[LTP] [PATCH V7] syscall: Add io_uring related tests

Vikas Kumar
2020-06-29T05:59:56Z

Added asynchronous I/O API tests for io_uring_setup(), io_uring_register()
and io_uring_enter(). These tests intend to validate io_uring operations.

1. io_uring_setup() creates submission queue and completion queue to
perform subsequent operations on the io_uring instance.
2. io_uring_register() registers user buffers in kernel for long term
usese.
3. io_uring_enter() initiates I/O operations using the shared SQ and CQ
queue.

Signed-off-by: Vikas Kumar <vikas.kumar2@arm.com>
---
include/lapi/io_uring.h | 12 ++
testcases/kernel/syscalls/io_uring/Makefile | 7 +
.../kernel/syscalls/io_uring/io_uring01.c | 203 ++++++++++++++++++
3 files changed, 222 insertions(+)
create mode 100644 testcases/kernel/syscalls/io_uring/Makefile
create mode 100644 testcases/kernel/syscalls/io_uring/io_uring01.c

diff --git a/include/lapi/io_uring.h b/include/lapi/io_uring.h
index 5fde58e22..8e47501a5 100644
--- a/include/lapi/io_uring.h
+++ b/include/lapi/io_uring.h
@@ -280,4 +280,16 @@ int io_uring_enter(int fd, unsigned int to_submit, unsigned int min_complete,
}
#endif /* HAVE_IO_URING_ENTER */

