Adding upstream version 1:7.2+dfsg.upstream/1%7.2+dfsgupstream

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 289 insertions, 0 deletions

diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
new file mode 100644
index 00000000..7e12fc03
--- /dev/null
+++ b/hw/virtio/virtio-rng.c
@@ -0,0 +1,289 @@
+/*
+ * 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 "qemu/module.h"
+#include "qemu/timer.h"
+#include "hw/virtio/virtio.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/virtio-rng.h"
+#include "sysemu/rng.h"
+#include "sysemu/runstate.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;
+    }
+
+    /* we can't modify the virtqueue until
+     * our state is fully synced
+     */
+
+    if (!runstate_check(RUN_STATE_RUNNING)) {
+        trace_virtio_rng_cpu_is_stopped(vrng, size);
+        return;
+    }
+
+    vrng->quota_remaining -= size;
+
+    offset = 0;
+    while (offset < size) {
+        elem = virtqueue_pop(vrng->vq, sizeof(VirtQueueElement));
+        if (!elem) {
+            break;
+        }
+        trace_virtio_rng_popped(vrng);
+        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_vm_state_change(void *opaque, bool running,
+                                       RunState state)
+{
+    VirtIORNG *vrng = opaque;
+
+    trace_virtio_rng_vm_state_change(vrng, running, state);
+
+    /* We may have an element ready but couldn't process it due to a quota
+     * limit or because CPU was stopped.  Make sure to try again when the
+     * CPU restart.
+     */
+
+    if (running && is_guest_ready(vrng)) {
+        virtio_rng_process(vrng);
+    }
+}
+
+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_set_status(VirtIODevice *vdev, uint8_t status)
+{
+    VirtIORNG *vrng = VIRTIO_RNG(vdev);
+
+    if (!vdev->vm_running) {
+        return;
+    }
+    vdev->status = status;
+
+    /* Something changed, try to process buffers */
+    virtio_rng_process(vrng);
+}
+
+static void virtio_rng_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIORNG *vrng = VIRTIO_RNG(dev);
+
+    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) {
+        Object *default_backend = object_new(TYPE_RNG_BUILTIN);
+
+        if (!user_creatable_complete(USER_CREATABLE(default_backend),
+                                     errp)) {
+            object_unref(default_backend);
+            return;
+        }
+
+        object_property_add_child(OBJECT(dev), "default-backend",
+                                  default_backend);
+
+        /* The child property took a reference, we can safely drop ours now */
+        object_unref(default_backend);
+
+        object_property_set_link(OBJECT(dev), "rng", default_backend,
+                                 &error_abort);
+    }
+
+    vrng->rng = vrng->conf.rng;
+    if (vrng->rng == NULL) {
+        error_setg(errp, "'rng' parameter expects a valid object");
+        return;
+    }
+
+    virtio_init(vdev, 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;
+
+    vrng->vmstate = qemu_add_vm_change_state_handler(virtio_rng_vm_state_change,
+                                                     vrng);
+}
+
+static void virtio_rng_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIORNG *vrng = VIRTIO_RNG(dev);
+
+    qemu_del_vm_change_state_handler(vrng->vmstate);
+    timer_free(vrng->rate_limit_timer);
+    virtio_del_queue(vdev, 0);
+    virtio_cleanup(vdev);
+}
+
+static const VMStateDescription vmstate_virtio_rng = {
+    .name = "virtio-rng",
+    .minimum_version_id = 1,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_VIRTIO_DEVICE,
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+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_LINK("rng", VirtIORNG, conf.rng, TYPE_RNG_BACKEND, RngBackend *),
+    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);
+
+    device_class_set_props(dc, virtio_rng_properties);
+    dc->vmsd = &vmstate_virtio_rng;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    vdc->realize = virtio_rng_device_realize;
+    vdc->unrealize = virtio_rng_device_unrealize;
+    vdc->get_features = get_features;
+    vdc->set_status = virtio_rng_set_status;
+}
+
+static const TypeInfo virtio_rng_info = {
+    .name = TYPE_VIRTIO_RNG,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VirtIORNG),
+    .class_init = virtio_rng_class_init,
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&virtio_rng_info);
+}
+
+type_init(virtio_register_types)