tools/virtio/vringh_test.c
// SPDX-License-Identifier: GPL-2.0
/* Simple test of virtio code, entirely in userpsace. */
#define _GNU_SOURCE
#include <sched.h>
#include <err.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/virtio.h>
#include <linux/vringh.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_config.h>
#include <linux/uaccess.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <fcntl.h>
#define USER_MEM (1024*1024)
void *__user_addr_min, *__user_addr_max;
void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
static u64 user_addr_offset;
#define RINGSIZE 256
#define ALIGN 4096
static bool never_notify_host(struct virtqueue *vq)
{
abort();
}
static void never_callback_guest(struct virtqueue *vq)
{
abort();
}
static bool getrange_iov(struct vringh *vrh, u64 addr, struct vringh_range *r)
{
if (addr < (u64)(unsigned long)__user_addr_min - user_addr_offset)
return false;
if (addr >= (u64)(unsigned long)__user_addr_max - user_addr_offset)
return false;
r->start = (u64)(unsigned long)__user_addr_min - user_addr_offset;
r->end_incl = (u64)(unsigned long)__user_addr_max - 1 - user_addr_offset;
r->offset = user_addr_offset;
return true;
}
/* We return single byte ranges. */
static bool getrange_slow(struct vringh *vrh, u64 addr, struct vringh_range *r)
{
if (addr < (u64)(unsigned long)__user_addr_min - user_addr_offset)
return false;
if (addr >= (u64)(unsigned long)__user_addr_max - user_addr_offset)
return false;
r->start = addr;
r->end_incl = r->start;
r->offset = user_addr_offset;
return true;
}
struct guest_virtio_device {
struct virtio_device vdev;
int to_host_fd;
unsigned long notifies;
};
static bool parallel_notify_host(struct virtqueue *vq)
{
int rc;
struct guest_virtio_device *gvdev;
gvdev = container_of(vq->vdev, struct guest_virtio_device, vdev);
rc = write(gvdev->to_host_fd, "", 1);
if (rc < 0)
return false;
gvdev->notifies++;
return true;
}
static bool no_notify_host(struct virtqueue *vq)
{
return true;
}
#define NUM_XFERS (10000000)
/* We aim for two "distant" cpus. */
static void find_cpus(unsigned int *first, unsigned int *last)
{
unsigned int i;
*first = -1U;
*last = 0;
for (i = 0; i < 4096; i++) {
cpu_set_t set;
CPU_ZERO(&set);
CPU_SET(i, &set);
if (sched_setaffinity(getpid(), sizeof(set), &set) == 0) {
if (i < *first)
*first = i;
if (i > *last)
*last = i;
}
}
}
/* Opencoded version for fast mode */
static inline int vringh_get_head(struct vringh *vrh, u16 *head)
{
u16 avail_idx, i;
int err;
err = get_user(avail_idx, &vrh->vring.avail->idx);
if (err)
return err;
if (vrh->last_avail_idx == avail_idx)
return 0;
/* Only get avail ring entries after they have been exposed by guest. */
virtio_rmb(vrh->weak_barriers);
i = vrh->last_avail_idx & (vrh->vring.num - 1);
err = get_user(*head, &vrh->vring.avail->ring[i]);
if (err)
return err;
vrh->last_avail_idx++;
return 1;
}
static int parallel_test(u64 features,
bool (*getrange)(struct vringh *vrh,
u64 addr, struct vringh_range *r),
bool fast_vringh)
{
void *host_map, *guest_map;
int fd, mapsize, to_guest[2], to_host[2];
unsigned long xfers = 0, notifies = 0, receives = 0;
