virtio-rng: hardware random number generator device
The Linux kernel already has a virtio-rng driver, this is the device
implementation.
When the guest asks for entropy from the virtio hwrng, it puts a buffer
in the vq. We then put entropy into that buffer, and push it back to
the guest.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
aliguori: converted to new RngBackend interface
aliguori: remove entropy needed event
aliguori: fix migration
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index af4ab0c..ea46f81 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -1,6 +1,7 @@
common-obj-y = usb/ ide/
common-obj-y += loader.o
common-obj-$(CONFIG_VIRTIO) += virtio-console.o
+common-obj-$(CONFIG_VIRTIO) += virtio-rng.o
common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
common-obj-y += fw_cfg.o
common-obj-$(CONFIG_PCI) += pci.o pci_bridge.o pci_bridge_dev.o
diff --git a/hw/pci.h b/hw/pci.h
index 241c1d8..4da0c2a 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -76,6 +76,7 @@
#define PCI_DEVICE_ID_VIRTIO_BALLOON 0x1002
#define PCI_DEVICE_ID_VIRTIO_CONSOLE 0x1003
#define PCI_DEVICE_ID_VIRTIO_SCSI 0x1004
+#define PCI_DEVICE_ID_VIRTIO_RNG 0x1005
#define FMT_PCIBUS PRIx64
diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c
index 5849a96..e0ac2d1 100644
--- a/hw/s390-virtio-bus.c
+++ b/hw/s390-virtio-bus.c
@@ -26,6 +26,7 @@
#include "loader.h"
#include "elf.h"
#include "hw/virtio.h"
+#include "hw/virtio-rng.h"
#include "hw/virtio-serial.h"
#include "hw/virtio-net.h"
#include "hw/sysbus.h"
@@ -206,6 +207,18 @@
return s390_virtio_device_init(dev, vdev);
}
+static int s390_virtio_rng_init(VirtIOS390Device *dev)
+{
+ VirtIODevice *vdev;
+
+ vdev = virtio_rng_init((DeviceState *)dev, &dev->rng);
+ if (!vdev) {
+ return -1;
+ }
+
+ return s390_virtio_device_init(dev, vdev);
+}
+
static uint64_t s390_virtio_device_vq_token(VirtIOS390Device *dev, int vq)
{
ram_addr_t token_off;
@@ -448,6 +461,29 @@
.class_init = s390_virtio_serial_class_init,
};
+static void s390_virtio_rng_initfn(Object *obj)
+{
+ VirtIOS390Device *dev = VIRTIO_S390_DEVICE(obj);
+
+ object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
+ (Object **)&dev->rng.rng, NULL);
+}
+
+static void s390_virtio_rng_class_init(ObjectClass *klass, void *data)
+{
+ VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
+
+ k->init = s390_virtio_rng_init;
+}
+
+static TypeInfo s390_virtio_rng = {
+ .name = "virtio-rng-s390",
+ .parent = TYPE_VIRTIO_S390_DEVICE,
+ .instance_size = sizeof(VirtIOS390Device),
+ .instance_init = s390_virtio_rng_initfn,
+ .class_init = s390_virtio_rng_class_init,
+};
+
static int s390_virtio_busdev_init(DeviceState *dev)
{
VirtIOS390Device *_dev = (VirtIOS390Device *)dev;
@@ -528,6 +564,7 @@
type_register_static(&s390_virtio_blk);
type_register_static(&s390_virtio_net);
type_register_static(&s390_virtio_scsi);
+ type_register_static(&s390_virtio_rng);
type_register_static(&s390_virtio_bridge_info);
}
diff --git a/hw/s390-virtio-bus.h b/hw/s390-virtio-bus.h
index 4873134..a83afe7 100644
--- a/hw/s390-virtio-bus.h
+++ b/hw/s390-virtio-bus.h
@@ -19,6 +19,7 @@
#include "virtio-blk.h"
#include "virtio-net.h"
+#include "virtio-rng.h"
#include "virtio-serial.h"
#include "virtio-scsi.h"
@@ -75,6 +76,7 @@
virtio_serial_conf serial;
virtio_net_conf net;
VirtIOSCSIConf scsi;
+ VirtIORNGConf rng;
};
typedef struct VirtIOS390Bus {
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 9603150..a3d4777 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -852,6 +852,28 @@
virtio_exit_pci(pci_dev);
}
+static int virtio_rng_init_pci(PCIDevice *pci_dev)
+{
+ VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+ VirtIODevice *vdev;
+
+ vdev = virtio_rng_init(&pci_dev->qdev, &proxy->rng);
+ if (!vdev) {
+ return -1;
+ }
+ virtio_init_pci(proxy, vdev);
+ return 0;
+}
+
+static void virtio_rng_exit_pci(PCIDevice *pci_dev)
