kvm tools: Introduce virtio-rng

Enable virtio-rng, a virtio random number generator.
Guest kernel should be compiled with CONFIG_HW_RANDOM_VIRTIO.
Once enabled, A RNG device will be located at /dev/hwrng.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
index 659bc351cabcfca51f2b95865c58a4b74ecfa63e..19e7b9e6f7c9d17b7988b418045e159a71a543fc 100644 (file)
--- a/tools/kvm/Makefile
+++ b/tools/kvm/Makefile
@@ -38,6 +38,7 @@ OBJS    += kvm-run.o
 OBJS    += qcow.o
 OBJS    += mptable.o
 OBJS    += threadpool.o
+OBJS    += virtio-rng.o
 
 DEPS   := $(patsubst %.o,%.d,$(OBJS))
 

diff --git a/tools/kvm/include/kvm/ioport.h b/tools/kvm/include/kvm/ioport.h
index 2fdcca459fa4a0f1c43d2c6d51495110c789de34..60201245a38137af299601068b3600e9530e90ef 100644 (file)
--- a/tools/kvm/include/kvm/ioport.h
+++ b/tools/kvm/include/kvm/ioport.h
@@ -12,6 +12,8 @@
 #define IOPORT_VIRTIO_CONSOLE_SIZE     256
 #define IOPORT_VIRTIO_NET              0xe200  /* Virtio network device */
 #define IOPORT_VIRTIO_NET_SIZE         256
+#define IOPORT_VIRTIO_RNG              0xf200  /* Virtio network device */
+#define IOPORT_VIRTIO_RNG_SIZE         256
 
 struct kvm;
 

diff --git a/tools/kvm/include/kvm/virtio-rng.h b/tools/kvm/include/kvm/virtio-rng.h
new file mode 100644 (file)
index 0000000..7015c1f
--- /dev/null
+++ b/tools/kvm/include/kvm/virtio-rng.h
@@ -0,0 +1,8 @@
+#ifndef KVM__RNG_VIRTIO_H
+#define KVM__RNG_VIRTIO_H
+
+struct kvm;
+
+void virtio_rng__init(struct kvm *kvm);
+
+#endif /* KVM__RNG_VIRTIO_H */