unsigned int first_cpu, last_cpu;
cpu_set_t cpu_set;
char buf[128];
/* Create real file to mmap. */
fd = open("/tmp/vringh_test-file", O_RDWR|O_CREAT|O_TRUNC, 0600);
if (fd < 0)
err(1, "Opening /tmp/vringh_test-file");
/* Extra room at the end for some data, and indirects */
mapsize = vring_size(RINGSIZE, ALIGN)
+ RINGSIZE * 2 * sizeof(int)
+ RINGSIZE * 6 * sizeof(struct vring_desc);
mapsize = (mapsize + getpagesize() - 1) & ~(getpagesize() - 1);
ftruncate(fd, mapsize);
/* Parent and child use separate addresses, to check our mapping logic! */
host_map = mmap(NULL, mapsize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
guest_map = mmap(NULL, mapsize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
pipe(to_guest);
pipe(to_host);
CPU_ZERO(&cpu_set);
find_cpus(&first_cpu, &last_cpu);
printf("Using CPUS %u and %u\n", first_cpu, last_cpu);
fflush(stdout);
if (fork() != 0) {
struct vringh vrh;
int status, err, rlen = 0;
char rbuf[5];
/* We are the host: never access guest addresses! */
munmap(guest_map, mapsize);
__user_addr_min = host_map;
__user_addr_max = __user_addr_min + mapsize;
user_addr_offset = host_map - guest_map;
assert(user_addr_offset);
close(to_guest[0]);
close(to_host[1]);
vring_init(&vrh.vring, RINGSIZE, host_map, ALIGN);
vringh_init_user(&vrh, features, RINGSIZE, true,
vrh.vring.desc, vrh.vring.avail, vrh.vring.used);
CPU_SET(first_cpu, &cpu_set);
if (sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set))
errx(1, "Could not set affinity to cpu %u", first_cpu);
while (xfers < NUM_XFERS) {
struct iovec host_riov[2], host_wiov[2];
struct vringh_iov riov, wiov;
u16 head, written;
if (fast_vringh) {
for (;;) {
err = vringh_get_head(&vrh, &head);
if (err != 0)
break;
err = vringh_need_notify_user(&vrh);
if (err < 0)
errx(1, "vringh_need_notify_user: %i",
err);
if (err) {
write(to_guest[1], "", 1);
notifies++;
}
}
if (err != 1)
errx(1, "vringh_get_head");
written = 0;
goto complete;
} else {
vringh_iov_init(&riov,
host_riov,
ARRAY_SIZE(host_riov));
vringh_iov_init(&wiov,
host_wiov,
ARRAY_SIZE(host_wiov));
err = vringh_getdesc_user(&vrh, &riov, &wiov,
getrange, &head);
}
if (err == 0) {
err = vringh_need_notify_user(&vrh);
if (err < 0)
errx(1, "vringh_need_notify_user: %i",
err);
if (err) {
write(to_guest[1], "", 1);
notifies++;
}
if (!vringh_notify_enable_user(&vrh))
continue;
/* Swallow all notifies at once. */
if (read(to_host[0], buf, sizeof(buf)) < 1)
break;
vringh_notify_disable_user(&vrh);
receives++;
continue;
}
if (err != 1)
errx(1, "vringh_getdesc_user: %i", err);
/* We simply copy bytes. */
if (riov.used) {
rlen = vringh_iov_pull_user(&riov, rbuf,
sizeof(rbuf));
if (rlen != 4)
errx(1, "vringh_iov_pull_user: %i",
rlen);
assert(riov.i == riov.used);
written = 0;
} else {
err = vringh_iov_push_user(&wiov, rbuf, rlen);
if (err != rlen)
errx(1, "vringh_iov_push_user: %i",
err);
assert(wiov.i == wiov.used);
written = err;
}
complete:
xfers++;
err = vringh_complete_user(&vrh, head, written);
if (err != 0)
errx(1, "vringh_complete_user: %i", err);
}
err = vringh_need_notify_user(&vrh);
if (err < 0)
