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Diffstat (limited to '')
| -rw-r--r-- | tools/virtio/vringh_test.c | 751 |
1 files changed, 751 insertions, 0 deletions
diff --git a/tools/virtio/vringh_test.c b/tools/virtio/vringh_test.c new file mode 100644 index 000000000..293653463 --- /dev/null +++ b/tools/virtio/vringh_test.c @@ -0,0 +1,751 @@ +// 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; + 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; + + 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; +} |