tools/virtio: virtio_test tool
This is the userspace part of the tool: it includes a bunch of stubs for
linux APIs, somewhat simular to linuxsched. This makes it possible to
recompile the ring code in userspace.
A small test example is implemented combining this with vhost_test
module.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
new file mode 100644
index 0000000..df0c6d2
--- /dev/null
+++ b/tools/virtio/virtio_test.c
@@ -0,0 +1,248 @@
+#define _GNU_SOURCE
+#include <getopt.h>
+#include <string.h>
+#include <poll.h>
+#include <sys/eventfd.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <linux/vhost.h>
+#include <linux/virtio.h>
+#include <linux/virtio_ring.h>
+#include "../../drivers/vhost/test.h"
+
+struct vq_info {
+ int kick;
+ int call;
+ int num;
+ int idx;
+ void *ring;
+ /* copy used for control */
+ struct vring vring;
+ struct virtqueue *vq;
+};
+
+struct vdev_info {
+ struct virtio_device vdev;
+ int control;
+ struct pollfd fds[1];
+ struct vq_info vqs[1];
+ int nvqs;
+ void *buf;
+ size_t buf_size;
+ struct vhost_memory *mem;
+};
+
+void vq_notify(struct virtqueue *vq)
+{
+ struct vq_info *info = vq->priv;
+ unsigned long long v = 1;
+ int r;
+ r = write(info->kick, &v, sizeof v);
+ assert(r == sizeof v);
+}
+
+void vq_callback(struct virtqueue *vq)
+{
+}
+
+
+void vhost_vq_setup(struct vdev_info *dev, struct vq_info *info)
+{
+ struct vhost_vring_state state = { .index = info->idx };
+ struct vhost_vring_file file = { .index = info->idx };
+ unsigned long long features = dev->vdev.features[0];
+ struct vhost_vring_addr addr = {
+ .index = info->idx,
+ .desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
+ .avail_user_addr = (uint64_t)(unsigned long)info->vring.avail,
+ .used_user_addr = (uint64_t)(unsigned long)info->vring.used,
+ };
+ int r;
+ r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
+ assert(r >= 0);
+ state.num = info->vring.num;
+ r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
+ assert(r >= 0);
+ state.num = 0;
+ r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
+ assert(r >= 0);
+ r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
+ assert(r >= 0);
+ file.fd = info->kick;
+ r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
+ assert(r >= 0);
+ file.fd = info->call;
+ r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
+ assert(r >= 0);
+}
+
+static void vq_info_add(struct vdev_info *dev, int num)
+{
+ struct vq_info *info = &dev->vqs[dev->nvqs];
+ int r;
+ info->idx = dev->nvqs;
+ info->kick = eventfd(0, EFD_NONBLOCK);
+ info->call = eventfd(0, EFD_NONBLOCK);
+ r = posix_memalign(&info->ring, 4096, vring_size(num, 4096));
+ assert(r >= 0);
+ memset(info->ring, 0, vring_size(num, 4096));
+ vring_init(&info->vring, num, info->ring, 4096);
+ info->vq = vring_new_virtqueue(info->vring.num, 4096, &dev->vdev, info->ring,
+ vq_notify, vq_callback, "test");
+ assert(info->vq);
+ info->vq->priv = info;
+ vhost_vq_setup(dev, info);
+ dev->fds[info->idx].fd = info->call;
+ dev->fds[info->idx].events = POLLIN;
+ dev->nvqs++;
+}
+
+static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
+{
+ int r;
+ memset(dev, 0, sizeof *dev);