diff --git a/tools/kvm/virtio-rng.c b/tools/kvm/virtio-rng.c
new file mode 100644 (file)
index 0000000..4cec97d
--- /dev/null
+++ b/tools/kvm/virtio-rng.c
@@ -0,0 +1,184 @@
+#include "kvm/virtio-rng.h"
+
+#include "kvm/virtio-pci.h"
+
+#include "kvm/disk-image.h"
+#include "kvm/virtio.h"
+#include "kvm/ioport.h"
+#include "kvm/mutex.h"
+#include "kvm/util.h"
+#include "kvm/kvm.h"
+#include "kvm/pci.h"
+#include "kvm/threadpool.h"
+
+#include <linux/virtio_ring.h>
+#include <linux/virtio_rng.h>
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <inttypes.h>
+#include <pthread.h>
+
+#define PCI_VENDOR_ID_REDHAT_QUMRANET                  0x1af4
+#define PCI_DEVICE_ID_VIRTIO_RNG                               0x1004
+#define PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET        0x1af4
+#define PCI_SUBSYSTEM_ID_VIRTIO_RNG                            0x0004
+#define PCI_VIRTIO_RNG_DEVNUM 4
+
+#define VIRTIO_RNG_IRQ         11
+#define VIRTIO_RNG_PIN         1
+
+#define NUM_VIRT_QUEUES                1
+
+#define VIRTIO_RNG_QUEUE_SIZE  128
+
+struct rng_device {
+       uint8_t                         status;
+       uint16_t                        config_vector;
+       int                                     fd_rng;
+
+       /* virtio queue */
+       uint16_t                        queue_selector;
+       struct virt_queue       vqs[NUM_VIRT_QUEUES];
+       void                            *jobs[NUM_VIRT_QUEUES];
+};
+
+static struct rng_device rng_device;
+
+static bool virtio_rng_pci_io_in(struct kvm *kvm, uint16_t port, void *data, int size, uint32_t count)
+{
+       unsigned long offset;
+       bool ret = true;
+
+       offset = port - IOPORT_VIRTIO_RNG;
+
+       switch (offset) {
+       case VIRTIO_PCI_HOST_FEATURES:
+       case VIRTIO_PCI_GUEST_FEATURES:
+       case VIRTIO_PCI_QUEUE_SEL:
+       case VIRTIO_PCI_QUEUE_NOTIFY:
+               ret             = false;
+               break;
+       case VIRTIO_PCI_QUEUE_PFN:
+               ioport__write32(data, rng_device.vqs[rng_device.queue_selector].pfn);
+               break;
+       case VIRTIO_PCI_QUEUE_NUM:
+               ioport__write16(data, VIRTIO_RNG_QUEUE_SIZE);
+               break;
+       case VIRTIO_PCI_STATUS:
+               ioport__write8(data, rng_device.status);
+               break;
+       case VIRTIO_PCI_ISR:
+               ioport__write8(data, 0x1);
+               kvm__irq_line(kvm, VIRTIO_RNG_IRQ, 0);
+               break;
+       case VIRTIO_MSI_CONFIG_VECTOR:
+               ioport__write16(data, rng_device.config_vector);
+               break;
+       default:
+               ret             = false;
+       };
+
+       return ret;
+}
+
+static bool virtio_rng_do_io_request(struct kvm *self, struct virt_queue *queue)
+{
+       struct iovec iov[VIRTIO_RNG_QUEUE_SIZE];
+       uint16_t out, in, head;
+       unsigned int len = 0;
+
+       head = virt_queue__get_iov(queue, iov, &out, &in, self);
+       len = readv(rng_device.fd_rng, iov, in);
+       virt_queue__set_used_elem(queue, head, len);
+
+       return true;
+}
+
+static void virtio_rng_do_io(struct kvm *kvm, void *param)
+{
+       struct virt_queue *vq = param;
+
+       while (virt_queue__available(vq)) {
+               virtio_rng_do_io_request(kvm, vq);
+               kvm__irq_line(kvm, VIRTIO_RNG_IRQ, 1);
+       }
+}
+
+static bool virtio_rng_pci_io_out(struct kvm *kvm, uint16_t port, void *data, int size, uint32_t count)
+{
+       unsigned long offset;
+       bool ret = true;
+
+       offset = port - IOPORT_VIRTIO_RNG;
+
+       switch (offset) {
+       case VIRTIO_MSI_QUEUE_VECTOR:
+       case VIRTIO_PCI_GUEST_FEATURES:
+               break;
+       case VIRTIO_PCI_QUEUE_PFN: {
+               struct virt_queue *queue;
+               void *p;
+
+               queue                   = &rng_device.vqs[rng_device.queue_selector];
+               queue->pfn              = ioport__read32(data);
+               p                               = guest_flat_to_host(kvm, queue->pfn << 12);
+
+               vring_init(&queue->vring, VIRTIO_RNG_QUEUE_SIZE, p, 4096);
+
+               rng_device.jobs[rng_device.queue_selector] =
+                       thread_pool__add_jobtype(kvm, virtio_rng_do_io, queue);
+
+               break;
+       }
+       case VIRTIO_PCI_QUEUE_SEL:
+               rng_device.queue_selector       = ioport__read16(data);
+               break;
+       case VIRTIO_PCI_QUEUE_NOTIFY: {
+               uint16_t queue_index;
+               queue_index             = ioport__read16(data);
+               thread_pool__signal_work(rng_device.jobs[queue_index]);
+               break;
+       }
+       case VIRTIO_PCI_STATUS:
+               rng_device.status               = ioport__read8(data);
+               break;
+       case VIRTIO_MSI_CONFIG_VECTOR:
+               rng_device.config_vector        = VIRTIO_MSI_NO_VECTOR;
+               break;
+       default:
+               ret             = false;
+       };
+
+       return ret;
+}
+
+static struct ioport_operations virtio_rng_io_ops = {
+       .io_in          = virtio_rng_pci_io_in,
+       .io_out         = virtio_rng_pci_io_out,
+};
+
+static struct pci_device_header virtio_rng_pci_device = {
+       .vendor_id                      = PCI_VENDOR_ID_REDHAT_QUMRANET,
+       .device_id                      = PCI_DEVICE_ID_VIRTIO_RNG,
+       .header_type            = PCI_HEADER_TYPE_NORMAL,
+       .revision_id            = 0,
+       .class                          = 0x010000,
+       .subsys_vendor_id       = PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET,
+       .subsys_id                      = PCI_SUBSYSTEM_ID_VIRTIO_RNG,
+       .bar[0]                         = IOPORT_VIRTIO_RNG | PCI_BASE_ADDRESS_SPACE_IO,
+       .irq_pin                        = VIRTIO_RNG_PIN,
+       .irq_line                       = VIRTIO_RNG_IRQ,
+};
+
+void virtio_rng__init(struct kvm *kvm)
+{
+       rng_device.fd_rng = open("/dev/urandom", O_RDONLY);
+       if (rng_device.fd_rng < 0)
+               die("Failed initializing RNG");
+
+       pci__register(&virtio_rng_pci_device, PCI_VIRTIO_RNG_DEVNUM);
+
+       ioport__register(IOPORT_VIRTIO_RNG, &virtio_rng_io_ops, IOPORT_VIRTIO_RNG_SIZE);
+}