+		virtqueue_disable_cb(vq);
+		while ((vc_req = virtqueue_get_buf(vq, &len)) != NULL) {
+			if (vc_req->type == VIRTIO_CRYPTO_SYM_OP_CIPHER) {
+				switch (vc_req->status) {
+				case VIRTIO_CRYPTO_OK:
+					error = 0;
+					break;
+				case VIRTIO_CRYPTO_INVSESS:
+				case VIRTIO_CRYPTO_ERR:
+					error = -EINVAL;
+					break;
+				case VIRTIO_CRYPTO_BADMSG:
+					error = -EBADMSG;
+					break;
+				default:
+					error = -EIO;
+					break;
+				}
+				ablk_req = vc_req->ablkcipher_req;
+				virtcrypto_clear_request(vc_req);
+
+				spin_unlock_irqrestore(
+					&vcrypto->data_vq[qid].lock, flags);
+				/* Finish the encrypt or decrypt process */
+				ablk_req->base.complete(&ablk_req->base, error);
+				spin_lock_irqsave(
+					&vcrypto->data_vq[qid].lock, flags);
+			}
+		}
+	} while (!virtqueue_enable_cb(vq));
+	spin_unlock_irqrestore(&vcrypto->data_vq[qid].lock, flags);
+}
+
+static int virtcrypto_find_vqs(struct virtio_crypto *vi)
+{
+	vq_callback_t **callbacks;
+	struct virtqueue **vqs;
+	int ret = -ENOMEM;
+	int i, total_vqs;
+	const char **names;
+
+	/*
+	 * We expect 1 data virtqueue, followed by
+	 * possible N-1 data queues used in multiqueue mode,
+	 * followed by control vq.
+	 */
+	total_vqs = vi->max_data_queues + 1;
+
+	/* Allocate space for find_vqs parameters */
+	vqs = kcalloc(total_vqs, sizeof(*vqs), GFP_KERNEL);
+	if (!vqs)
+		goto err_vq;
+	callbacks = kcalloc(total_vqs, sizeof(*callbacks), GFP_KERNEL);
+	if (!callbacks)
+		goto err_callback;
+	names = kcalloc(total_vqs, sizeof(*names), GFP_KERNEL);
+	if (!names)
+		goto err_names;
+
+	/* Parameters for control virtqueue */
+	callbacks[total_vqs - 1] = NULL;
+	names[total_vqs - 1] = "controlq";
+
+	/* Allocate/initialize parameters for data virtqueues */
+	for (i = 0; i < vi->max_data_queues; i++) {
+		callbacks[i] = virtcrypto_dataq_callback;
+		snprintf(vi->data_vq[i].name, sizeof(vi->data_vq[i].name),
+				"dataq.%d", i);
+		names[i] = vi->data_vq[i].name;
+	}
+
+	ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks,
+					 names);
+	if (ret)
+		goto err_find;
+
+	vi->ctrl_vq = vqs[total_vqs - 1];
+
+	for (i = 0; i < vi->max_data_queues; i++) {
+		spin_lock_init(&vi->data_vq[i].lock);
+		vi->data_vq[i].vq = vqs[i];
+	}
+
+	kfree(names);
+	kfree(callbacks);
+	kfree(vqs);
+
+	return 0;
+
+err_find:
+	kfree(names);
+err_names:
+	kfree(callbacks);
+err_callback:
+	kfree(vqs);
+err_vq:
+	return ret;
+}
+
+static int virtcrypto_alloc_queues(struct virtio_crypto *vi)
+{
+	vi->data_vq = kcalloc(vi->max_data_queues, sizeof(*vi->data_vq),
+				GFP_KERNEL);
+	if (!vi->data_vq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void virtcrypto_clean_affinity(struct virtio_crypto *vi, long hcpu)
+{
+	int i;
+
+	if (vi->affinity_hint_set) {
+		for (i = 0; i < vi->max_data_queues; i++)
+			virtqueue_set_affinity(vi->data_vq[i].vq, -1);
+
+		vi->affinity_hint_set = false;
+	}
+}
+
+static void virtcrypto_set_affinity(struct virtio_crypto *vcrypto)
+{
+	int i = 0;
+	int cpu;
+
+	/*
+	 * In single queue mode, we don't set the cpu affinity.