+ dev->vdev.features[0] = features;
+ dev->vdev.features[1] = features >> 32;
+ dev->buf_size = 1024;
+ dev->buf = malloc(dev->buf_size);
+ assert(dev->buf);
+ dev->control = open("/dev/vhost-test", O_RDWR);
+ assert(dev->control >= 0);
+ r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
+ assert(r >= 0);
+ dev->mem = malloc(offsetof(struct vhost_memory, regions) +
+ sizeof dev->mem->regions[0]);
+ assert(dev->mem);
+ memset(dev->mem, 0, offsetof(struct vhost_memory, regions) +
+ sizeof dev->mem->regions[0]);
+ dev->mem->nregions = 1;
+ dev->mem->regions[0].guest_phys_addr = (long)dev->buf;
+ dev->mem->regions[0].userspace_addr = (long)dev->buf;
+ dev->mem->regions[0].memory_size = dev->buf_size;
+ r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
+ assert(r >= 0);
+}
+
+/* TODO: this is pretty bad: we get a cache line bounce
+ * for the wait queue on poll and another one on read,
+ * plus the read which is there just to clear the
+ * current state. */
+static void wait_for_interrupt(struct vdev_info *dev)
+{
+ int i;
+ unsigned long long val;
+ poll(dev->fds, dev->nvqs, -1);
+ for (i = 0; i < dev->nvqs; ++i)
+ if (dev->fds[i].revents & POLLIN) {
+ read(dev->fds[i].fd, &val, sizeof val);
+ }
+}
+
+static void run_test(struct vdev_info *dev, struct vq_info *vq, int bufs)
+{
+ struct scatterlist sl;
+ long started = 0, completed = 0;
+ long completed_before;
+ int r, test = 1;
+ unsigned len;
+ long long spurious = 0;
+ r = ioctl(dev->control, VHOST_TEST_RUN, &test);
+ assert(r >= 0);
+ for (;;) {
+ virtqueue_disable_cb(vq->vq);
+ completed_before = completed;
+ do {
+ if (started < bufs) {
+ sg_init_one(&sl, dev->buf, dev->buf_size);
+ r = virtqueue_add_buf(vq->vq, &sl, 1, 0,
+ dev->buf + started);
+ if (likely(r >= 0)) {
+ ++started;
+ virtqueue_kick(vq->vq);
+ }
+ } else
+ r = -1;
+
+ /* Flush out completed bufs if any */
+ if (virtqueue_get_buf(vq->vq, &len)) {
+ ++completed;
+ r = 0;
+ }
+
+ } while (r >= 0);
+ if (completed == completed_before)
+ ++spurious;
+ assert(completed <= bufs);
+ assert(started <= bufs);
+ if (completed == bufs)
+ break;
+ if (virtqueue_enable_cb(vq->vq)) {
+ wait_for_interrupt(dev);
+ }
+ }
+ test = 0;
+ r = ioctl(dev->control, VHOST_TEST_RUN, &test);
+ assert(r >= 0);
+ fprintf(stderr, "spurious wakeus: 0x%llx\n", spurious);
+}
+
+const char optstring[] = "h";
+const struct option longopts[] = {
+ {
+ .name = "help",
+ .val = 'h',
+ },
+ {
+ .name = "indirect",
+ .val = 'I',
+ },
+ {
+ .name = "no-indirect",
+ .val = 'i',
+ },
+ {
+ }
+};
+
+static void help()
+{
+ fprintf(stderr, "Usage: virtio_test [--help] [--no-indirect]\n");
+}
+
+int main(int argc, char **argv)
+{
+ struct vdev_info dev;
+ unsigned long long features = 1ULL << VIRTIO_RING_F_INDIRECT_DESC;
+ int o;
+
+ for (;;) {
+ o = getopt_long(argc, argv, optstring, longopts, NULL);
+ switch (o) {
+ case -1:
+ goto done;
+ case '?':
+ help();
+ exit(2);
+ case 'h':
+ help();
+ goto done;
+ case 'i':
+ features &= ~(1ULL << VIRTIO_RING_F_INDIRECT_DESC);
+ break;
+ default:
+ assert(0);
+ break;
+ }
+ }
+
+done:
+ vdev_info_init(&dev, features);
+ vq_info_add(&dev, 256);
+ run_test(&dev, &dev.vqs[0], 0x100000);
+ return 0;
+}