X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/47b5264eb3e1cd2825e48d28fd0d1b239ed53974..f93caaac36ec3b030184055596cb56f64d0de988:/hw/virtio/virtio-rng.c diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c index 6079b2a3a9..97d1541918 100644 --- a/hw/virtio/virtio-rng.c +++ b/hw/virtio/virtio-rng.c @@ -11,17 +11,20 @@ #include "qemu/iov.h" #include "hw/qdev.h" -#include "qapi/qmp/qerror.h" #include "hw/virtio/virtio.h" #include "hw/virtio/virtio-rng.h" -#include "qemu/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) - && (vrng->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) { + && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) { return true; } + trace_virtio_rng_guest_not_ready(vrng); return false; } @@ -39,6 +42,7 @@ static void virtio_rng_process(VirtIORNG *vrng); 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; @@ -59,8 +63,9 @@ static void chr_read(void *opaque, const void *buf, size_t size) offset += len; virtqueue_push(vrng->vq, &elem, len); + trace_virtio_rng_pushed(vrng, len); } - virtio_notify(&vrng->vdev, vrng->vq); + virtio_notify(vdev, vrng->vq); } static void virtio_rng_process(VirtIORNG *vrng) @@ -72,12 +77,21 @@ static void virtio_rng_process(VirtIORNG *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); @@ -86,30 +100,34 @@ static void virtio_rng_process(VirtIORNG *vrng) static void handle_input(VirtIODevice *vdev, VirtQueue *vq) { - VirtIORNG *vrng = DO_UPCAST(VirtIORNG, vdev, vdev); + VirtIORNG *vrng = VIRTIO_RNG(vdev); virtio_rng_process(vrng); } -static uint32_t get_features(VirtIODevice *vdev, uint32_t f) +static uint64_t get_features(VirtIODevice *vdev, uint64_t f, Error **errp) { return f; } static void virtio_rng_save(QEMUFile *f, void *opaque) { - VirtIORNG *vrng = opaque; + VirtIODevice *vdev = opaque; - virtio_save(&vrng->vdev, f); + 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; } - virtio_load(&vrng->vdev, f); + 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 @@ -122,66 +140,128 @@ static int virtio_rng_load(QEMUFile *f, void *opaque, int version_id) static void check_rate_limit(void *opaque) { - VirtIORNG *s = opaque; + VirtIORNG *vrng = opaque; - s->quota_remaining = s->conf->max_bytes; - virtio_rng_process(s); - qemu_mod_timer(s->rate_limit_timer, - qemu_get_clock_ms(vm_clock) + s->conf->period_ms); + vrng->quota_remaining = vrng->conf.max_bytes; + virtio_rng_process(vrng); + vrng->activate_timer = true; } - -VirtIODevice *virtio_rng_init(DeviceState *dev, VirtIORNGConf *conf) +static void virtio_rng_device_realize(DeviceState *dev, Error **errp) { - VirtIORNG *vrng; - VirtIODevice *vdev; + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VirtIORNG *vrng = VIRTIO_RNG(dev); Error *local_err = NULL; - vdev = virtio_common_init("virtio-rng", VIRTIO_ID_RNG, 0, - sizeof(VirtIORNG)); - - vrng = DO_UPCAST(VirtIORNG, vdev, vdev); - - vrng->rng = conf->rng; - if (vrng->rng == NULL) { - qerror_report(QERR_INVALID_PARAMETER_VALUE, "rng", "a valid object"); - return NULL; + if (vrng->conf.period_ms <= 0) { + error_setg(errp, "'period' parameter expects a positive integer"); + return; } - rng_backend_open(vrng->rng, &local_err); - if (local_err) { - qerror_report_err(local_err); - error_free(local_err); - return NULL; + /* 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; } - vrng->vq = virtio_add_queue(vdev, 8, handle_input); - vrng->vdev.get_features = get_features; + if (vrng->conf.rng == NULL) { + vrng->conf.default_backend = RNG_RANDOM(object_new(TYPE_RNG_RANDOM)); - vrng->qdev = dev; - vrng->conf = conf; + 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; + } - assert(vrng->conf->max_bytes <= INT64_MAX); - vrng->quota_remaining = vrng->conf->max_bytes; + object_property_add_child(OBJECT(dev), + "default-backend", + OBJECT(vrng->conf.default_backend), + NULL); - vrng->rate_limit_timer = qemu_new_timer_ms(vm_clock, - check_rate_limit, vrng); + /* 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; + } - qemu_mod_timer(vrng->rate_limit_timer, - qemu_get_clock_ms(vm_clock) + vrng->conf->period_ms); + 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); - - return vdev; } -void virtio_rng_exit(VirtIODevice *vdev) +static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp) { - VirtIORNG *vrng = DO_UPCAST(VirtIORNG, vdev, vdev); + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VirtIORNG *vrng = VIRTIO_RNG(dev); - qemu_del_timer(vrng->rate_limit_timer); - qemu_free_timer(vrng->rate_limit_timer); - unregister_savevm(vrng->qdev, "virtio-rng", vrng); + 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)