+{
+ VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+
+ virtio_pci_stop_ioeventfd(proxy);
+ virtio_rng_exit(proxy->vdev);
+ virtio_exit_pci(pci_dev);
+}
+
static Property virtio_blk_properties[] = {
DEFINE_PROP_HEX32("class", VirtIOPCIProxy, class_code, 0),
DEFINE_BLOCK_PROPERTIES(VirtIOPCIProxy, blk.conf),
@@ -982,6 +1004,43 @@
.class_init = virtio_balloon_class_init,
};
+static void virtio_rng_initfn(Object *obj)
+{
+ PCIDevice *pci_dev = PCI_DEVICE(obj);
+ VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+
+ object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
+ (Object **)&proxy->rng.rng, NULL);
+}
+
+static Property virtio_rng_properties[] = {
+ DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_rng_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+ k->init = virtio_rng_init_pci;
+ k->exit = virtio_rng_exit_pci;
+ k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+ k->device_id = PCI_DEVICE_ID_VIRTIO_RNG;
+ k->revision = VIRTIO_PCI_ABI_VERSION;
+ k->class_id = PCI_CLASS_OTHERS;
+ dc->reset = virtio_pci_reset;
+ dc->props = virtio_rng_properties;
+}
+
+static TypeInfo virtio_rng_info = {
+ .name = "virtio-rng-pci",
+ .parent = TYPE_PCI_DEVICE,
+ .instance_size = sizeof(VirtIOPCIProxy),
+ .instance_init = virtio_rng_initfn,
+ .class_init = virtio_rng_class_init,
+};
+
static int virtio_scsi_init_pci(PCIDevice *pci_dev)
{
VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
@@ -1046,6 +1105,7 @@
type_register_static(&virtio_serial_info);
type_register_static(&virtio_balloon_info);
type_register_static(&virtio_scsi_info);
+ type_register_static(&virtio_rng_info);
}
type_init(virtio_pci_register_types)
diff --git a/hw/virtio-pci.h b/hw/virtio-pci.h
index ac9d522..b58d9a2 100644
--- a/hw/virtio-pci.h
+++ b/hw/virtio-pci.h
@@ -17,6 +17,7 @@
#include "virtio-blk.h"
#include "virtio-net.h"
+#include "virtio-rng.h"
#include "virtio-serial.h"
#include "virtio-scsi.h"
@@ -46,6 +47,7 @@
virtio_serial_conf serial;
virtio_net_conf net;
VirtIOSCSIConf scsi;
+ VirtIORNGConf rng;
bool ioeventfd_disabled;
bool ioeventfd_started;
VirtIOIRQFD *vector_irqfd;
diff --git a/hw/virtio-rng.c b/hw/virtio-rng.c
new file mode 100644
index 0000000..b7fb5e9
--- /dev/null
+++ b/hw/virtio-rng.c
@@ -0,0 +1,211 @@
+/*
+ * 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 "iov.h"
+#include "qdev.h"
+#include "virtio.h"
+#include "virtio-rng.h"
+#include "qemu/rng.h"
+
+typedef struct VirtIORNG {
+ VirtIODevice vdev;
+
+ DeviceState *qdev;
+
+ /* Only one vq - guest puts buffer(s) on it when it needs entropy */
+ VirtQueue *vq;
+ VirtQueueElement elem;
+
+ /* Config data for the device -- currently only chardev */
+ VirtIORNGConf *conf;
+
+ /* Whether we've popped a vq element into 'elem' above */
+ bool popped;
+
+ RngBackend *rng;
+} VirtIORNG;
+
+static bool is_guest_ready(VirtIORNG *vrng)
+{
+ if (virtio_queue_ready(vrng->vq)
+ && (vrng->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+ return true;
+ }
+ return false;
+}
+
+static size_t pop_an_elem(VirtIORNG *vrng)
+{
+ size_t size;
+
+ if (!vrng->popped && !virtqueue_pop(vrng->vq, &vrng->elem)) {
+ return 0;
+ }
+ vrng->popped = true;
+
+ size = iov_size(vrng->elem.in_sg, vrng->elem.in_num);
+ return size;
+}
+
+/* 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;
+ size_t len;
+ int offset;
+
+ if (!is_guest_ready(vrng)) {
+ return;
+ }
+
+ offset = 0;
+ while (offset < size) {
+ if (!pop_an_elem(vrng)) {
+ break;
+ }
+ len = iov_from_buf(vrng->elem.in_sg, vrng->elem.in_num,
+ 0, buf + offset, size - offset);
+ offset += len;
+
+ virtqueue_push(vrng->vq, &vrng->elem, len);
+ vrng->popped = false;
+ }
+ virtio_notify(&vrng->vdev, vrng->vq);
+
+ /*
+ * Lastly, if we had multiple elems queued by the guest, and we
+ * didn't have enough data to fill them all, indicate we want more
+ * data.
