diff options
Diffstat (limited to 'qemu/hw/virtio/virtio-rng.c')
| -rw-r--r-- | qemu/hw/virtio/virtio-rng.c | 278 |
1 files changed, 0 insertions, 278 deletions
diff --git a/qemu/hw/virtio/virtio-rng.c b/qemu/hw/virtio/virtio-rng.c deleted file mode 100644 index 6b991a764..000000000 --- a/qemu/hw/virtio/virtio-rng.c +++ /dev/null @@ -1,278 +0,0 @@ -/* - * A virtio device implementing a hardware random number generator. - * - * Copyright 2012 Red Hat, Inc. - * Copyright 2012 Amit Shah <amit.shah@redhat.com> - * - * This work is licensed under the terms of the GNU GPL, version 2 or - * (at your option) any later version. See the COPYING file in the - * top-level directory. - */ - -#include "qemu/osdep.h" -#include "qapi/error.h" -#include "qemu/iov.h" -#include "hw/qdev.h" -#include "hw/virtio/virtio.h" -#include "hw/virtio/virtio-rng.h" -#include "sysemu/rng.h" -#include "qom/object_interfaces.h" -#include "trace.h" - -static bool is_guest_ready(VirtIORNG *vrng) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(vrng); - if (virtio_queue_ready(vrng->vq) - && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) { - return true; - } - trace_virtio_rng_guest_not_ready(vrng); - return false; -} - -static size_t get_request_size(VirtQueue *vq, unsigned quota) -{ - unsigned int in, out; - - virtqueue_get_avail_bytes(vq, &in, &out, quota, 0); - return in; -} - -static void virtio_rng_process(VirtIORNG *vrng); - -/* Send data from a char device over to the guest */ -static void chr_read(void *opaque, const void *buf, size_t size) -{ - VirtIORNG *vrng = opaque; - VirtIODevice *vdev = VIRTIO_DEVICE(vrng); - VirtQueueElement *elem; - size_t len; - int offset; - - if (!is_guest_ready(vrng)) { - return; - } - - vrng->quota_remaining -= size; - - offset = 0; - while (offset < size) { - elem = virtqueue_pop(vrng->vq, sizeof(VirtQueueElement)); - if (!elem) { - break; - } - len = iov_from_buf(elem->in_sg, elem->in_num, - 0, buf + offset, size - offset); - offset += len; - - virtqueue_push(vrng->vq, elem, len); - trace_virtio_rng_pushed(vrng, len); - g_free(elem); - } - virtio_notify(vdev, vrng->vq); - - if (!virtio_queue_empty(vrng->vq)) { - /* If we didn't drain the queue, call virtio_rng_process - * to take care of asking for more data as appropriate. - */ - virtio_rng_process(vrng); - } -} - -static void virtio_rng_process(VirtIORNG *vrng) -{ - size_t size; - unsigned quota; - - if (!is_guest_ready(vrng)) { - return; - } - - if (vrng->activate_timer) { - timer_mod(vrng->rate_limit_timer, - qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vrng->conf.period_ms); - vrng->activate_timer = false; - } - - if (vrng->quota_remaining < 0) { - quota = 0; - } else { - quota = MIN((uint64_t)vrng->quota_remaining, (uint64_t)UINT32_MAX); - } - size = get_request_size(vrng->vq, quota); - - trace_virtio_rng_request(vrng, size, quota); - - size = MIN(vrng->quota_remaining, size); - if (size) { - rng_backend_request_entropy(vrng->rng, size, chr_read, vrng); - } -} - -static void handle_input(VirtIODevice *vdev, VirtQueue *vq) -{ - VirtIORNG *vrng = VIRTIO_RNG(vdev); - virtio_rng_process(vrng); -} - -static uint64_t get_features(VirtIODevice *vdev, uint64_t f, Error **errp) -{ - return f; -} - -static void virtio_rng_save(QEMUFile *f, void *opaque) -{ - VirtIODevice *vdev = opaque; - - virtio_save(vdev, f); -} - -static int virtio_rng_load(QEMUFile *f, void *opaque, int version_id) -{ - VirtIORNG *vrng = opaque; - int ret; - - if (version_id != 1) { - return -EINVAL; - } - ret = virtio_load(VIRTIO_DEVICE(vrng), f, version_id); - if (ret != 0) { - return ret; - } - - /* We may have an element ready but couldn't process it due to a quota - * limit. Make sure to try again after live migration when the quota may - * have been