errx(1, "vringh_need_notify_user: %i", err);
if (err) {
write(to_guest[1], "", 1);
notifies++;
}
wait(&status);
if (!WIFEXITED(status))
errx(1, "Child died with signal %i?", WTERMSIG(status));
if (WEXITSTATUS(status) != 0)
errx(1, "Child exited %i?", WEXITSTATUS(status));
printf("Host: notified %lu, pinged %lu\n", notifies, receives);
return 0;
} else {
struct guest_virtio_device gvdev;
struct virtqueue *vq;
unsigned int *data;
struct vring_desc *indirects;
unsigned int finished = 0;
/* We pass sg[]s pointing into here, but we need RINGSIZE+1 */
data = guest_map + vring_size(RINGSIZE, ALIGN);
indirects = (void *)data + (RINGSIZE + 1) * 2 * sizeof(int);
/* We are the guest. */
munmap(host_map, mapsize);
close(to_guest[1]);
close(to_host[0]);
gvdev.vdev.features = features;
INIT_LIST_HEAD(&gvdev.vdev.vqs);
spin_lock_init(&gvdev.vdev.vqs_list_lock);
gvdev.to_host_fd = to_host[1];
gvdev.notifies = 0;
CPU_SET(first_cpu, &cpu_set);
if (sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set))
err(1, "Could not set affinity to cpu %u", first_cpu);
vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &gvdev.vdev, true,
false, guest_map,
fast_vringh ? no_notify_host
: parallel_notify_host,
never_callback_guest, "guest vq");
/* Don't kfree indirects. */
__kfree_ignore_start = indirects;
__kfree_ignore_end = indirects + RINGSIZE * 6;
while (xfers < NUM_XFERS) {
struct scatterlist sg[4];
unsigned int num_sg, len;
int *dbuf, err;
bool output = !(xfers % 2);
/* Consume bufs. */
while ((dbuf = virtqueue_get_buf(vq, &len)) != NULL) {
if (len == 4)
assert(*dbuf == finished - 1);
else if (!fast_vringh)
assert(*dbuf == finished);
finished++;
}
/* Produce a buffer. */
dbuf = data + (xfers % (RINGSIZE + 1));
if (output)
*dbuf = xfers;
else
*dbuf = -1;
switch ((xfers / sizeof(*dbuf)) % 4) {
case 0:
/* Nasty three-element sg list. */
sg_init_table(sg, num_sg = 3);
sg_set_buf(&sg[0], (void *)dbuf, 1);
sg_set_buf(&sg[1], (void *)dbuf + 1, 2);
sg_set_buf(&sg[2], (void *)dbuf + 3, 1);
break;
case 1:
sg_init_table(sg, num_sg = 2);
sg_set_buf(&sg[0], (void *)dbuf, 1);
sg_set_buf(&sg[1], (void *)dbuf + 1, 3);
break;
case 2:
sg_init_table(sg, num_sg = 1);
sg_set_buf(&sg[0], (void *)dbuf, 4);
break;
case 3:
sg_init_table(sg, num_sg = 4);
sg_set_buf(&sg[0], (void *)dbuf, 1);
sg_set_buf(&sg[1], (void *)dbuf + 1, 1);
sg_set_buf(&sg[2], (void *)dbuf + 2, 1);
sg_set_buf(&sg[3], (void *)dbuf + 3, 1);
break;
}
/* May allocate an indirect, so force it to allocate
* user addr */
__kmalloc_fake = indirects + (xfers % RINGSIZE) * 4;
if (output)
err = virtqueue_add_outbuf(vq, sg, num_sg, dbuf,
GFP_KERNEL);
else
err = virtqueue_add_inbuf(vq, sg, num_sg,
dbuf, GFP_KERNEL);
if (err == -ENOSPC) {
if (!virtqueue_enable_cb_delayed(vq))
continue;
/* Swallow all notifies at once. */
if (read(to_guest[0], buf, sizeof(buf)) < 1)
break;
receives++;
virtqueue_disable_cb(vq);
continue;
}
if (err)
errx(1, "virtqueue_add_in/outbuf: %i", err);
xfers++;
virtqueue_kick(vq);
}
/* Any extra? */
while (finished != xfers) {
int *dbuf;
unsigned int len;
/* Consume bufs. */
dbuf = virtqueue_get_buf(vq, &len);
