Re: [PATCH net-next v3 10/12] test/vsock: MSG_ZEROCOPY flag tests
From: Stefano Garzarella
Date: Mon Oct 09 2023 - 11:18:19 EST
On Sat, Oct 07, 2023 at 08:21:37PM +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.
Patch also works as preparation for the next patches for tools in this
patchset: vsock_perf and vsock_uring_test:
1) Adds several new functions to util.c - they will be also used by
vsock_uring_test.
2) Adds two new functions for MSG_ZEROCOPY handling to a new header
file - such header will be shared between vsock_test, vsock_perf and
vsock_uring_test, thus avoiding code copy-pasting.
Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
---
Changelog:
v1 -> v2:
* Move 'SOL_VSOCK' and 'VSOCK_RECVERR' from 'util.c' to 'util.h'.
v2 -> v3:
* Patch was reworked. Now it is also preparation patch (see commit
message). Shared stuff for 'vsock_perf' and tests is placed to a
new header file, while shared code between current test tool and
future uring test is placed to the 'util.c'. I think, that making
this patch as preparation allows to reduce number of changes in the
next patches in this patchset.
* Make 'struct vsock_test_data' private by placing it to the .c file.
Also add comments to this struct to clarify sense of its fields.
tools/testing/vsock/Makefile | 2 +-
tools/testing/vsock/msg_zerocopy_common.h | 92 ++++++
tools/testing/vsock/util.c | 110 +++++++
tools/testing/vsock/util.h | 5 +
tools/testing/vsock/vsock_test.c | 16 +
tools/testing/vsock/vsock_test_zerocopy.c | 367 ++++++++++++++++++++++
tools/testing/vsock/vsock_test_zerocopy.h | 15 +
7 files changed, 606 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/vsock/msg_zerocopy_common.h
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/msg_zerocopy_common.h b/tools/testing/vsock/msg_zerocopy_common.h
new file mode 100644
index 000000000000..ce89f1281584
--- /dev/null
+++ b/tools/testing/vsock/msg_zerocopy_common.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef MSG_ZEROCOPY_COMMON_H
+#define MSG_ZEROCOPY_COMMON_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <linux/errqueue.h>
+
+#ifndef SOL_VSOCK
+#define SOL_VSOCK 287
+#endif
+
+#ifndef VSOCK_RECVERR
+#define VSOCK_RECVERR 1
+#endif
+
+static 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 vsock_recv_completion(int fd, const bool *zerocopied) __maybe_unused;
To avoid this, maybe we can implement those functions in .c file and
link the object.
WDYT?
Ah, here (cc (GCC) 13.2.1 20230728 (Red Hat 13.2.1-1)) the build is
failing:
In file included from vsock_perf.c:23:
msg_zerocopy_common.h: In function ‘vsock_recv_completion’:
msg_zerocopy_common.h:29:67: error: expected declaration specifiers before ‘__maybe_unused’
29 | static void vsock_recv_completion(int fd, const bool *zerocopied) __maybe_unused;
| ^~~~~~~~~~~~~~
msg_zerocopy_common.h:31:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
31 | {
| ^
+static void vsock_recv_completion(int fd, const bool *zerocopied)
+{
+ struct sock_extended_err *serr;
+ struct msghdr msg = { 0 };
+ char cmsg_data[128];
+ struct cmsghdr *cm;
+ ssize_t res;
+
+ 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);
+ exit(EXIT_FAILURE);
+ }
+
+ if (serr->ee_errno) {
+ fprintf(stderr, "serr: wrong error code: %u\n", serr->ee_errno);
+ exit(EXIT_FAILURE);
+ }
+
+ /* This flag is used for tests, to check that transmission was
+ * performed as expected: zerocopy or fallback to copy. If NULL
+ * - don't care.
