// SPDX-License-Identifier: GPL-2.0/* * Amazon Nitro Secure Module driver. * * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. * * The Nitro Secure Module implements commands via CBOR over virtio. * This driver exposes a raw message ioctls on /dev/nsm that user * space can use to issue these commands. */ #include <linux/file.h>#include <linux/fs.h>#include <linux/interrupt.h>#include <linux/hw_random.h>#include <linux/miscdevice.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/slab.h>#include <linux/string.h>#include <linux/uaccess.h>#include <linux/uio.h>#include <linux/virtio_config.h>#include <linux/virtio_ids.h>#include <linux/virtio.h>#include <linux/wait.h>#include <uapi/linux/nsm.h> /* Timeout for NSM virtqueue respose in milliseconds. */#define NSM_DEFAULT_TIMEOUT_MSECS (120000) /* 2 minutes */ /* Maximum length input data */struct nsm_data_req { u32 len; u8 data[NSM_REQUEST_MAX_SIZE];}; /* Maximum length output data */struct nsm_data_resp { u32 len; u8 data[NSM_RESPONSE_MAX_SIZE];}; /* Full NSM request/response message */struct nsm_msg { struct nsm_data_req req; struct nsm_data_resp resp;}; struct nsm { struct virtio_device *vdev; struct virtqueue *vq; struct mutex lock; struct completion cmd_done; struct miscdevice misc; struct hwrng hwrng; struct work_struct misc_init; struct nsm_msg msg;}; /* NSM device ID */static const struct virtio_device_id id_table[] = { { VIRTIO_ID_NITRO_SEC_MOD, VIRTIO_DEV_ANY_ID }, { }}; static struct nsm *file_to_nsm(struct file *file){ return container_of(file->private_data, struct nsm, misc);} static struct nsm *hwrng_to_nsm(struct hwrng *rng){ return container_of(rng, struct nsm, hwrng);} #define CBOR_TYPE_MASK 0xE0#define CBOR_TYPE_MAP 0xA0#define CBOR_TYPE_TEXT 0x60#define CBOR_TYPE_ARRAY 0x40#define CBOR_HEADER_SIZE_SHORT 1 #define CBOR_SHORT_SIZE_MAX_VALUE 23#define CBOR_LONG_SIZE_U8 24#define CBOR_LONG_SIZE_U16 25#define CBOR_LONG_SIZE_U32 26#define CBOR_LONG_SIZE_U64 27 static bool cbor_object_is_array(const u8 *cbor_object, size_t cbor_object_size){ if (cbor_object_size == 0 || cbor_object == NULL) return false; return (cbor_object[0] & CBOR_TYPE_MASK) == CBOR_TYPE_ARRAY;} static int cbor_object_get_array(u8 *cbor_object, size_t cbor_object_size, u8 **cbor_array){ u8 cbor_short_size; void *array_len_p; u64 array_len; u64 array_offset; if (!cbor_object_is_array(cbor_object, cbor_object_size)) return -EFAULT; cbor_short_size = (cbor_object[0] & 0x1F); /* Decoding byte array length */ array_offset = CBOR_HEADER_SIZE_SHORT; if (cbor_short_size >= CBOR_LONG_SIZE_U8) array_offset += BIT(cbor_short_size - CBOR_LONG_SIZE_U8); if (cbor_object_size < array_offset) return -EFAULT; array_len_p = &cbor_object[1]; switch (cbor_short_size) { case CBOR_SHORT_SIZE_MAX_VALUE: /* short encoding */ array_len = cbor_short_size; break; case CBOR_LONG_SIZE_U8: array_len = *(u8 *)array_len_p; break; case CBOR_LONG_SIZE_U16: array_len = be16_to_cpup((__be16 *)array_len_p); break; case CBOR_LONG_SIZE_U32: array_len = be32_to_cpup((__be32 *)array_len_p); break; case CBOR_LONG_SIZE_U64: array_len = be64_to_cpup((__be64 *)array_len_p); break; } if (cbor_object_size < array_offset) return -EFAULT; if (cbor_object_size - array_offset < array_len) return -EFAULT; if (array_len > INT_MAX) return -EFAULT; *cbor_array = cbor_object + array_offset; return array_len;} /* Copy the request of a raw message to kernel space */static int fill_req_raw(struct nsm *nsm, struct nsm_data_req *req, struct nsm_raw *raw){ /* Verify the user input size. */ if (raw->request.len > sizeof(req->data)) return -EMSGSIZE; /* Copy the request payload */ if (copy_from_user(req->data, u64_to_user_ptr(raw->request.addr), raw->request.len)) return -EFAULT; req->len = raw->request.len; return 0;} /* Copy the response of a raw message back to user-space */static int parse_resp_raw(struct nsm *nsm, struct nsm_data_resp *resp, struct nsm_raw *raw){ /* Truncate any message that does not fit. */ raw->response.len = min_t(u64, raw->response.len, resp->len); /* Copy the response content to user space */ if (copy_to_user(u64_to_user_ptr(raw->response.addr), resp->data, raw->response.len)) return -EFAULT; return 0;} /* Virtqueue interrupt handler */static void nsm_vq_callback(struct virtqueue *vq){ struct nsm *nsm = vq->vdev->priv; complete(&nsm->cmd_done);} /* Forward a message to the NSM device and wait for the response from it */static int nsm_sendrecv_msg_locked(struct nsm *nsm){ struct device *dev = &nsm->vdev->dev; struct scatterlist sg_in, sg_out; struct nsm_msg *msg = &nsm->msg; struct virtqueue *vq = nsm->vq; unsigned int len; void *queue_buf; bool kicked; int rc; /* Initialize scatter-gather lists with request and response buffers. */ sg_init_one(&sg_out, msg->req.data, msg->req.len); sg_init_one(&sg_in, msg->resp.data, sizeof(msg->resp.data)); init_completion(&nsm->cmd_done); /* Add the request buffer (read by the device). */ rc = virtqueue_add_outbuf(vq, &sg_out, 1, msg->req.data, GFP_KERNEL); if (rc) return rc; /* Add the response buffer (written by the device). */ rc = virtqueue_add_inbuf(vq, &sg_in, 1, msg->resp.data, GFP_KERNEL); if (rc) goto cleanup; kicked = virtqueue_kick(vq); if (!kicked) { /* Cannot kick the virtqueue. */ rc = -EIO; goto cleanup; } /* If the kick succeeded, wait for the device's response. */ if (!wait_for_completion_io_timeout(&nsm->cmd_done, msecs_to_jiffies(NSM_DEFAULT_TIMEOUT_MSECS))) { rc = -ETIMEDOUT; goto cleanup; } queue_buf = virtqueue_get_buf(vq, &len); if (!queue_buf || (queue_buf != msg->req.data)) { dev_err(dev, "wrong request buffer."); rc = -ENODATA; goto cleanup; } queue_buf = virtqueue_get_buf(vq, &len); if (!queue_buf || (queue_buf != msg->resp.data)) { dev_err(dev, "wrong response buffer."); rc = -ENODATA; goto cleanup; } msg->resp.len = min_t(unsigned int, len, sizeof(msg->resp.data)); rc = 0; cleanup: if (rc) { /* Clean the virtqueue. */ while (virtqueue_get_buf(vq, &len) != NULL) ; } return rc;} static int fill_req_get_random(struct nsm *nsm, struct nsm_data_req *req){ /* * 69 # text(9) * 47657452616E646F6D # "GetRandom" */ const u8 request[] = { CBOR_TYPE_TEXT + strlen("GetRandom"), 'G', 'e', 't', 'R', 'a', 'n', 'd', 'o', 