+	 */
+	if (vcrypto->curr_queue == 1 || vcrypto->max_data_queues == 1) {
+		virtcrypto_clean_affinity(vcrypto, -1);
+		return;
+	}
+
+	/*
+	 * In multiqueue mode, we let the queue to be private to one cpu
+	 * by setting the affinity hint to eliminate the contention.
+	 *
+	 * TODO: adds cpu hotplug support by register cpu notifier.
+	 *
+	 */
+	for_each_online_cpu(cpu) {
+		virtqueue_set_affinity(vcrypto->data_vq[i].vq, cpu);
+		if (++i >= vcrypto->max_data_queues)
+			break;
+	}
+
+	vcrypto->affinity_hint_set = true;
+}
+
+static void virtcrypto_free_queues(struct virtio_crypto *vi)
+{
+	kfree(vi->data_vq);
+}
+
+static int virtcrypto_init_vqs(struct virtio_crypto *vi)
+{
+	int ret;
+
+	/* Allocate send & receive queues */
+	ret = virtcrypto_alloc_queues(vi);
+	if (ret)
+		goto err;
+
+	ret = virtcrypto_find_vqs(vi);
+	if (ret)
+		goto err_free;
+
+	get_online_cpus();
+	virtcrypto_set_affinity(vi);
+	put_online_cpus();
+
+	return 0;
+
+err_free:
+	virtcrypto_free_queues(vi);
+err:
+	return ret;
+}
+
+static int virtcrypto_update_status(struct virtio_crypto *vcrypto)
+{
+	u32 status;
+	int err;
+
+	virtio_cread(vcrypto->vdev,
+	    struct virtio_crypto_config, status, &status);
+
+	/*
+	 * Unknown status bits would be a host error and the driver
+	 * should consider the device to be broken.
+	 */
+	if (status & (~VIRTIO_CRYPTO_S_HW_READY)) {
+		dev_warn(&vcrypto->vdev->dev,
+				"Unknown status bits: 0x%x\n", status);
+
+		virtio_break_device(vcrypto->vdev);
+		return -EPERM;
+	}
+
+	if (vcrypto->status == status)
+		return 0;
+
+	vcrypto->status = status;
+
+	if (vcrypto->status & VIRTIO_CRYPTO_S_HW_READY) {
+		err = virtcrypto_dev_start(vcrypto);
+		if (err) {
+			dev_err(&vcrypto->vdev->dev,
+				"Failed to start virtio crypto device.\n");
+
+			return -EPERM;
+		}
+		dev_info(&vcrypto->vdev->dev, "Accelerator is ready\n");
+	} else {
+		virtcrypto_dev_stop(vcrypto);
+		dev_info(&vcrypto->vdev->dev, "Accelerator is not ready\n");
+	}
+
+	return 0;
+}
+
+static void virtcrypto_del_vqs(struct virtio_crypto *vcrypto)
+{
+	struct virtio_device *vdev = vcrypto->vdev;
+
+	virtcrypto_clean_affinity(vcrypto, -1);
+
+	vdev->config->del_vqs(vdev);
+
+	virtcrypto_free_queues(vcrypto);
+}
+
+static int virtcrypto_probe(struct virtio_device *vdev)
+{
+	int err = -EFAULT;
+	struct virtio_crypto *vcrypto;
+	u32 max_data_queues = 0, max_cipher_key_len = 0;
+	u32 max_auth_key_len = 0;
+	u64 max_size = 0;
+
+	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
+		return -ENODEV;
+
+	if (!vdev->config->get) {
+		dev_err(&vdev->dev, "%s failure: config access disabled\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	if (num_possible_nodes() > 1 && dev_to_node(&vdev->dev) < 0) {
+		/*
+		 * If the accelerator is connected to a node with no memory
+		 * there is no point in using the accelerator since the remote
+		 * memory transaction will be very slow.
