Re: [PATCH net-next v2 10/12] test/vsock: MSG_ZEROCOPY flag tests
From: Arseniy Krasnov
Date: Wed Oct 04 2023 - 12:27:10 EST
On 04.10.2023 18:39, Stefano Garzarella wrote:
> On Sun, Oct 01, 2023 at 12:03:06AM +0300, Arseniy Krasnov wrote:
>> This adds three tests for MSG_ZEROCOPY feature:
>> 1) SOCK_STREAM tx with different buffers.
>> 2) SOCK_SEQPACKET tx with different buffers.
>> 3) SOCK_STREAM test to read empty error queue of the socket.
>>
>> Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
>> ---
>> Changelog:
>> v1 -> v2:
>> * Move 'SOL_VSOCK' and 'VSOCK_RECVERR' from 'util.c' to 'util.h'.
>>
>> tools/testing/vsock/Makefile | 2 +-
>> tools/testing/vsock/util.c | 214 +++++++++++++++
>> tools/testing/vsock/util.h | 27 ++
>> tools/testing/vsock/vsock_test.c | 16 ++
>> tools/testing/vsock/vsock_test_zerocopy.c | 314 ++++++++++++++++++++++
>> tools/testing/vsock/vsock_test_zerocopy.h | 15 ++
>> 6 files changed, 587 insertions(+), 1 deletion(-)
>> create mode 100644 tools/testing/vsock/vsock_test_zerocopy.c
>> create mode 100644 tools/testing/vsock/vsock_test_zerocopy.h
>>
>> diff --git a/tools/testing/vsock/Makefile b/tools/testing/vsock/Makefile
>> index 21a98ba565ab..1a26f60a596c 100644
>> --- a/tools/testing/vsock/Makefile
>> +++ b/tools/testing/vsock/Makefile
>> @@ -1,7 +1,7 @@
>> # SPDX-License-Identifier: GPL-2.0-only
>> all: test vsock_perf
>> test: vsock_test vsock_diag_test
>> -vsock_test: vsock_test.o timeout.o control.o util.o
>> +vsock_test: vsock_test.o vsock_test_zerocopy.o timeout.o control.o util.o
>> vsock_diag_test: vsock_diag_test.o timeout.o control.o util.o
>> vsock_perf: vsock_perf.o
>>
>> diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c
>> index 6779d5008b27..2a641ab38f08 100644
>> --- a/tools/testing/vsock/util.c
>> +++ b/tools/testing/vsock/util.c
>> @@ -11,10 +11,14 @@
>> #include <stdio.h>
>> #include <stdint.h>
>> #include <stdlib.h>
>> +#include <string.h>
>> #include <signal.h>
>> #include <unistd.h>
>> #include <assert.h>
>> #include <sys/epoll.h>
>> +#include <sys/mman.h>
>> +#include <linux/errqueue.h>
>> +#include <poll.h>
>>
>> #include "timeout.h"
>> #include "control.h"
>> @@ -444,3 +448,213 @@ unsigned long hash_djb2(const void *data, size_t len)
>>
>> return hash;
>> }
>> +
>> +void enable_so_zerocopy(int fd)
>> +{
>> + int val = 1;
>> +
>> + if (setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &val, sizeof(val))) {
>> + perror("setsockopt");
>> + exit(EXIT_FAILURE);
>> + }
>> +}
>> +
>> +static void *mmap_no_fail(size_t bytes)
>> +{
>> + void *res;
>> +
>> + res = mmap(NULL, bytes, PROT_READ | PROT_WRITE,
>> + MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0);
>> + if (res == MAP_FAILED) {
>> + perror("mmap");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + return res;
>> +}
>> +
>> +size_t iovec_bytes(const struct iovec *iov, size_t iovnum)
>> +{
>> + size_t bytes;
>> + int i;
>> +
>> + for (bytes = 0, i = 0; i < iovnum; i++)
>> + bytes += iov[i].iov_len;
>> +
>> + return bytes;
>> +}
>> +
>> +static void iovec_random_init(struct iovec *iov,
>> + const struct vsock_test_data *test_data)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < test_data->vecs_cnt; i++) {
>> + int j;
>> +
>> + if (test_data->vecs[i].iov_base == MAP_FAILED)
>> + continue;
>> +
>> + for (j = 0; j < iov[i].iov_len; j++)
>> + ((uint8_t *)iov[i].iov_base)[j] = rand() & 0xff;
>> + }
>> +}
>> +
>> +unsigned long iovec_hash_djb2(struct iovec *iov, size_t iovnum)
>> +{