'm' }; memcpy(req->data, request, sizeof(request)); req->len = sizeof(request); return 0;} static int parse_resp_get_random(struct nsm *nsm, struct nsm_data_resp *resp, void *out, size_t max){ /* * A1 # map(1) * 69 # text(9) - Name of field * 47657452616E646F6D # "GetRandom" * A1 # map(1) - The field itself * 66 # text(6) * 72616E646F6D # "random" * # The rest of the response is random data */ const u8 response[] = { CBOR_TYPE_MAP + 1, CBOR_TYPE_TEXT + strlen("GetRandom"), 'G', 'e', 't', 'R', 'a', 'n', 'd', 'o', 'm', CBOR_TYPE_MAP + 1, CBOR_TYPE_TEXT + strlen("random"), 'r', 'a', 'n', 'd', 'o', 'm' }; struct device *dev = &nsm->vdev->dev; u8 *rand_data = NULL; u8 *resp_ptr = resp->data; u64 resp_len = resp->len; int rc; if ((resp->len < sizeof(response) + 1) || (memcmp(resp_ptr, response, sizeof(response)) != 0)) { dev_err(dev, "Invalid response for GetRandom"); return -EFAULT; } resp_ptr += sizeof(response); resp_len -= sizeof(response); rc = cbor_object_get_array(resp_ptr, resp_len, &rand_data); if (rc < 0) { dev_err(dev, "GetRandom: Invalid CBOR encoding\n"); return rc; } rc = min_t(size_t, rc, max); memcpy(out, rand_data, rc); return rc;} /* * HwRNG implementation */static int nsm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait){ struct nsm *nsm = hwrng_to_nsm(rng); struct device *dev = &nsm->vdev->dev; int rc = 0; /* NSM always needs to wait for a response */ if (!wait) return 0; mutex_lock(&nsm->lock); rc = fill_req_get_random(nsm, &nsm->msg.req); if (rc != 0) goto out; rc = nsm_sendrecv_msg_locked(nsm); if (rc != 0) goto out; rc = parse_resp_get_random(nsm, &nsm->msg.resp, data, max); if (rc < 0) goto out; dev_dbg(dev, "RNG: returning rand bytes = %d", rc);out: mutex_unlock(&nsm->lock); return rc;} static long nsm_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ void __user *argp = u64_to_user_ptr((u64)arg); struct nsm *nsm = file_to_nsm(file); struct nsm_raw raw; int r = 0; if (cmd != NSM_IOCTL_RAW) return -EINVAL; if (_IOC_SIZE(cmd) != sizeof(raw)) return -EINVAL; /* Copy user argument struct to kernel argument struct */ if (copy_from_user(&raw, argp, _IOC_SIZE(cmd))) return -EFAULT; mutex_lock(&nsm->lock); /* Convert kernel argument struct to device request */ r = fill_req_raw(nsm, &nsm->msg.req, &raw); if (r) goto out; /* Send message to NSM and read reply */ r = nsm_sendrecv_msg_locked(nsm); if (r) goto out; /* Parse device response into kernel argument struct */ r = parse_resp_raw(nsm, &nsm->msg.resp, &raw); if (r) goto out; /* Copy kernel argument struct back to user argument struct */ r = -EFAULT; if (copy_to_user(argp, &raw, sizeof(raw))) goto out; r = 0; out: mutex_unlock(&nsm->lock); return r;} static int nsm_device_init_vq(struct virtio_device *vdev){ struct virtqueue *vq = virtio_find_single_vq(vdev, nsm_vq_callback, "nsm.vq.0"); struct nsm *nsm = vdev->priv; if (IS_ERR(vq)) return PTR_ERR(vq); nsm->vq = vq; return 0;} static const struct file_operations nsm_dev_fops = { .owner = THIS_MODULE, .unlocked_ioctl = nsm_dev_ioctl, .compat_ioctl = compat_ptr_ioctl,}; /* Handler for probing the NSM device */static int nsm_device_probe(struct virtio_device *vdev){ struct device *dev = &vdev->dev; struct nsm *nsm; int rc; nsm = devm_kzalloc(&vdev->dev, sizeof(*nsm), GFP_KERNEL); if (!nsm) return -ENOMEM; vdev->priv = nsm; nsm->vdev = vdev; rc = nsm_device_init_vq(vdev); if (rc) { dev_err(dev, "queue failed to initialize: %d.