+		 */
+		dev_err(&vdev->dev, "Invalid NUMA configuration.\n");
+		return -EINVAL;
+	}
+
+	vcrypto = kzalloc_node(sizeof(*vcrypto), GFP_KERNEL,
+					dev_to_node(&vdev->dev));
+	if (!vcrypto)
+		return -ENOMEM;
+
+	virtio_cread(vdev, struct virtio_crypto_config,
+			max_dataqueues, &max_data_queues);
+	if (max_data_queues < 1)
+		max_data_queues = 1;
+
+	virtio_cread(vdev, struct virtio_crypto_config,
+		max_cipher_key_len, &max_cipher_key_len);
+	virtio_cread(vdev, struct virtio_crypto_config,
+		max_auth_key_len, &max_auth_key_len);
+	virtio_cread(vdev, struct virtio_crypto_config,
+		max_size, &max_size);
+
+	/* Add virtio crypto device to global table */
+	err = virtcrypto_devmgr_add_dev(vcrypto);
+	if (err) {
+		dev_err(&vdev->dev, "Failed to add new virtio crypto device.\n");
+		goto free;
+	}
+	vcrypto->owner = THIS_MODULE;
+	vcrypto = vdev->priv = vcrypto;
+	vcrypto->vdev = vdev;
+
+	spin_lock_init(&vcrypto->ctrl_lock);
+
+	/* Use single data queue as default */
+	vcrypto->curr_queue = 1;
+	vcrypto->max_data_queues = max_data_queues;
+	vcrypto->max_cipher_key_len = max_cipher_key_len;
+	vcrypto->max_auth_key_len = max_auth_key_len;
+	vcrypto->max_size = max_size;
+
+	dev_info(&vdev->dev,
+		"max_queues: %u, max_cipher_key_len: %u, max_auth_key_len: %u, max_size 0x%llx\n",
+		vcrypto->max_data_queues,
+		vcrypto->max_cipher_key_len,
+		vcrypto->max_auth_key_len,
+		vcrypto->max_size);
+
+	err = virtcrypto_init_vqs(vcrypto);
+	if (err) {
+		dev_err(&vdev->dev, "Failed to initialize vqs.\n");
+		goto free_dev;
+	}
+	virtio_device_ready(vdev);
+
+	err = virtcrypto_update_status(vcrypto);
+	if (err)
+		goto free_vqs;
+
+	return 0;
+
+free_vqs:
+	vcrypto->vdev->config->reset(vdev);
+	virtcrypto_del_vqs(vcrypto);
+free_dev:
+	virtcrypto_devmgr_rm_dev(vcrypto);
+free:
+	kfree(vcrypto);
+	return err;
+}
+
+static void virtcrypto_free_unused_reqs(struct virtio_crypto *vcrypto)
+{
+	struct virtio_crypto_request *vc_req;
+	int i;
+	struct virtqueue *vq;
+
+	for (i = 0; i < vcrypto->max_data_queues; i++) {
+		vq = vcrypto->data_vq[i].vq;
+		while ((vc_req = virtqueue_detach_unused_buf(vq)) != NULL) {
+			kfree(vc_req->req_data);
+			kfree(vc_req->sgs);
+		}
+	}
+}
+
+static void virtcrypto_remove(struct virtio_device *vdev)
+{
+	struct virtio_crypto *vcrypto = vdev->priv;
+
+	dev_info(&vdev->dev, "Start virtcrypto_remove.\n");
+
+	if (virtcrypto_dev_started(vcrypto))
+		virtcrypto_dev_stop(vcrypto);
+	vdev->config->reset(vdev);
+	virtcrypto_free_unused_reqs(vcrypto);
+	virtcrypto_del_vqs(vcrypto);
+	virtcrypto_devmgr_rm_dev(vcrypto);
+	kfree(vcrypto);
+}
+
+static void virtcrypto_config_changed(struct virtio_device *vdev)
+{
+	struct virtio_crypto *vcrypto = vdev->priv;
+
+	virtcrypto_update_status(vcrypto);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int virtcrypto_freeze(struct virtio_device *vdev)
+{
+	struct virtio_crypto *vcrypto = vdev->priv;
+
+	vdev->config->reset(vdev);
+	virtcrypto_free_unused_reqs(vcrypto);
+	if (virtcrypto_dev_started(vcrypto))
+		virtcrypto_dev_stop(vcrypto);
+
+	virtcrypto_del_vqs(vcrypto);
+	return 0;
+}
+
+static int virtcrypto_restore(struct virtio_device *vdev)
+{
+	struct virtio_crypto *vcrypto = vdev->priv;
+	int err;
+
+	err = virtcrypto_init_vqs(vcrypto);
+	if (err)
+		return err;
+
+	virtio_device_ready(vdev);
+	err = virtcrypto_dev_start(vcrypto);
+	if (err) {
+		dev_err(&vdev->dev, "Failed to start virtio crypto device.\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+#endif
+
+static unsigned int features[] = {
+	/* none */
+};
+
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_CRYPTO, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct virtio_driver virtio_crypto_driver = {
+	.driver.name         = KBUILD_MODNAME,
+	.driver.owner        = THIS_MODULE,
+	.feature_table       = features,
+	.feature_table_size  = ARRAY_SIZE(features),
+	.id_table            = id_table,
+	.probe               = virtcrypto_probe,
+	.remove              = virtcrypto_remove,
+	.config_changed = virtcrypto_config_changed,
+#ifdef CONFIG_PM_SLEEP
+	.freeze = virtcrypto_freeze,
+	.restore = virtcrypto_restore,
+#endif
+};
+
+module_virtio_driver(virtio_crypto_driver);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("virtio crypto device driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gonglei <arei.gonglei@huawei.com>");
diff --git a/drivers/crypto/virtio/virtio_crypto_mgr.c b/drivers/crypto/virtio/virtio_crypto_mgr.c
new file mode 100644
index 000000000000..a69ff71de2c4
--- /dev/null
+++ b/drivers/crypto/virtio/virtio_crypto_mgr.c
@@ -0,0 +1,264 @@
+ /* Management for virtio crypto devices (refer to adf_dev_mgr.c)
+  *
+  * Copyright 2016 HUAWEI TECHNOLOGIES CO., LTD.