>> + unsigned long hash;
>> + size_t iov_bytes;
>> + size_t offs;
>> + void *tmp;
>> + int i;
>> +
>> + iov_bytes = iovec_bytes(iov, iovnum);
>> +
>> + tmp = malloc(iov_bytes);
>> + if (!tmp) {
>> + perror("malloc");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + for (offs = 0, i = 0; i < iovnum; i++) {
>> + memcpy(tmp + offs, iov[i].iov_base, iov[i].iov_len);
>> + offs += iov[i].iov_len;
>> + }
>> +
>> + hash = hash_djb2(tmp, iov_bytes);
>> + free(tmp);
>> +
>> + return hash;
>> +}
>> +
>> +struct iovec *iovec_from_test_data(const struct vsock_test_data *test_data)
>> +{
>> + const struct iovec *test_iovec;
>> + struct iovec *iovec;
>> + int i;
>> +
>> + iovec = malloc(sizeof(*iovec) * test_data->vecs_cnt);
>> + if (!iovec) {
>> + perror("malloc");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + test_iovec = test_data->vecs;
>> +
>> + for (i = 0; i < test_data->vecs_cnt; i++) {
>> + iovec[i].iov_len = test_iovec[i].iov_len;
>> + iovec[i].iov_base = mmap_no_fail(test_iovec[i].iov_len);
>> +
>> + if (test_iovec[i].iov_base != MAP_FAILED &&
>> + test_iovec[i].iov_base)
>> + iovec[i].iov_base += (uintptr_t)test_iovec[i].iov_base;
>> + }
>> +
>> + /* Unmap "invalid" elements. */
>> + for (i = 0; i < test_data->vecs_cnt; i++) {
>> + if (test_iovec[i].iov_base == MAP_FAILED) {
>> + if (munmap(iovec[i].iov_base, iovec[i].iov_len)) {
>> + perror("munmap");
>> + exit(EXIT_FAILURE);
>> + }
>> + }
>> + }
>> +
>> + iovec_random_init(iovec, test_data);
>> +
>> + return iovec;
>> +}
>> +
>> +void free_iovec_test_data(const struct vsock_test_data *test_data,
>> + struct iovec *iovec)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < test_data->vecs_cnt; i++) {
>> + if (test_data->vecs[i].iov_base != MAP_FAILED) {
>> + if (test_data->vecs[i].iov_base)
>> + iovec[i].iov_base -= (uintptr_t)test_data->vecs[i].iov_base;
>> +
>> + if (munmap(iovec[i].iov_base, iovec[i].iov_len)) {
>> + perror("munmap");
>> + exit(EXIT_FAILURE);
>> + }
>> + }
>> + }
>> +
>> + free(iovec);
>> +}
>> +
>> +#define POLL_TIMEOUT_MS 100
>> +void vsock_recv_completion(int fd, bool zerocopied, bool completion)
>> +{
>> + struct sock_extended_err *serr;
>> + struct msghdr msg = { 0 };
>> + struct pollfd fds = { 0 };
>> + char cmsg_data[128];
>> + struct cmsghdr *cm;
>> + ssize_t res;
>> +
>> + fds.fd = fd;
>> + fds.events = 0;
>> +
>> + if (poll(&fds, 1, POLL_TIMEOUT_MS) < 0) {
>> + perror("poll");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (!(fds.revents & POLLERR)) {
>> + if (completion) {
>> + fprintf(stderr, "POLLERR expected\n");
>> + exit(EXIT_FAILURE);
>> + } else {
>> + return;
>> + }
>> + }
>> +
>> + msg.msg_control = cmsg_data;
>> + msg.msg_controllen = sizeof(cmsg_data);
>> +
>> + res = recvmsg(fd, &msg, MSG_ERRQUEUE);
>> + if (res) {
>> + fprintf(stderr, "failed to read error queue: %zi\n", res);
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + cm = CMSG_FIRSTHDR(&msg);
>> + if (!cm) {
>> + fprintf(stderr, "cmsg: no cmsg\n");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (cm->cmsg_level != SOL_VSOCK) {
>> + fprintf(stderr, "cmsg: unexpected 'cmsg_level'\n");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (cm->cmsg_type != VSOCK_RECVERR) {
>> + fprintf(stderr, "cmsg: unexpected 'cmsg_type'\n");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + serr = (void *)CMSG_DATA(cm);
>> + if (serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
>> + fprintf(stderr, "serr: wrong origin: %u\n", serr->ee_origin);
>
> What "serr" means?