reset. - */ - virtio_rng_process(vrng); - - return 0; -} - -static void check_rate_limit(void *opaque) -{ - VirtIORNG *vrng = opaque; - - vrng->quota_remaining = vrng->conf.max_bytes; - virtio_rng_process(vrng); - vrng->activate_timer = true; -} - -static void virtio_rng_device_realize(DeviceState *dev, Error **errp) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(dev); - VirtIORNG *vrng = VIRTIO_RNG(dev); - Error *local_err = NULL; - - if (vrng->conf.period_ms <= 0) { - error_setg(errp, "'period' parameter expects a positive integer"); - return; - } - - /* Workaround: Property parsing does not enforce unsigned integers, - * So this is a hack to reject such numbers. */ - if (vrng->conf.max_bytes > INT64_MAX) { - error_setg(errp, "'max-bytes' parameter must be non-negative, " - "and less than 2^63"); - return; - } - - if (vrng->conf.rng == NULL) { - vrng->conf.default_backend = RNG_RANDOM(object_new(TYPE_RNG_RANDOM)); - - user_creatable_complete(OBJECT(vrng->conf.default_backend), - &local_err); - if (local_err) { - error_propagate(errp, local_err); - object_unref(OBJECT(vrng->conf.default_backend)); - return; - } - - object_property_add_child(OBJECT(dev), - "default-backend", - OBJECT(vrng->conf.default_backend), - NULL); - - /* The child property took a reference, we can safely drop ours now */ - object_unref(OBJECT(vrng->conf.default_backend)); - - object_property_set_link(OBJECT(dev), - OBJECT(vrng->conf.default_backend), - "rng", NULL); - } - - vrng->rng = vrng->conf.rng; - if (vrng->rng == NULL) { - error_setg(errp, "'rng' parameter expects a valid object"); - return; - } - - virtio_init(vdev, "virtio-rng", VIRTIO_ID_RNG, 0); - - vrng->vq = virtio_add_queue(vdev, 8, handle_input); - vrng->quota_remaining = vrng->conf.max_bytes; - vrng->rate_limit_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, - check_rate_limit, vrng); - vrng->activate_timer = true; - register_savevm(dev, "virtio-rng", -1, 1, virtio_rng_save, - virtio_rng_load, vrng); -} - -static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(dev); - VirtIORNG *vrng = VIRTIO_RNG(dev); - - timer_del(vrng->rate_limit_timer); - timer_free(vrng->rate_limit_timer); - unregister_savevm(dev, "virtio-rng", vrng); - virtio_cleanup(vdev); -} - -static Property virtio_rng_properties[] = { - /* Set a default rate limit of 2^47 bytes per minute or roughly 2TB/s. If - * you have an entropy source capable of generating more entropy than this - * and you can pass it through via virtio-rng, then hats off to you. Until - * then, this is unlimited for all practical purposes. - */ - DEFINE_PROP_UINT64("max-bytes", VirtIORNG, conf.max_bytes, INT64_MAX), - DEFINE_PROP_UINT32("period", VirtIORNG, conf.period_ms, 1 << 16), - DEFINE_PROP_END_OF_LIST(), -}; - -static void virtio_rng_class_init(ObjectClass *klass, void *data) -{ - DeviceClass *dc = DEVICE_CLASS(klass); - VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); - - dc->props = virtio_rng_properties; - set_bit(DEVICE_CATEGORY_MISC, dc->categories); - vdc->realize = virtio_rng_device_realize; - vdc->unrealize = virtio_rng_device_unrealize; - vdc->get_features = get_features; -} - -static void virtio_rng_initfn(Object *obj) -{ - VirtIORNG *vrng = VIRTIO_RNG(obj); - - object_property_add_link(obj, "rng", TYPE_RNG_BACKEND, - (Object **)&vrng->conf.rng, - qdev_prop_allow_set_link_before_realize, - OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL); -} - -static const TypeInfo virtio_rng_info = { - .name = TYPE_VIRTIO_RNG, - .parent = TYPE_VIRTIO_DEVICE, - .instance_size = sizeof(VirtIORNG), - .instance_init = virtio_rng_initfn, - .class_init = virtio_rng_class_init, -}; - -static void virtio_register_types(void) -{ - type_register_static(&virtio_rng_info); -} - -type_init(virtio_register_types) |