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, see <http://www.gnu.org/licenses/>.
+  */
+
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+#include <uapi/linux/virtio_crypto.h>
+#include "virtio_crypto_common.h"
+
+static LIST_HEAD(virtio_crypto_table);
+static uint32_t num_devices;
+
+/* The table_lock protects the above global list and num_devices */
+static DEFINE_MUTEX(table_lock);
+
+#define VIRTIO_CRYPTO_MAX_DEVICES 32
+
+
+/*
+ * virtcrypto_devmgr_add_dev() - Add vcrypto_dev to the acceleration
+ * framework.
+ * @vcrypto_dev:  Pointer to virtio crypto device.
+ *
+ * Function adds virtio crypto device to the global list.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 0 on success, error code othewise.
+ */
+int virtcrypto_devmgr_add_dev(struct virtio_crypto *vcrypto_dev)
+{
+	struct list_head *itr;
+
+	mutex_lock(&table_lock);
+	if (num_devices == VIRTIO_CRYPTO_MAX_DEVICES) {
+		pr_info("virtio_crypto: only support up to %d devices\n",
+			    VIRTIO_CRYPTO_MAX_DEVICES);
+		mutex_unlock(&table_lock);
+		return -EFAULT;
+	}
+
+	list_for_each(itr, &virtio_crypto_table) {
+		struct virtio_crypto *ptr =
+				list_entry(itr, struct virtio_crypto, list);
+
+		if (ptr == vcrypto_dev) {
+			mutex_unlock(&table_lock);
+			return -EEXIST;
+		}
+	}
+	atomic_set(&vcrypto_dev->ref_count, 0);
+	list_add_tail(&vcrypto_dev->list, &virtio_crypto_table);
+	vcrypto_dev->dev_id = num_devices++;
+	mutex_unlock(&table_lock);
+	return 0;
+}
+
+struct list_head *virtcrypto_devmgr_get_head(void)
+{
+	return &virtio_crypto_table;
+}
+
+/*
+ * virtcrypto_devmgr_rm_dev() - Remove vcrypto_dev from the acceleration
+ * framework.
+ * @vcrypto_dev:  Pointer to virtio crypto device.
+ *
+ * Function removes virtio crypto device from the acceleration framework.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: void
+ */
+void virtcrypto_devmgr_rm_dev(struct virtio_crypto *vcrypto_dev)
+{
+	mutex_lock(&table_lock);
+	list_del(&vcrypto_dev->list);
+	num_devices--;
+	mutex_unlock(&table_lock);
+}
+
+/*
+ * virtcrypto_devmgr_get_first()
+ *
+ * Function returns the first virtio crypto device from the acceleration
+ * framework.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: pointer to vcrypto_dev or NULL if not found.
+ */
+struct virtio_crypto *virtcrypto_devmgr_get_first(void)
+{
+	struct virtio_crypto *dev = NULL;
+
+	mutex_lock(&table_lock);
+	if (!list_empty(&virtio_crypto_table))
+		dev = list_first_entry(&virtio_crypto_table,
+					struct virtio_crypto,
+				    list);
+	mutex_unlock(&table_lock);
+	return dev;
+}
+
+/*
+ * virtcrypto_dev_in_use() - Check whether vcrypto_dev is currently in use
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 1 when device is in use, 0 otherwise.
