Re: [PATCH net-next v2 10/12] test/vsock: MSG_ZEROCOPY flag tests

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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?

+		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


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