if (dbuf) {
if (len == 4)
assert(*dbuf == finished - 1);
else
assert(len == 0);
finished++;
continue;
}
if (!virtqueue_enable_cb_delayed(vq))
continue;
if (read(to_guest[0], buf, sizeof(buf)) < 1)
break;
receives++;
virtqueue_disable_cb(vq);
}
printf("Guest: notified %lu, pinged %lu\n",
gvdev.notifies, receives);
vring_del_virtqueue(vq);
return 0;
}
}
int main(int argc, char *argv[])
{
struct virtio_device vdev;
struct virtqueue *vq;
struct vringh vrh;
struct scatterlist guest_sg[RINGSIZE], *sgs[2];
struct iovec host_riov[2], host_wiov[2];
struct vringh_iov riov, wiov;
struct vring_used_elem used[RINGSIZE];
char buf[28];
u16 head;
int err;
unsigned i;
void *ret;
bool (*getrange)(struct vringh *vrh, u64 addr, struct vringh_range *r);
bool fast_vringh = false, parallel = false;
getrange = getrange_iov;
vdev.features = 0;
INIT_LIST_HEAD(&vdev.vqs);
spin_lock_init(&vdev.vqs_list_lock);
while (argv[1]) {
if (strcmp(argv[1], "--indirect") == 0)
__virtio_set_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC);
else if (strcmp(argv[1], "--eventidx") == 0)
__virtio_set_bit(&vdev, VIRTIO_RING_F_EVENT_IDX);
else if (strcmp(argv[1], "--virtio-1") == 0)
__virtio_set_bit(&vdev, VIRTIO_F_VERSION_1);
else if (strcmp(argv[1], "--slow-range") == 0)
getrange = getrange_slow;
else if (strcmp(argv[1], "--fast-vringh") == 0)
fast_vringh = true;
else if (strcmp(argv[1], "--parallel") == 0)
parallel = true;
else
errx(1, "Unknown arg %s", argv[1]);
argv++;
}
if (parallel)
return parallel_test(vdev.features, getrange, fast_vringh);
if (posix_memalign(&__user_addr_min, PAGE_SIZE, USER_MEM) != 0)
abort();
__user_addr_max = __user_addr_min + USER_MEM;
memset(__user_addr_min, 0, vring_size(RINGSIZE, ALIGN));
/* Set up guest side. */
vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &vdev, true, false,
__user_addr_min,
never_notify_host, never_callback_guest,
"guest vq");
/* Set up host side. */
vring_init(&vrh.vring, RINGSIZE, __user_addr_min, ALIGN);
vringh_init_user(&vrh, vdev.features, RINGSIZE, true,
vrh.vring.desc, vrh.vring.avail, vrh.vring.used);
/* No descriptor to get yet... */
err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
if (err != 0)
errx(1, "vringh_getdesc_user: %i", err);
/* Guest puts in a descriptor. */
memcpy(__user_addr_max - 1, "a", 1);
sg_init_table(guest_sg, 1);
sg_set_buf(&guest_sg[0], __user_addr_max - 1, 1);
sg_init_table(guest_sg+1, 1);
sg_set_buf(&guest_sg[1], __user_addr_max - 3, 2);
sgs[0] = &guest_sg[0];
sgs[1] = &guest_sg[1];
/* May allocate an indirect, so force it to allocate user addr */
__kmalloc_fake = __user_addr_min + vring_size(RINGSIZE, ALIGN);
err = virtqueue_add_sgs(vq, sgs, 1, 1, &err, GFP_KERNEL);
if (err)
errx(1, "virtqueue_add_sgs: %i", err);
__kmalloc_fake = NULL;
/* Host retreives it. */
vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
if (err != 1)
errx(1, "vringh_getdesc_user: %i", err);
assert(riov.used == 1);
assert(riov.iov[0].iov_base == __user_addr_max - 1);
assert(riov.iov[0].iov_len == 1);
if (getrange != getrange_slow) {
assert(wiov.used == 1);
assert(wiov.iov[0].iov_base == __user_addr_max - 3);