+ */
+int virtcrypto_dev_in_use(struct virtio_crypto *vcrypto_dev)
+{
+	return atomic_read(&vcrypto_dev->ref_count) != 0;
+}
+
+/*
+ * virtcrypto_dev_get() - Increment vcrypto_dev reference count
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * Increment the vcrypto_dev refcount and if this is the first time
+ * incrementing it during this period the vcrypto_dev is in use,
+ * increment the module refcount too.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 0 when successful, EFAULT when fail to bump module refcount
+ */
+int virtcrypto_dev_get(struct virtio_crypto *vcrypto_dev)
+{
+	if (atomic_add_return(1, &vcrypto_dev->ref_count) == 1)
+		if (!try_module_get(vcrypto_dev->owner))
+			return -EFAULT;
+	return 0;
+}
+
+/*
+ * virtcrypto_dev_put() - Decrement vcrypto_dev reference count
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * Decrement the vcrypto_dev refcount and if this is the last time
+ * decrementing it during this period the vcrypto_dev is in use,
+ * decrement the module refcount too.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: void
+ */
+void virtcrypto_dev_put(struct virtio_crypto *vcrypto_dev)
+{
+	if (atomic_sub_return(1, &vcrypto_dev->ref_count) == 0)
+		module_put(vcrypto_dev->owner);
+}
+
+/*
+ * virtcrypto_dev_started() - Check whether device has started
+ * @vcrypto_dev: Pointer to virtio crypto device.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 1 when the device has started, 0 otherwise
+ */
+int virtcrypto_dev_started(struct virtio_crypto *vcrypto_dev)
+{
+	return (vcrypto_dev->status & VIRTIO_CRYPTO_S_HW_READY);
+}
+
+/*
+ * virtcrypto_get_dev_node() - Get vcrypto_dev on the node.
+ * @node:  Node id the driver works.
+ *
+ * Function returns the virtio crypto device used fewest on the node.
+ *
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: pointer to vcrypto_dev or NULL if not found.
+ */
+struct virtio_crypto *virtcrypto_get_dev_node(int node)
+{
+	struct virtio_crypto *vcrypto_dev = NULL, *tmp_dev;
+	unsigned long best = ~0;
+	unsigned long ctr;
+
+	mutex_lock(&table_lock);
+	list_for_each_entry(tmp_dev, virtcrypto_devmgr_get_head(), list) {
+
+		if ((node == dev_to_node(&tmp_dev->vdev->dev) ||
+		     dev_to_node(&tmp_dev->vdev->dev) < 0) &&
+		    virtcrypto_dev_started(tmp_dev)) {
+			ctr = atomic_read(&tmp_dev->ref_count);
+			if (best > ctr) {
+				vcrypto_dev = tmp_dev;
+				best = ctr;
+			}
+		}
+	}
+
+	if (!vcrypto_dev) {
+		pr_info("virtio_crypto: Could not find a device on node %d\n",
+				node);
+		/* Get any started device */
+		list_for_each_entry(tmp_dev,
+				virtcrypto_devmgr_get_head(), list) {
+			if (virtcrypto_dev_started(tmp_dev)) {
+				vcrypto_dev = tmp_dev;
+				break;
+			}
+		}
+	}
+	mutex_unlock(&table_lock);
+	if (!vcrypto_dev)
+		return NULL;
+
+	virtcrypto_dev_get(vcrypto_dev);
+	return vcrypto_dev;
+}
+
+/*
+ * virtcrypto_dev_start() - Start virtio crypto device
+ * @vcrypto:    Pointer to virtio crypto device.
+ *
+ * Function notifies all the registered services that the virtio crypto device
+ * is ready to be used.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: 0 on success, EFAULT when fail to register algorithms
+ */
+int virtcrypto_dev_start(struct virtio_crypto *vcrypto)
+{
+	if (virtio_crypto_algs_register()) {
+		pr_err("virtio_crypto: Failed to register crypto algs\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+/*
+ * virtcrypto_dev_stop() - Stop virtio crypto device
+ * @vcrypto:    Pointer to virtio crypto device.
+ *
+ * Function notifies all the registered services that the virtio crypto device
+ * is ready to be used.
+ * To be used by virtio crypto device specific drivers.
+ *
+ * Return: void
+ */
+void virtcrypto_dev_stop(struct virtio_crypto *vcrypto)
+{
+	virtio_crypto_algs_unregister();
+}