serr == sock_extended_err, this function is based on the same logic from:
tools/testing/selftests/net/msg_zerocopy.c
>
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (serr->ee_errno) {
>> + fprintf(stderr, "serr: wrong error code: %u\n", serr->ee_errno);
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (zerocopied && (serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED)) {
>> + fprintf(stderr, "serr: was copy instead of zerocopy\n");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (!zerocopied && !(serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED)) {
>> + fprintf(stderr, "serr: was zerocopy instead of copy\n");
>> + exit(EXIT_FAILURE);
>> + }
>> +}
>
> Why we are putting this functions in util.c if they are only used by
> zerocopy tests?
>
>> diff --git a/tools/testing/vsock/util.h b/tools/testing/vsock/util.h
>> index e5407677ce05..407f415adef6 100644
>> --- a/tools/testing/vsock/util.h
>> +++ b/tools/testing/vsock/util.h
>> @@ -2,9 +2,18 @@
>> #ifndef UTIL_H
>> #define UTIL_H
>>
>> +#include <stdbool.h>
>> #include <sys/socket.h>
>> #include <linux/vm_sockets.h>
>>
>> +#ifndef SOL_VSOCK
>> +#define SOL_VSOCK 287
>> +#endif
>> +
>> +#ifndef VSOCK_RECVERR
>> +#define VSOCK_RECVERR 1
>> +#endif
>> +
>> /* Tests can either run as the client or the server */
>> enum test_mode {
>> TEST_MODE_UNSET,
>> @@ -18,6 +27,17 @@ struct test_opts {
>> unsigned int peer_cid;
>> };
>>
>
> Ditto.
>
>> +#define VSOCK_TEST_DATA_MAX_IOV 4
>> +
>> +struct vsock_test_data {
>> + bool stream_only; /* Only for SOCK_STREAM. */
>> + bool zerocopied; /* Data must be zerocopied. */
>> + bool so_zerocopy; /* Enable zerocopy mode. */
>
> What is the difference between `zerocopied` and `so_zerocopy`?
> We should explain better, or change the names, they are a bit confusing.
>
>> + int sendmsg_errno; /* 'errno' after 'sendmsg()'. */
>> + int vecs_cnt; /* Number of elements in 'vecs'. */
>> + struct iovec vecs[VSOCK_TEST_DATA_MAX_IOV];
>> +};
>> +
>> /* A test case definition. Test functions must print failures to stderr and
>> * terminate with exit(EXIT_FAILURE).