assert(wiov.iov[0].iov_len == 2);
} else {
assert(wiov.used == 2);
assert(wiov.iov[0].iov_base == __user_addr_max - 3);
assert(wiov.iov[0].iov_len == 1);
assert(wiov.iov[1].iov_base == __user_addr_max - 2);
assert(wiov.iov[1].iov_len == 1);
}
err = vringh_iov_pull_user(&riov, buf, 5);
if (err != 1)
errx(1, "vringh_iov_pull_user: %i", err);
assert(buf[0] == 'a');
assert(riov.i == 1);
assert(vringh_iov_pull_user(&riov, buf, 5) == 0);
memcpy(buf, "bcdef", 5);
err = vringh_iov_push_user(&wiov, buf, 5);
if (err != 2)
errx(1, "vringh_iov_push_user: %i", err);
assert(memcmp(__user_addr_max - 3, "bc", 2) == 0);
assert(wiov.i == wiov.used);
assert(vringh_iov_push_user(&wiov, buf, 5) == 0);
/* Host is done. */
err = vringh_complete_user(&vrh, head, err);
if (err != 0)
errx(1, "vringh_complete_user: %i", err);
/* Guest should see used token now. */
__kfree_ignore_start = __user_addr_min + vring_size(RINGSIZE, ALIGN);
__kfree_ignore_end = __kfree_ignore_start + 1;
ret = virtqueue_get_buf(vq, &i);
if (ret != &err)
errx(1, "virtqueue_get_buf: %p", ret);
assert(i == 2);
/* Guest puts in a huge descriptor. */
sg_init_table(guest_sg, RINGSIZE);
for (i = 0; i < RINGSIZE; i++) {
sg_set_buf(&guest_sg[i],
__user_addr_max - USER_MEM/4, USER_MEM/4);
}
/* Fill contents with recognisable garbage. */
for (i = 0; i < USER_MEM/4; i++)
((char *)__user_addr_max - USER_MEM/4)[i] = i;
/* This will allocate an indirect, so force it to allocate user addr */
__kmalloc_fake = __user_addr_min + vring_size(RINGSIZE, ALIGN);
err = virtqueue_add_outbuf(vq, guest_sg, RINGSIZE, &err, GFP_KERNEL);
if (err)
errx(1, "virtqueue_add_outbuf (large): %i", err);
__kmalloc_fake = NULL;
/* Host picks it up (allocates new iov). */
vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
if (err != 1)
errx(1, "vringh_getdesc_user: %i", err);
assert(riov.max_num & VRINGH_IOV_ALLOCATED);
assert(riov.iov != host_riov);
if (getrange != getrange_slow)
assert(riov.used == RINGSIZE);
else
assert(riov.used == RINGSIZE * USER_MEM/4);
assert(!(wiov.max_num & VRINGH_IOV_ALLOCATED));
assert(wiov.used == 0);
/* Pull data back out (in odd chunks), should be as expected. */
for (i = 0; i < RINGSIZE * USER_MEM/4; i += 3) {
err = vringh_iov_pull_user(&riov, buf, 3);
if (err != 3 && i + err != RINGSIZE * USER_MEM/4)
errx(1, "vringh_iov_pull_user large: %i", err);
assert(buf[0] == (char)i);
assert(err < 2 || buf[1] == (char)(i + 1));
assert(err < 3 || buf[2] == (char)(i + 2));
}
assert(riov.i == riov.used);
vringh_iov_cleanup(&riov);
vringh_iov_cleanup(&wiov);
/* Complete using multi interface, just because we can. */
used[0].id = head;
used[0].len = 0;
err = vringh_complete_multi_user(&vrh, used, 1);
if (err)
errx(1, "vringh_complete_multi_user(1): %i", err);
/* Free up those descriptors. */
ret = virtqueue_get_buf(vq, &i);
if (ret != &err)
errx(1, "virtqueue_get_buf: %p", ret);
/* Add lots of descriptors. */
sg_init_table(guest_sg, 1);
sg_set_buf(&guest_sg[0], __user_addr_max - 1, 1);
for (i = 0; i < RINGSIZE; i++) {
err = virtqueue_add_outbuf(vq, guest_sg, 1, &err, GFP_KERNEL);
if (err)