+ */
+ len = pop_an_elem(vrng);
+ if (len) {
+ rng_backend_request_entropy(vrng->rng, size, chr_read, vrng);
+ }
+}
+
+static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIORNG *vrng = DO_UPCAST(VirtIORNG, vdev, vdev);
+ size_t size;
+
+ size = pop_an_elem(vrng);
+ if (size) {
+ rng_backend_request_entropy(vrng->rng, size, chr_read, vrng);
+ }
+}
+
+static uint32_t get_features(VirtIODevice *vdev, uint32_t f)
+{
+ return f;
+}
+
+static void virtio_rng_save(QEMUFile *f, void *opaque)
+{
+ VirtIORNG *vrng = opaque;
+
+ virtio_save(&vrng->vdev, f);
+
+ qemu_put_byte(f, vrng->popped);
+ if (vrng->popped) {
+ int i;
+
+ qemu_put_be32(f, vrng->elem.index);
+
+ qemu_put_be32(f, vrng->elem.in_num);
+ for (i = 0; i < vrng->elem.in_num; i++) {
+ qemu_put_be64(f, vrng->elem.in_addr[i]);
+ }
+
+ qemu_put_be32(f, vrng->elem.out_num);
+ for (i = 0; i < vrng->elem.out_num; i++) {
+ qemu_put_be64(f, vrng->elem.out_addr[i]);
+ }
+ }
+}
+
+static int virtio_rng_load(QEMUFile *f, void *opaque, int version_id)
+{
+ VirtIORNG *vrng = opaque;
+
+ if (version_id != 1) {
+ return -EINVAL;
+ }
+ virtio_load(&vrng->vdev, f);
+
+ vrng->popped = qemu_get_byte(f);
+ if (vrng->popped) {
+ int i;
+
+ vrng->elem.index = qemu_get_be32(f);
+
+ vrng->elem.in_num = qemu_get_be32(f);
+ g_assert(vrng->elem.in_num < VIRTQUEUE_MAX_SIZE);
+ for (i = 0; i < vrng->elem.in_num; i++) {
+ vrng->elem.in_addr[i] = qemu_get_be64(f);
+ }
+
+ vrng->elem.out_num = qemu_get_be32(f);
+ g_assert(vrng->elem.out_num < VIRTQUEUE_MAX_SIZE);
+ for (i = 0; i < vrng->elem.out_num; i++) {
+ vrng->elem.out_addr[i] = qemu_get_be64(f);
+ }
+
+ virtqueue_map_sg(vrng->elem.in_sg, vrng->elem.in_addr,
+ vrng->elem.in_num, 1);
+ virtqueue_map_sg(vrng->elem.out_sg, vrng->elem.out_addr,
+ vrng->elem.out_num, 0);
+ }
+ return 0;
+}
+
+VirtIODevice *virtio_rng_init(DeviceState *dev, VirtIORNGConf *conf)
+{
+ VirtIORNG *vrng;
+ VirtIODevice *vdev;
+ 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;
+ }
+
+ rng_backend_open(vrng->rng, &local_err);
+ if (local_err) {
+ qerror_report_err(local_err);
+ error_free(local_err);
+ return NULL;
+ }
+
+ vrng->vq = virtio_add_queue(vdev, 8, handle_input);
+ vrng->vdev.get_features = get_features;
+
+ vrng->qdev = dev;
+ vrng->conf = conf;
+ vrng->popped = false;
+ register_savevm(dev, "virtio-rng", -1, 1, virtio_rng_save,
+ virtio_rng_load, vrng);
+
+ return vdev;
+}
+
+void virtio_rng_exit(VirtIODevice *vdev)
+{
+ VirtIORNG *vrng = DO_UPCAST(VirtIORNG, vdev, vdev);
+
+ unregister_savevm(vrng->qdev, "virtio-rng", vrng);
+ virtio_cleanup(vdev);
+}
diff --git a/hw/virtio-rng.h b/hw/virtio-rng.h
new file mode 100644
index 0000000..fbb0104
--- /dev/null
+++ b/hw/virtio-rng.h
@@ -0,0 +1,24 @@
+/*
+ * Virtio RNG Support
+ *
+ * Copyright Red Hat, Inc. 2012
+ * Copyright 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.
+ */
+
+#ifndef _QEMU_VIRTIO_RNG_H
+#define _QEMU_VIRTIO_RNG_H
+
+#include "qemu/rng.h"
+
+/* The Virtio ID for the virtio rng device */
+#define VIRTIO_ID_RNG 4
+
+struct VirtIORNGConf {
+ RngBackend *rng;
+};
+
+#endif
diff --git a/hw/virtio.h b/hw/virtio.h
index ac482be..df8d0f7 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -203,6 +203,8 @@
VirtIODevice *virtio_balloon_init(DeviceState *dev);
typedef struct VirtIOSCSIConf VirtIOSCSIConf;
VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *conf);
+typedef struct VirtIORNGConf VirtIORNGConf;
+VirtIODevice *virtio_rng_init(DeviceState *dev, VirtIORNGConf *conf);
#ifdef CONFIG_LINUX
VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf);
#endif
@@ -213,6 +215,7 @@
void virtio_serial_exit(VirtIODevice *vdev);
void virtio_balloon_exit(VirtIODevice *vdev);
void virtio_scsi_exit(VirtIODevice *vdev);
+void virtio_rng_exit(VirtIODevice *vdev);
#define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
DEFINE_PROP_BIT("indirect_desc", _state, _field, \
