https://github.com/torvalds/linux
Tip revision: 6d796c50f84ca79f1722bb131799e5a5710c4700 authored by Linus Torvalds on 29 January 2023, 21:59:43 UTC
Linux 6.2-rc6
Linux 6.2-rc6
Tip revision: 6d796c5
virtio_test.c
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <getopt.h>
#include <limits.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 <stdbool.h>
#include <linux/virtio_types.h>
#include <linux/vhost.h>
#include <linux/virtio.h>
#include <linux/virtio_ring.h>
#include "../../drivers/vhost/test.h"
#define RANDOM_BATCH -1
/* Unused */
void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
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;
};
static const struct vhost_vring_file no_backend = { .fd = -1 },
backend = { .fd = 1 };
static const struct vhost_vring_state null_state = {};
bool 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);
return true;
}
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;
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_reset(struct vq_info *info, int num, struct virtio_device *vdev)
{
if (info->vq)
vring_del_virtqueue(info->vq);
memset(info->ring, 0, vring_size(num, 4096));
vring_init(&info->vring, num, info->ring, 4096);
info->vq = vring_new_virtqueue(info->idx, num, 4096, vdev, true, false,
info->ring, vq_notify, vq_callback, "test");
assert(info->vq);
info->vq->priv = info;
}
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);
vq_reset(info, num, &dev->vdev);
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 = features;
INIT_LIST_HEAD(&dev->vdev.vqs);
spin_lock_init(&dev->vdev.vqs_list_lock);
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,
bool delayed, int batch, int reset_n, int bufs)
{
struct scatterlist sl;
long started = 0, completed = 0, next_reset = reset_n;
long completed_before, started_before;
int r, test = 1;
unsigned int len;
long long spurious = 0;
const bool random_batch = batch == RANDOM_BATCH;
r = ioctl(dev->control, VHOST_TEST_RUN, &test);
assert(r >= 0);
if (!reset_n) {
next_reset = INT_MAX;
}
for (;;) {
virtqueue_disable_cb(vq->vq);
completed_before = completed;
started_before = started;
do {
const bool reset = completed > next_reset;
if (random_batch)
batch = (random() % vq->vring.num) + 1;
while (started < bufs &&
(started - completed) < batch) {
sg_init_one(&sl, dev->buf, dev->buf_size);
r = virtqueue_add_outbuf(vq->vq, &sl, 1,
dev->buf + started,
GFP_ATOMIC);
if (unlikely(r != 0)) {
if (r == -ENOSPC &&
started > started_before)
r = 0;
else
r = -1;
break;
}
++started;
if (unlikely(!virtqueue_kick(vq->vq))) {
r = -1;
break;
}
}
if (started >= bufs)
r = -1;
if (reset) {
r = ioctl(dev->control, VHOST_TEST_SET_BACKEND,
&no_backend);
assert(!r);
}
/* Flush out completed bufs if any */
while (virtqueue_get_buf(vq->vq, &len)) {
++completed;
r = 0;
}
if (reset) {
struct vhost_vring_state s = { .index = 0 };
vq_reset(vq, vq->vring.num, &dev->vdev);
r = ioctl(dev->control, VHOST_GET_VRING_BASE,
&s);
assert(!r);
s.num = 0;
r = ioctl(dev->control, VHOST_SET_VRING_BASE,
&null_state);
assert(!r);
r = ioctl(dev->control, VHOST_TEST_SET_BACKEND,
&backend);
assert(!r);
started = completed;
while (completed > next_reset)
next_reset += completed;
}
} while (r == 0);
if (completed == completed_before && started == started_before)
++spurious;
assert(completed <= bufs);
assert(started <= bufs);
if (completed == bufs)
break;
if (delayed) {
if (virtqueue_enable_cb_delayed(vq->vq))
wait_for_interrupt(dev);
} else {
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 wakeups: 0x%llx started=0x%lx completed=0x%lx\n",
spurious, started, completed);
}
const char optstring[] = "h";
const struct option longopts[] = {
{
.name = "help",
.val = 'h',
},
{
.name = "event-idx",
.val = 'E',
},
{
.name = "no-event-idx",
.val = 'e',
},
{
.name = "indirect",
.val = 'I',
},
{
.name = "no-indirect",
.val = 'i',
},
{
.name = "virtio-1",
.val = '1',
},
{
.name = "no-virtio-1",
.val = '0',
},
{
.name = "delayed-interrupt",
.val = 'D',
},
{
.name = "no-delayed-interrupt",
.val = 'd',
},
{
.name = "batch",
.val = 'b',
.has_arg = required_argument,
},
{
.name = "reset",
.val = 'r',
.has_arg = optional_argument,
},
{
}
};
static void help(void)
{
fprintf(stderr, "Usage: virtio_test [--help]"
" [--no-indirect]"
" [--no-event-idx]"
" [--no-virtio-1]"
" [--delayed-interrupt]"
" [--batch=random/N]"
" [--reset=N]"
"\n");
}
int main(int argc, char **argv)
{
struct vdev_info dev;
unsigned long long features = (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
(1ULL << VIRTIO_RING_F_EVENT_IDX) | (1ULL << VIRTIO_F_VERSION_1);
long batch = 1, reset = 0;
int o;
bool delayed = false;
for (;;) {
o = getopt_long(argc, argv, optstring, longopts, NULL);
switch (o) {
case -1:
goto done;
case '?':
help();
exit(2);
case 'e':
features &= ~(1ULL << VIRTIO_RING_F_EVENT_IDX);
break;
case 'h':
help();
goto done;
case 'i':
features &= ~(1ULL << VIRTIO_RING_F_INDIRECT_DESC);
break;
case '0':
features &= ~(1ULL << VIRTIO_F_VERSION_1);
break;
case 'D':
delayed = true;
break;
case 'b':
if (0 == strcmp(optarg, "random")) {
batch = RANDOM_BATCH;
} else {
batch = strtol(optarg, NULL, 10);
assert(batch > 0);
assert(batch < (long)INT_MAX + 1);
}
break;
case 'r':
if (!optarg) {
reset = 1;
} else {
reset = strtol(optarg, NULL, 10);
assert(reset > 0);
assert(reset < (long)INT_MAX + 1);
}
break;
default:
assert(0);
break;
}
}
done:
vdev_info_init(&dev, features);
vq_info_add(&dev, 256);
run_test(&dev, &dev.vqs[0], delayed, batch, reset, 0x100000);
return 0;
}