+void io_uring_setup_supported_by_kernel(void)
+{
+ if ((tst_kvercmp(5, 1, 0)) < 0) {
+ TEST(syscall(__NR_io_uring_setup, NULL, 0));
+ if (TST_RET != -1)
+ SAFE_CLOSE(TST_RET);
+ else if (TST_ERR == ENOSYS)
+ tst_brk(TCONF,
+ "Test not supported on kernel version < v5.1");
+ }
+}
+
#endif /* IO_URING_H__ */
diff --git a/testcases/kernel/syscalls/io_uring/Makefile b/testcases/kernel/syscalls/io_uring/Makefile
new file mode 100644
index 000000000..94a19de2f
--- /dev/null
+++ b/testcases/kernel/syscalls/io_uring/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2020 ARM Ltd. All rights reserved.
+
+top_srcdir ?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/syscalls/io_uring/io_uring01.c b/testcases/kernel/syscalls/io_uring/io_uring01.c
new file mode 100644
index 000000000..738a2cb46
--- /dev/null
+++ b/testcases/kernel/syscalls/io_uring/io_uring01.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 ARM Ltd. All rights reserved.
+ * Author: Vikas Kumar <vikas.kumar2@arm.com>
+ *
+ * Tests for asynchronous I/O raw API i.e io_uring_setup(), io_uring_register()
+ * and io_uring_enter(). This tests validate basic API operation by creating a
+ * submission queue and a completion queue using io_uring_setup(). User buffer
+ * registered in the kernel for long term operation using io_uring_register().
+ * This tests initiates I/O operations with the help of io_uring_enter().
+ */
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include "config.h"
+#include "tst_test.h"
+#include "lapi/io_uring.h"
+
+#define QUEUE_DEPTH 1
+#define BLOCK_SZ 1024
+
+static struct tcase {
+ unsigned int setup_flags;
+ unsigned int register_opcode;
+ unsigned int enter_flags;
+} tcases[] = {
+ {IORING_SETUP_IOPOLL, IORING_REGISTER_BUFFERS, IORING_OP_READ_FIXED},
+};
+
+struct io_sq_ring {
+ unsigned int *head;
+ unsigned int *tail;
+ unsigned int *ring_mask;
+ unsigned int *ring_entries;
+ unsigned int *flags;
+ unsigned int *array;
+};
+
+struct io_cq_ring {
+ unsigned int *head;
+ unsigned int *tail;
+ unsigned int *ring_mask;
+ unsigned int *ring_entries;
+ struct io_uring_cqe *cqes;
+};
+
+struct submitter {
+ int ring_fd;
+ struct io_sq_ring sq_ring;
+ struct io_uring_sqe *sqes;
+ struct io_cq_ring cq_ring;
+};
+
+struct buff_info {
+ unsigned int buff_sz;
+ struct iovec iovecs[];
+};
+
+static struct submitter sub_ring;
+static struct submitter *s;
+static struct buff_info *bi;
+static sigset_t sig;
+
+static int setup_io_uring_test(struct submitter *s, struct tcase *tc)
+{
+ struct io_sq_ring *sring = &s->sq_ring;
+ struct io_cq_ring *cring = &s->cq_ring;
+ struct io_uring_params p;
+ void *ptr;
+
+ memset(&p, 0, sizeof(p));
+ p.flags |= tc->setup_flags;
+ s->ring_fd = io_uring_setup(QUEUE_DEPTH, &p);
+ if (s->ring_fd != -1) {
+ tst_res(TPASS, "io_uring_setup() passed");
+ } else {
+ tst_res(TFAIL | TTERRNO, "io_uring_setup() failed");
+ return 1;
+ }
+
+ /* Submission queue ring buffer mapping */
+ ptr = SAFE_MMAP(0, p.sq_off.array +
+ p.sq_entries * sizeof(unsigned int),
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE,
+ s->ring_fd, IORING_OFF_SQ_RING);
+
+ /* Save global submission queue struct info */
+ sring->head = ptr + p.sq_off.head;
+ sring->tail = ptr + p.sq_off.tail;
+ sring->ring_mask = ptr + p.sq_off.ring_mask;
+ sring->ring_entries = ptr + p.sq_off.ring_entries;
+ sring->flags = ptr + p.sq_off.flags;
+ sring->array = ptr + p.sq_off.array;
+
+ /* Submission queue entries ring buffer mapping */
+ s->sqes = SAFE_MMAP(0, p.sq_entries *
+ sizeof(struct io_uring_sqe),
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE,
+ s->ring_fd, IORING_OFF_SQES);
+
+ /* Completion queue ring buffer mapping */
+ ptr = SAFE_MMAP(0,
+ p.cq_off.cqes + p.cq_entries *
+ sizeof(struct io_uring_cqe),
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE,
+ s->ring_fd, IORING_OFF_CQ_RING);
+
+ /* Save global completion queue struct info */
+ cring->head = ptr + p.cq_off.head;
+ cring->tail = ptr + p.cq_off.tail;
+ cring->ring_mask = ptr + p.cq_off.ring_mask;
+ cring->ring_entries = ptr + p.cq_off.ring_entries;
+ cring->cqes = ptr + p.cq_off.cqes;
+
+ return 0;
+}
+
+static int submit_to_uring_sq(struct submitter *s, struct tcase *tc)
+{
+ unsigned int index = 0, tail = 0, next_tail = 0;
+ struct io_sq_ring *sring = &s->sq_ring;
+ struct io_uring_sqe *sqe;
+ void *iov_base;
+ size_t iov_len;
+ int ret;
+
+ bi = SAFE_MALLOC(sizeof(*bi));
+ iov_len = BLOCK_SZ;
+ iov_base = SAFE_MALLOC(iov_len);
+ memset(iov_base, 0, iov_len);
+ bi->iovecs[index].iov_base = (void *)iov_base;
+ bi->iovecs[index].iov_len = (size_t)iov_len;
+
+ ret = io_uring_register(s->ring_fd, tc->register_opcode,
+ bi->iovecs, QUEUE_DEPTH);
+ if (ret == 0) {
+ tst_res(TPASS, "io_uring_register() passed");
+ } else {
+ tst_res(TFAIL | TTERRNO, "io_uring_register() failed");
+ return 1;
+ }
+
+ /* Submission queue entry addition to SQE ring buffer tail */
+ tail = *sring->tail;
+ next_tail = tail;
+ next_tail++;
+ index = tail & *s->sq_ring.ring_mask;
+ sqe = &s->sqes[index];
+ sqe->flags = 0;
+ sqe->opcode = tc->enter_flags;
+ sqe->addr = (unsigned long)bi->iovecs;
+ sqe->user_data = (unsigned long long)bi;
+ sring->array[index] = index;
+ tail = next_tail;
+
+ /* Kernel to notice the tail update */
+ if (*sring->tail != tail)
+ *sring->tail = tail;
+
+ ret = io_uring_enter(s->ring_fd, 1, 1, IORING_ENTER_GETEVENTS, &sig);
+ if (ret >= 0) {
+ tst_res(TPASS, "io_uring_enter() passed");
+ } else {
+ tst_res(TFAIL | TTERRNO, "io_uring_enter() failed");
+ return 1;
+ }
+
+ return 0;
+}
+
+static void cleanup_io_uring_test(void)
+{
+ io_uring_register(s->ring_fd, IORING_UNREGISTER_BUFFERS,
+ NULL, QUEUE_DEPTH);
+ SAFE_MUNMAP(s->sqes, sizeof(struct io_uring_sqe));
+}
+
+static void run(unsigned int n)
+{
+ struct tcase *tc = &tcases[n];
+
+ s = &sub_ring;
+ memset(s, 0, sizeof(*s));
+ if (setup_io_uring_test(s, tc))
+ return;
+
+ if (submit_to_uring_sq(s, tc))
+ return;
+
+ cleanup_io_uring_test();
+ tst_res(TPASS, "functionality of io_uring API is correct");
+}
+
+static struct tst_test test = {
+ .setup = io_uring_setup_supported_by_kernel,
+ .test = run,
+ .tcnt = ARRAY_SIZE(tcases),
+};
+
--
2.17.1