>> */
>> @@ -53,4 +73,11 @@ void list_tests(const struct test_case *test_cases);
>> void skip_test(struct test_case *test_cases, size_t test_cases_len,
>> const char *test_id_str);
>> unsigned long hash_djb2(const void *data, size_t len);
>> +void enable_so_zerocopy(int fd);
>> +size_t iovec_bytes(const struct iovec *iov, size_t iovnum);
>> +unsigned long iovec_hash_djb2(struct iovec *iov, size_t iovnum);
>> +struct iovec *iovec_from_test_data(const struct vsock_test_data *test_data);
>> +void free_iovec_test_data(const struct vsock_test_data *test_data,
>> + struct iovec *iovec);
>> +void vsock_recv_completion(int fd, bool zerocopied, bool completion);
>> #endif /* UTIL_H */
>> diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
>> index da4cb819a183..c1f7bc9abd22 100644
>> --- a/tools/testing/vsock/vsock_test.c
>> +++ b/tools/testing/vsock/vsock_test.c
>> @@ -21,6 +21,7 @@
>> #include <poll.h>
>> #include <signal.h>
>>
>> +#include "vsock_test_zerocopy.h"
>> #include "timeout.h"
>> #include "control.h"
>> #include "util.h"
>> @@ -1269,6 +1270,21 @@ static struct test_case test_cases[] = {
>> .run_client = test_stream_shutrd_client,
>> .run_server = test_stream_shutrd_server,
>> },
>> + {
>> + .name = "SOCK_STREAM MSG_ZEROCOPY",
>> + .run_client = test_stream_msgzcopy_client,
>> + .run_server = test_stream_msgzcopy_server,
>> + },
>> + {
>> + .name = "SOCK_SEQPACKET MSG_ZEROCOPY",
>> + .run_client = test_seqpacket_msgzcopy_client,
>> + .run_server = test_seqpacket_msgzcopy_server,
>> + },
>> + {
>> + .name = "SOCK_STREAM MSG_ZEROCOPY empty MSG_ERRQUEUE",
>> + .run_client = test_stream_msgzcopy_empty_errq_client,
>> + .run_server = test_stream_msgzcopy_empty_errq_server,
>> + },
>> {},
>> };
>>
>> diff --git a/tools/testing/vsock/vsock_test_zerocopy.c b/tools/testing/vsock/vsock_test_zerocopy.c
>> new file mode 100644
>> index 000000000000..655ef92ef25d
>> --- /dev/null
>> +++ b/tools/testing/vsock/vsock_test_zerocopy.c
>> @@ -0,0 +1,314 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/* MSG_ZEROCOPY feature tests for vsock
>> + *
>> + * Copyright (C) 2023 SberDevices.
>> + *
>> + * Author: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
>> + */
>> +
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <string.h>
>> +#include <sys/mman.h>
>> +#include <unistd.h>
>> +#include <poll.h>
>> +#include <linux/errqueue.h>
>> +#include <linux/kernel.h>
>> +#include <errno.h>
>> +
>> +#include "control.h"
>> +#include "vsock_test_zerocopy.h"
>> +
>> +#define PAGE_SIZE 4096
>
> I think we can move all the util.c/util.h changes here.
>
>> +
>> +static struct vsock_test_data test_data_array[] = {
>> + /* Last element has non-page aligned size. */
>> + {
>> + .zerocopied = true,
>> + .so_zerocopy = true,
>> + .sendmsg_errno = 0,
>> + .vecs_cnt = 3,
>> + {
>> + { NULL, PAGE_SIZE },
>> + { NULL, PAGE_SIZE },
>> + { NULL, 200 }
>> + }
>> + },
>> + /* All elements have page aligned base and size. */
>> + {
>> + .zerocopied = true,
>> + .so_zerocopy = true,
>> + .sendmsg_errno = 0,
>> + .vecs_cnt = 3,
>> + {
>> + { NULL, PAGE_SIZE },
>> + { NULL, PAGE_SIZE * 2 },
>> + { NULL, PAGE_SIZE * 3 }
>> + }
>> + },
>> + /* All elements have page aligned base and size. But
>> + * data length is bigger than 64Kb.
>> + */
>> + {
>> + .zerocopied = true,
>> + .so_zerocopy = true,
>> + .sendmsg_errno = 0,
>> + .vecs_cnt = 3,
>> + {
>> + { NULL, PAGE_SIZE * 16 },
>> + { NULL, PAGE_SIZE * 16 },
>> + { NULL, PAGE_SIZE * 16 }
>> + }
>> + },
>> + /* Middle element has both non-page aligned base and size. */
>> + {
>> + .zerocopied = true,
>> + .so_zerocopy = true,
>> + .sendmsg_errno = 0,
>> + .vecs_cnt = 3,
>> + {
>> + { NULL, PAGE_SIZE },
>> + { (void *)1, 100 },
>> + { NULL, PAGE_SIZE }
>> + }
>> + },
>> + /* Middle element is unmapped. */
>> + {
>> + .zerocopied = false,
>> + .so_zerocopy = true,
>> + .sendmsg_errno = ENOMEM,
>> + .vecs_cnt = 3,
>> + {
>> + { NULL, PAGE_SIZE },
>> + { MAP_FAILED, PAGE_SIZE },
>> + { NULL, PAGE_SIZE }
>> + }
>> + },
>> + /* Valid data, but SO_ZEROCOPY is off. This
>> + * will trigger fallback to copy.
