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>

1 files changed, 476 insertions, 0 deletions

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>");