\n", rc); goto err_init_vq; } mutex_init(&nsm->lock); /* Register as hwrng provider */ nsm->hwrng = (struct hwrng) { .read = nsm_rng_read, .name = "nsm-hwrng", .quality = 1000, }; rc = hwrng_register(&nsm->hwrng); if (rc) { dev_err(dev, "RNG initialization error: %d.\n", rc); goto err_hwrng; } /* Register /dev/nsm device node */ nsm->misc = (struct miscdevice) { .minor = MISC_DYNAMIC_MINOR, .name = "nsm", .fops = &nsm_dev_fops, .mode = 0666, }; rc = misc_register(&nsm->misc); if (rc) { dev_err(dev, "misc device registration error: %d.\n", rc); goto err_misc; } return 0; err_misc: hwrng_unregister(&nsm->hwrng);err_hwrng: vdev->config->del_vqs(vdev);err_init_vq: return rc;} /* Handler for removing the NSM device */static void nsm_device_remove(struct virtio_device *vdev){ struct nsm *nsm = vdev->priv; hwrng_unregister(&nsm->hwrng); vdev->config->del_vqs(vdev); misc_deregister(&nsm->misc);} /* NSM device configuration structure */static struct virtio_driver virtio_nsm_driver = { .feature_table = 0, .feature_table_size = 0, .feature_table_legacy = 0, .feature_table_size_legacy = 0, .driver.name = KBUILD_MODNAME, .id_table = id_table, .probe = nsm_device_probe, .remove = nsm_device_remove,};Lines 1–500 of 505. 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// SPDX-License-Identifier: GPL-2.0 /* * Amazon Nitro Secure Module driver. * * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. * * The Nitro Secure Module implements commands via CBOR over virtio. * This driver exposes a raw message ioctls on /dev/nsm that user * space can use to issue these commands. */ #include <linux/file.h> #include <linux/fs.h> #include <linux/interrupt.h> #include <linux/hw_random.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/uaccess.h> #include <linux/uio.h> #include <linux/virtio_config.h> #include <linux/virtio_ids.h> #include <linux/virtio.h> #include <linux/wait.h> #include <uapi/linux/nsm.h> /* Timeout for NSM virtqueue respose in milliseconds. */ #define NSM_DEFAULT_TIMEOUT_MSECS (120000) /* 2 minutes */ /* Maximum length input data */ struct nsm_data_req { u32 len; u8 data[NSM_REQUEST_MAX_SIZE]; }; /* Maximum length output data */ struct nsm_data_resp { u32 len; u8 data[NSM_RESPONSE_MAX_SIZE]; }; /* Full NSM request/response message */ struct nsm_msg { struct nsm_data_req req; struct nsm_data_resp resp; }; struct nsm { struct virtio_device *vdev; struct virtqueue *vq; struct mutex lock; struct completion cmd_done; struct miscdevice misc; struct hwrng hwrng; struct work_struct misc_init; struct nsm_msg msg; }; /* NSM device ID */ static const struct virtio_device_id id_table[] = { { VIRTIO_ID_NITRO_SEC_MOD, VIRTIO_DEV_ANY_ID }, { } }; static struct nsm *file_to_nsm(struct file *file) { return container_of(file->private_data, struct