>> + */
>> + {
>> + .zerocopied = false,
>> + .so_zerocopy = false,
>> + .sendmsg_errno = 0,
>> + .vecs_cnt = 1,
>> + {
>> + { NULL, PAGE_SIZE }
>> + }
>> + },
>> + /* Valid data, but message is bigger than peer's
>> + * buffer, so this will trigger fallback to copy.
>> + * This test is for SOCK_STREAM only, because
>> + * for SOCK_SEQPACKET, 'sendmsg()' returns EMSGSIZE.
>> + */
>> + {
>> + .stream_only = true,
>> + .zerocopied = false,
>> + .so_zerocopy = true,
>> + .sendmsg_errno = 0,
>> + .vecs_cnt = 1,
>> + {
>> + { NULL, 100 * PAGE_SIZE }
>> + }
>> + },
>> +};
>> +
>> +static void test_client(const struct test_opts *opts,
>> + const struct vsock_test_data *test_data,
>> + bool sock_seqpacket)
>> +{
>> + struct msghdr msg = { 0 };
>> + ssize_t sendmsg_res;
>> + struct iovec *iovec;
>> + int fd;
>> +
>> + if (sock_seqpacket)
>> + fd = vsock_seqpacket_connect(opts->peer_cid, 1234);
>> + else
>> + fd = vsock_stream_connect(opts->peer_cid, 1234);
>> +
>> + if (fd < 0) {
>> + perror("connect");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (test_data->so_zerocopy)
>> + enable_so_zerocopy(fd);
>> +
>> + iovec = iovec_from_test_data(test_data);
>> +
>> + msg.msg_iov = iovec;
>> + msg.msg_iovlen = test_data->vecs_cnt;
>> +
>> + errno = 0;
>> +
>> + sendmsg_res = sendmsg(fd, &msg, MSG_ZEROCOPY);
>> + if (errno != test_data->sendmsg_errno) {
>> + fprintf(stderr, "expected 'errno' == %i, got %i\n",
>> + test_data->sendmsg_errno, errno);
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + if (!errno) {
>> + if (sendmsg_res != iovec_bytes(iovec, test_data->vecs_cnt)) {
>> + fprintf(stderr, "expected 'sendmsg()' == %li, got %li\n",
>> + iovec_bytes(iovec, test_data->vecs_cnt),
>> + sendmsg_res);
>> + exit(EXIT_FAILURE);
>> + }
>> + }
>> +
>> + /* Receive completion only in case of successful 'sendmsg()'. */
>> + vsock_recv_completion(fd, test_data->zerocopied,
>> + test_data->so_zerocopy && !test_data->sendmsg_errno);
>> +
>> + if (!test_data->sendmsg_errno)
>> + control_writeulong(iovec_hash_djb2(iovec, test_data->vecs_cnt));
>> + else
>> + control_writeulong(0);
>> +
>> + control_writeln("DONE");
>> + free_iovec_test_data(test_data, iovec);
>> + close(fd);
>> +}
>> +
>> +void test_stream_msgzcopy_client(const struct test_opts *opts)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(test_data_array); i++)
>> + test_client(opts, &test_data_array[i], false);
>> +}
>> +
>> +void test_seqpacket_msgzcopy_client(const struct test_opts *opts)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(test_data_array); i++) {
>> + if (test_data_array[i].stream_only)
>> + continue;
>> +
>> + test_client(opts, &test_data_array[i], true);
>> + }
>> +}
>> +
>> +static void test_server(const struct test_opts *opts,
>> + const struct vsock_test_data *test_data,
>> + bool sock_seqpacket)
>> +{
>> + unsigned long remote_hash;
>> + unsigned long local_hash;
>> + ssize_t total_bytes_rec;
>> + unsigned char *data;
>> + size_t data_len;
>> + int fd;
>> +
>> + if (sock_seqpacket)
>> + fd = vsock_seqpacket_accept(VMADDR_CID_ANY, 1234, NULL);
>> + else
>> + fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
>> +
>> + if (fd < 0) {