+ */
+ if (!zerocopied)
+ return;
+
+ 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);
+ }
+}
+
+#endif /* MSG_ZEROCOPY_COMMON_H */
diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c
index 6779d5008b27..b1770edd8cc1 100644
--- a/tools/testing/vsock/util.c
+++ b/tools/testing/vsock/util.c
@@ -11,10 +11,12 @@
#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 "timeout.h"
#include "control.h"
@@ -444,3 +446,111 @@ unsigned long hash_djb2(const void *data, size_t len)
return hash;
}
+
+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;
+}
+
+unsigned long iovec_hash_djb2(const 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 iovec *test_iovec, int
iovnum)
From the name this function seems related to vsock_test_data, so I'd
suggest to move this and free_iovec_test_data() in vsock_test_zerocopy.c
+{
+ struct iovec *iovec;
+ int i;
+
+ iovec = malloc(sizeof(*iovec) * iovnum);
+ if (!iovec) {
+ perror("malloc");
+ exit(EXIT_FAILURE);
+ }
+
+ for (i = 0; i < iovnum; i++) {
+ iovec[i].iov_len = test_iovec[i].iov_len;
+
+ iovec[i].iov_base = mmap(NULL, iovec[i].iov_len,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE,
+ -1, 0);
+ if (iovec[i].iov_base == MAP_FAILED) {
+ perror("mmap");
+ exit(EXIT_FAILURE);
+ }
+
+ if (test_iovec[i].iov_base != MAP_FAILED)
+ iovec[i].iov_base += (uintptr_t)test_iovec[i].iov_base;
+ }
+
+ /* Unmap "invalid" elements. */
+ for (i = 0; i < iovnum; i++) {
+ if (test_iovec[i].iov_base == MAP_FAILED) {
+ if (munmap(iovec[i].iov_base, iovec[i].iov_len)) {
+ perror("munmap");
+ exit(EXIT_FAILURE);
+ }
+ }
+ }
+
+ for (i = 0; i < iovnum; i++) {
+ int j;
+
+ if (test_iovec[i].iov_base == MAP_FAILED)
+ continue;
+
+ for (j = 0; j < iovec[i].iov_len; j++)
+ ((uint8_t *)iovec[i].iov_base)[j] = rand() & 0xff;
+ }
+
+ return iovec;
+}
+
+void free_iovec_test_data(const struct iovec *test_iovec,
+ struct iovec *iovec, int iovnum)
+{
+ int i;
+
+ for (i = 0; i < iovnum; i++) {
+ if (test_iovec[i].iov_base != MAP_FAILED) {
+ if (test_iovec[i].iov_base)
+ iovec[i].iov_base -= (uintptr_t)test_iovec[i].iov_base;
+
+ if (munmap(iovec[i].iov_base, iovec[i].iov_len)) {
+ perror("munmap");
+ exit(EXIT_FAILURE);
+ }
+ }
+ }
+
+ free(iovec);
+}
diff --git a/tools/testing/vsock/util.h b/tools/testing/vsock/util.h
index e5407677ce05..4cacb8d804c1 100644
--- a/tools/testing/vsock/util.h
+++ b/tools/testing/vsock/util.h
@@ -53,4 +53,9 @@ 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);
+size_t iovec_bytes(const struct iovec *iov, size_t iovnum);
+unsigned long iovec_hash_djb2(const struct iovec *iov, size_t iovnum);
+struct iovec *iovec_from_test_data(const struct iovec *test_iovec, int iovnum);
+void free_iovec_test_data(const struct iovec *test_iovec,
+ struct iovec *iovec, int iovnum);
#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..af14efdf334b
--- /dev/null
+++ b/tools/testing/vsock/vsock_test_zerocopy.c
@@ -0,0 +1,367 @@
+// 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"
+#include "msg_zerocopy_common.h"
+
+#define PAGE_SIZE 4096
In some tests I saw `sysconf(_SC_PAGESIZE)` is used,
e.g. in selftests/ptrace/peeksiginfo.c:
#ifndef PAGE_SIZE
#define PAGE_SIZE sysconf(_SC_PAGESIZE)
#endif
WDYT?
+
+#define VSOCK_TEST_DATA_MAX_IOV 3
+
+struct vsock_test_data {
+ /* This test case if for SOCK_STREAM only. */
+ bool stream_only;
+ /* Data must be zerocopied. This field is checked against
+ * field 'ee_code' of the 'struct sock_extended_err', which
+ * contains bit to detect that zerocopy transmission was
+ * fallbacked to copy mode.
+ */
+ bool zerocopied;
+ /* Enable SO_ZEROCOPY option on the socket. Without enabled
+ * SO_ZEROCOPY, every MSG_ZEROCOPY transmission will behave
+ * like without MSG_ZEROCOPY flag.
+ */
+ bool so_zerocopy;
+ /* 'errno' after 'sendmsg()' call. */
+ int sendmsg_errno;
+ /* Number of valid elements in 'vecs'. */
+ int vecs_cnt;
+ /* Array how to allocate buffers for test.
+ * 'iov_base' == NULL -> valid buf: mmap('iov_len').
+ *
+ * 'iov_base' == MAP_FAILED -> invalid buf:
+ * mmap('iov_len'), then munmap('iov_len').
+ * 'iov_base' still contains result of
+ * mmap().
+ *
+ * 'iov_base' == number -> unaligned valid buf:
+ * mmap('iov_len') + number.
+ */
+ struct iovec vecs[VSOCK_TEST_DATA_MAX_IOV];
+};
+
+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 }
+ }
+ },
+};
+
+#define POLL_TIMEOUT_MS 100
+
+static void test_client(const struct test_opts *opts,
+ const struct vsock_test_data *test_data,
+ bool sock_seqpacket)
+{
+ struct pollfd fds = { 0 };
+ 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->vecs, test_data->vecs_cnt);
+
+ 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);
+ }
+ }
+
+ fds.fd = fd;
+ fds.events = 0;
+
+ if (poll(&fds, 1, POLL_TIMEOUT_MS) < 0) {
+ perror("poll");
+ exit(EXIT_FAILURE);
+ }
+
+ if (fds.revents & POLLERR) {
+ vsock_recv_completion(fd, &test_data->zerocopied);
+ } else if (test_data->so_zerocopy && !test_data->sendmsg_errno) {
+ /* If we don't have data in the error queue, but
+ * SO_ZEROCOPY was enabled and 'sendmsg()' was
+ * successful - this is an error.
+ */
+ fprintf(stderr, "POLLERR expected\n");
+ exit(EXIT_FAILURE);
+ }
+
+ 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->vecs, iovec, test_data->vecs_cnt);
+ 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