nsm, misc); } static struct nsm *hwrng_to_nsm(struct hwrng *rng) { return container_of(rng, struct nsm, hwrng); } #define CBOR_TYPE_MASK 0xE0 #define CBOR_TYPE_MAP 0xA0 #define CBOR_TYPE_TEXT 0x60 #define CBOR_TYPE_ARRAY 0x40 #define CBOR_HEADER_SIZE_SHORT 1 #define CBOR_SHORT_SIZE_MAX_VALUE 23 #define CBOR_LONG_SIZE_U8 24 #define CBOR_LONG_SIZE_U16 25 #define CBOR_LONG_SIZE_U32 26 #define CBOR_LONG_SIZE_U64 27 static bool cbor_object_is_array(const u8 *cbor_object, size_t cbor_object_size) { if (cbor_object_size == 0 || cbor_object == NULL) return false; return (cbor_object[0] & CBOR_TYPE_MASK) == CBOR_TYPE_ARRAY; } static int cbor_object_get_array(u8 *cbor_object, size_t cbor_object_size, u8 **cbor_array) { u8 cbor_short_size; void *array_len_p; u64 array_len; u64 array_offset; if (!cbor_object_is_array(cbor_object, cbor_object_size)) return -EFAULT; cbor_short_size = (cbor_object[0] & 0x1F); /* Decoding byte array length */ array_offset = CBOR_HEADER_SIZE_SHORT; if (cbor_short_size >= CBOR_LONG_SIZE_U8) array_offset += BIT(cbor_short_size - CBOR_LONG_SIZE_U8); if (cbor_object_size < array_offset) return -EFAULT; array_len_p = &cbor_object[1]; switch (cbor_short_size) { case CBOR_SHORT_SIZE_MAX_VALUE: /* short encoding */ array_len = cbor_short_size; break; case CBOR_LONG_SIZE_U8: array_len = *(u8 *)array_len_p; break; case CBOR_LONG_SIZE_U16: array_len = be16_to_cpup((__be16 *)array_len_p); break; case CBOR_LONG_SIZE_U32: array_len = be32_to_cpup((__be32 *)array_len_p); break; case CBOR_LONG_SIZE_U64: array_len = be64_to_cpup((__be64 *)array_len_p); break; } if (cbor_object_size < array_offset) return -EFAULT; if (cbor_object_size - array_offset < array_len) return -EFAULT; if (array_len > INT_MAX) return -EFAULT; *cbor_array = cbor_object + array_offset; return array_len; } /* Copy the request of a raw message to kernel space */ static int fill_req_raw(struct nsm *nsm, struct nsm_data_req *req, struct nsm_raw *raw) { /* Verify the user input size. */ if (raw->request.len > sizeof(req->data)) return -EMSGSIZE; /* Copy the request payload */ if (copy_from_user(req->data, u64_to_user_ptr(raw->request.addr), raw->request.len)) return -EFAULT; req->len = raw->request.len; return 0; } /* Copy the response of a raw message back to user-space */ static int parse_resp_raw(struct nsm *nsm, struct nsm_data_resp *resp, struct nsm_raw *raw) { /* Truncate any message that does not fit. */ raw->response.len = min_t(u64, raw->response.len, resp->len); /* Copy the response content to user space */ if (copy_to_user(u64_to_user_ptr(raw->response.addr), resp->data, raw->response.len)) return -EFAULT; return 0; } /* Virtqueue interrupt handler */ static void nsm_vq_callback(struct virtqueue *vq) { struct nsm *nsm = vq->vdev->priv; complete(&nsm->cmd_done); } /* Forward a message to the NSM device and wait for the response from it */ static int nsm_sendrecv_msg_locked(struct nsm *nsm) { struct device *dev = &nsm->vdev->dev; struct scatterlist sg_in, sg_out; struct nsm_msg *msg = &nsm->msg; struct virtqueue *vq = nsm->vq; unsigned int len; void *queue_buf; bool kicked; int rc; /* Initialize scatter-gather lists with request and response buffers. */ sg_init_one(&sg_out, msg->req.data, msg->req.len); sg_init_one(&sg_in, msg->resp.data, sizeof(msg->resp.data)); init_completion(&nsm->cmd_done); /* Add the request buffer (read by the device). */ rc = virtqueue_add_outbuf(vq, &sg_out, 1, msg->req.data, GFP_KERNEL); if (rc) return rc; /* Add the response buffer (written by the device). */ rc = virtqueue_add_inbuf(vq, &sg_in, 1, msg->resp.data, GFP_KERNEL); if (rc) goto cleanup; kicked = virtqueue_kick(vq); if (!kicked) { /* Cannot kick the virtqueue. */ rc = -EIO; goto cleanup; } /* If the kick succeeded, wait for the device's response. */ if (!wait_for_completion_io_timeout(&nsm->cmd_done, msecs_to_jiffies(NSM_DEFAULT_TIMEOUT_MSECS))) { rc = -ETIMEDOUT; goto cleanup; } queue_buf = virtqueue_get_buf(vq, &len); if (!queue_buf || (queue_buf != msg->req.data)) { dev_err(dev, "wrong request buffer."); rc = -ENODATA; goto cleanup; } queue_buf = virtqueue_get_buf(vq, &len); if (!queue_buf || (queue_buf != msg->resp.data)) { dev_err(dev, "wrong response buffer."); rc = -ENODATA; goto cleanup; } msg->resp.len = min_t(unsigned int, len, sizeof(msg->resp.data)); rc = 0; cleanup: if (rc) { /* Clean the virtqueue. */ while (virtqueue_get_buf(vq, &len) != NULL) ; } return rc; } static int fill_req_get_random(struct nsm *nsm, struct nsm_data_req *req) { /* * 69 # text(9) * 47657452616E646F6D # "GetRandom" */ const u8 request[] = { CBOR_TYPE_TEXT + strlen("GetRandom"), 'G', 'e', 't', 'R', 'a', 'n', 'd', 'o', 'm' }; memcpy(req->data, request, sizeof(request)); req->len = sizeof(request); return 0; } static int parse_resp_get_random(struct nsm *nsm, struct nsm_data_resp *resp, void *out, size_t max) { /* * A1 # map(1) * 69 # text(9) - Name of field * 47657452616E646F6D # "GetRandom" * A1 # map(1) - The field itself * 66 # text(6) * 72616E646F6D # "random" * # The rest of the response is random data */ const u8 response[] = { CBOR_TYPE_MAP + 1, CBOR_TYPE_TEXT + strlen("GetRandom"), 'G', 'e', 't', 'R', 'a', 'n', 'd', 'o', 'm', CBOR_TYPE_MAP + 1, CBOR_TYPE_TEXT + strlen("random"), 'r', 'a', 'n', 'd', 'o', 'm' }; struct device *dev = &nsm->vdev->dev; u8 *rand_data = NULL; u8 *resp_ptr = resp->data; u64 resp_len = resp->len; int rc; if ((resp->len < sizeof(response) + 1) || (memcmp(resp_ptr, response, sizeof(response)) != 0)) { dev_err(dev, "Invalid response for GetRandom"); return -EFAULT; } resp_ptr += sizeof(response); resp_len -= sizeof(response); rc = cbor_object_get_array(resp_ptr, resp_len, &rand_data); if (rc < 0) { dev_err(dev, "GetRandom: Invalid CBOR encoding\n"); return rc; } rc = min_t(size_t, rc, max); memcpy(out, rand_data, rc); return rc; } /* * HwRNG implementation */ static int nsm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) { struct nsm *nsm = hwrng_to_nsm(rng); struct device *dev = &nsm->vdev->dev; int rc = 0; /* NSM always needs to wait for a response */ if (!wait) return 0; mutex_lock(&nsm->lock); rc = fill_req_get_random(nsm, &nsm->msg.req); if (rc != 0) goto out; rc = nsm_sendrecv_msg_locked(nsm); if (rc != 0) goto out; rc = parse_resp_get_random(nsm, &nsm->msg.resp, data, max); if (rc < 0) goto out; dev_dbg(dev, "RNG: returning rand bytes = %d", rc); out: mutex_unlock(&nsm->lock); return rc; } static long nsm_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = u64_to_user_ptr((u64)arg); struct nsm *nsm = file_to_nsm(file); struct nsm_raw raw; int r = 0; if (cmd != NSM_IOCTL_RAW) return -EINVAL; if (_IOC_SIZE(cmd) != sizeof(raw)) return -EINVAL; /* Copy user argument struct to kernel argument struct */ if (copy_from_user(&raw, argp, _IOC_SIZE(cmd))) return -EFAULT; mutex_lock(&nsm->lock); /* Convert kernel argument struct to device request */ r = fill_req_raw(nsm, &nsm->msg.req, &raw); if (r) goto out; /* Send message to NSM and read reply */ r = nsm_sendrecv_msg_locked(nsm); if (r) goto out; /* Parse device response into kernel argument struct */ r = parse_resp_raw(nsm, &nsm->msg.resp, &raw); if (r) goto out; /* Copy kernel argument struct back to user argument struct */ r = -EFAULT; if (copy_to_user(argp, &raw, sizeof(raw))) goto out; r = 0; out: mutex_unlock(&nsm->lock); return r; } static int nsm_device_init_vq(struct virtio_device *vdev) { struct virtqueue *vq = virtio_find_single_vq(vdev, nsm_vq_callback, "nsm.vq.0"); struct nsm *nsm = vdev->priv; if (IS_ERR(vq)) return PTR_ERR(vq); nsm->vq = vq; return 0; } static const struct file_operations nsm_dev_fops = { .owner = THIS_MODULE, .unlocked_ioctl = nsm_dev_ioctl, .compat_ioctl = compat_ptr_ioctl, }; /* Handler for probing the NSM device */ static int nsm_device_probe(struct virtio_device *vdev) { struct device *dev = &vdev->dev; struct nsm *nsm; int rc; nsm = devm_kzalloc(&vdev->dev, sizeof(*nsm), GFP_KERNEL); if (!nsm) return -ENOMEM; vdev->priv = nsm; nsm->vdev = vdev; rc = nsm_device_init_vq(vdev); if (rc) { dev_err(dev, "queue failed to initialize: %d.\n", rc); goto err_init_vq; } mutex_init(&nsm->lock); /* Register as hwrng provider */ nsm->hwrng = (struct hwrng) { .read = nsm_rng_read, .name = "nsm-hwrng", .quality = 1000, }; rc = hwrng_register(&nsm->hwrng); if (rc) { dev_err(dev, "RNG initialization error: %d.\n", rc); goto err_hwrng; } /* Register /dev/nsm device node */ nsm->misc = (struct miscdevice) { .minor = MISC_DYNAMIC_MINOR, .name = "nsm", .fops = &nsm_dev_fops, .mode = 0666, }; rc = misc_register(&nsm->misc); if (rc) { dev_err(dev, "misc device registration error: %d.\n", rc); goto err_misc; } return 0; err_misc: hwrng_unregister(&nsm->hwrng); err_hwrng: vdev->config->del_vqs(vdev); err_init_vq: return rc; } /* Handler for removing the NSM device */ static void nsm_device_remove(struct virtio_device *vdev) { struct nsm *nsm = vdev->priv; hwrng_unregister(&nsm->hwrng); vdev->config->del_vqs(vdev); misc_deregister(&nsm->misc); } /* NSM device configuration structure */ static struct virtio_driver virtio_nsm_driver = { .feature_table = 0, .feature_table_size = 0, .feature_table_legacy = 0, .feature_table_size_legacy = 0, .driver.name = KBUILD_MODNAME, .id_table = id_table, .probe = nsm_device_probe, .remove = nsm_device_remove, };