errx(1, "virtqueue_add_outbuf (multiple): %i", err);
}
/* Now get many, and consume them all at once. */
vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
for (i = 0; i < RINGSIZE; i++) {
err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
if (err != 1)
errx(1, "vringh_getdesc_user: %i", err);
used[i].id = head;
used[i].len = 0;
}
/* Make sure it wraps around ring, to test! */
assert(vrh.vring.used->idx % RINGSIZE != 0);
err = vringh_complete_multi_user(&vrh, used, RINGSIZE);
if (err)
errx(1, "vringh_complete_multi_user: %i", err);
/* Free those buffers. */
for (i = 0; i < RINGSIZE; i++) {
unsigned len;
assert(virtqueue_get_buf(vq, &len) != NULL);
}
/* Test weird (but legal!) indirect. */
if (__virtio_test_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
char *data = __user_addr_max - USER_MEM/4;
struct vring_desc *d = __user_addr_max - USER_MEM/2;
struct vring vring;
/* Force creation of direct, which we modify. */
__virtio_clear_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC);
vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &vdev, true,
false, __user_addr_min,
never_notify_host,
never_callback_guest,
"guest vq");
sg_init_table(guest_sg, 4);
sg_set_buf(&guest_sg[0], d, sizeof(*d)*2);
sg_set_buf(&guest_sg[1], d + 2, sizeof(*d)*1);
sg_set_buf(&guest_sg[2], data + 6, 4);
sg_set_buf(&guest_sg[3], d + 3, sizeof(*d)*3);
err = virtqueue_add_outbuf(vq, guest_sg, 4, &err, GFP_KERNEL);
if (err)
errx(1, "virtqueue_add_outbuf (indirect): %i", err);
vring_init(&vring, RINGSIZE, __user_addr_min, ALIGN);
/* They're used in order, but double-check... */
assert(vring.desc[0].addr == (unsigned long)d);
assert(vring.desc[1].addr == (unsigned long)(d+2));
assert(vring.desc[2].addr == (unsigned long)data + 6);
assert(vring.desc[3].addr == (unsigned long)(d+3));
vring.desc[0].flags |= VRING_DESC_F_INDIRECT;
vring.desc[1].flags |= VRING_DESC_F_INDIRECT;
vring.desc[3].flags |= VRING_DESC_F_INDIRECT;
/* First indirect */
d[0].addr = (unsigned long)data;
d[0].len = 1;
d[0].flags = VRING_DESC_F_NEXT;
d[0].next = 1;
d[1].addr = (unsigned long)data + 1;
d[1].len = 2;
d[1].flags = 0;
/* Second indirect */
d[2].addr = (unsigned long)data + 3;
d[2].len = 3;
d[2].flags = 0;
/* Third indirect */
d[3].addr = (unsigned long)data + 10;
d[3].len = 5;
d[3].flags = VRING_DESC_F_NEXT;
d[3].next = 1;
d[4].addr = (unsigned long)data + 15;
d[4].len = 6;
d[4].flags = VRING_DESC_F_NEXT;
d[4].next = 2;
d[5].addr = (unsigned long)data + 21;
d[5].len = 7;
d[5].flags = 0;
/* Host picks it up (allocates new iov). */
vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
if (err != 1)
errx(1, "vringh_getdesc_user: %i", err);
if (head != 0)
errx(1, "vringh_getdesc_user: head %i not 0", head);
assert(riov.max_num & VRINGH_IOV_ALLOCATED);
if (getrange != getrange_slow)
assert(riov.used == 7);
else
assert(riov.used == 28);
err = vringh_iov_pull_user(&riov, buf, 29);
assert(err == 28);
/* Data should be linear. */
for (i = 0; i < err; i++)
assert(buf[i] == i);
vringh_iov_cleanup(&riov);
}
/* Don't leak memory... */
vring_del_virtqueue(vq);
free(__user_addr_min);
return 0;
}