From 16c915ba42b45df7a64a6908287f03bfa3764bed Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Wed, 20 Jun 2012 12:29:32 +0530 Subject: [PATCH] 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 Signed-off-by: Anthony Liguori --- aliguori: converted to new RngBackend interface aliguori: remove entropy needed event aliguori: fix migration --- hw/Makefile.objs | 1 + hw/pci.h | 1 + hw/s390-virtio-bus.c | 37 ++++++++ hw/s390-virtio-bus.h | 2 + hw/virtio-pci.c | 60 ++++++++++++ hw/virtio-pci.h | 2 + hw/virtio-rng.c | 211 +++++++++++++++++++++++++++++++++++++++++++ hw/virtio-rng.h | 24 +++++ hw/virtio.h | 3 + 9 files changed, 341 insertions(+) create mode 100644 hw/virtio-rng.c create mode 100644 hw/virtio-rng.h diff --git a/hw/Makefile.objs b/hw/Makefile.objs index af4ab0c735..ea46f8128e 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 241c1d8905..4da0c2a4c9 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 5849a964a4..e0ac2d1ec2 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 @@ static int s390_virtio_scsi_init(VirtIOS390Device *dev) 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 @@ static TypeInfo s390_virtio_serial = { .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 @@ static void s390_virtio_register_types(void) 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 4873134ae9..a83afe785f 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 @@ struct VirtIOS390Device { 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 96031500ee..a3d4777e8d 100644 --- a/hw/virtio-pci.c +++ b/hw/virtio-pci.c @@ -852,6 +852,28 @@ static void virtio_balloon_exit_pci(PCIDevice *pci_dev) 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 @@ static TypeInfo virtio_balloon_info = { .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 @@ static void virtio_pci_register_types(void) 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 ac9d522f37..b58d9a2d19 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 @@ typedef struct { 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 0000000000..b7fb5e9d61 --- /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 + * + * 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 0000000000..fbb01048ba --- /dev/null +++ b/hw/virtio-rng.h @@ -0,0 +1,24 @@ +/* + * Virtio RNG Support + * + * Copyright Red Hat, Inc. 2012 + * Copyright Amit Shah + * + * 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 ac482be24c..df8d0f7b69 100644 --- a/hw/virtio.h +++ b/hw/virtio.h @@ -203,6 +203,8 @@ VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *serial); 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_blk_exit(VirtIODevice *vdev); 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, \