>> + perror("accept");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + data_len = iovec_bytes(test_data->vecs, test_data->vecs_cnt);
>> +
>> + data = malloc(data_len);
>> + if (!data) {
>> + perror("malloc");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + total_bytes_rec = 0;
>> +
>> + while (total_bytes_rec != data_len) {
>> + ssize_t bytes_rec;
>> +
>> + bytes_rec = read(fd, data + total_bytes_rec,
>> + data_len - total_bytes_rec);
>> + if (bytes_rec <= 0)
>> + break;
>> +
>> + total_bytes_rec += bytes_rec;
>> + }
>> +
>> + if (test_data->sendmsg_errno == 0)
>> + local_hash = hash_djb2(data, data_len);
>> + else
>> + local_hash = 0;
>> +
>> + free(data);
>> +
>> + /* Waiting for some result. */
>> + remote_hash = control_readulong();
>> + if (remote_hash != local_hash) {
>> + fprintf(stderr, "hash mismatch\n");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + control_expectln("DONE");
>> + close(fd);
>> +}
>> +
>> +void test_stream_msgzcopy_server(const struct test_opts *opts)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(test_data_array); i++)
>> + test_server(opts, &test_data_array[i], false);
>> +}
>> +
>> +void test_seqpacket_msgzcopy_server(const struct test_opts *opts)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(test_data_array); i++) {
>> + if (test_data_array[i].stream_only)
>> + continue;
>> +
>> + test_server(opts, &test_data_array[i], true);
>> + }
>> +}
>> +
>> +void test_stream_msgzcopy_empty_errq_client(const struct test_opts *opts)
>> +{
>> + struct msghdr msg = { 0 };
>> + char cmsg_data[128];
>> + ssize_t res;
>> + int fd;
>> +
>> + fd = vsock_stream_connect(opts->peer_cid, 1234);
>> + if (fd < 0) {
>> + perror("connect");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + msg.msg_control = cmsg_data;
>> + msg.msg_controllen = sizeof(cmsg_data);
>> +
>> + res = recvmsg(fd, &msg, MSG_ERRQUEUE);
>> + if (res != -1) {
>> + fprintf(stderr, "expected 'recvmsg(2)' failure, got %zi\n",
>> + res);
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + control_writeln("DONE");
>> + close(fd);
>> +}
>> +
>> +void test_stream_msgzcopy_empty_errq_server(const struct test_opts *opts)
>> +{
>> + int fd;
>> +
>> + fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
>> + if (fd < 0) {
>> + perror("accept");
>> + exit(EXIT_FAILURE);
>> + }
>> +
>> + control_expectln("DONE");
>> + close(fd);
>> +}
>> diff --git a/tools/testing/vsock/vsock_test_zerocopy.h b/tools/testing/vsock/vsock_test_zerocopy.h
>> new file mode 100644
>> index 000000000000..3ef2579e024d
>> --- /dev/null
>> +++ b/tools/testing/vsock/vsock_test_zerocopy.h
>> @@ -0,0 +1,15 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +#ifndef VSOCK_TEST_ZEROCOPY_H
>> +#define VSOCK_TEST_ZEROCOPY_H
>> +#include "util.h"
>> +
>> +void test_stream_msgzcopy_client(const struct test_opts *opts);
>> +void test_stream_msgzcopy_server(const struct test_opts *opts);
>> +
>> +void test_seqpacket_msgzcopy_client(const struct test_opts *opts);
>> +void test_seqpacket_msgzcopy_server(const struct test_opts *opts);
>> +
>> +void test_stream_msgzcopy_empty_errq_client(const struct test_opts *opts);
>> +void test_stream_msgzcopy_empty_errq_server(const struct test_opts *opts);
>> +
>> +#endif /* VSOCK_TEST_ZEROCOPY_H */
>> --
>> 2.25.1
>>
>