[PATCH v2 6/8] selftests: ublk: add support for --io_desc_size

[Caleb Sander Mateos <csander@purestorage.com>]

Add an optional --io_desc_size argument to the kublk add/recover
commands to enable UBLK_F_IO_DESC on the ublk device. The mmap()
arguments and ublk_get_iod() computation are adjusted accordingly.

Display the configured io_desc_size in the kublk list output for ublk
devices with UBLK_F_IO_DESC.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/kublk.c | 29 +++++++++++++++++++---------
 tools/testing/selftests/ublk/kublk.h |  6 ++++--
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c
index 5c4a1f18d0a3..0e3e2d74cc4d 100644
--- a/tools/testing/selftests/ublk/kublk.c
+++ b/tools/testing/selftests/ublk/kublk.c
@@ -350,10 +350,12 @@ static void ublk_ctrl_dump(struct ublk_dev *dev)
 			info->dev_id, info->nr_hw_queues, info->queue_depth,
 			1 << p.basic.logical_bs_shift, p.basic.dev_sectors);
 	ublk_log("\tmax rq size %d daemon pid %d flags 0x%llx state %s\n",
 			info->max_io_buf_bytes, info->ublksrv_pid, info->flags,
 			ublk_dev_state_desc(dev));
+	if (info->flags & UBLK_F_IO_DESC_SIZE)
+		ublk_log("\tio_desc_size %u\n", info->io_desc_size);
 
 	if (affinity) {
 		char buf[512];
 		int i;
 
@@ -398,26 +400,26 @@ static struct ublk_dev *ublk_ctrl_init(void)
 	dev->nr_fds = 1;
 
 	return dev;
 }
 
-static int __ublk_queue_cmd_buf_sz(unsigned depth)
+static size_t __ublk_queue_cmd_buf_sz(const struct ublk_queue *q, __u16 depth)
 {
-	int size =  depth * sizeof(struct ublksrv_io_desc);
-	unsigned int page_sz = getpagesize();
+	size_t size = depth * (size_t)q->io_desc_size;
+	size_t page_sz = getpagesize();
 
 	return round_up(size, page_sz);
 }
 
-static int ublk_queue_max_cmd_buf_sz(void)
+static size_t ublk_queue_max_cmd_buf_sz(const struct ublk_queue *q)
 {
-	return __ublk_queue_cmd_buf_sz(UBLK_MAX_QUEUE_DEPTH);
+	return __ublk_queue_cmd_buf_sz(q, UBLK_MAX_QUEUE_DEPTH);
 }
 
-static int ublk_queue_cmd_buf_sz(struct ublk_queue *q)
+static size_t ublk_queue_cmd_buf_sz(const struct ublk_queue *q)
 {
-	return __ublk_queue_cmd_buf_sz(q->q_depth);
+	return __ublk_queue_cmd_buf_sz(q, q->q_depth);
 }
 
 static void ublk_queue_deinit(struct ublk_queue *q)
 {
 	int i;
@@ -451,26 +453,27 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned long long extra_flags,
 			   __u8 metadata_size)
 {
 	struct ublk_dev *dev = q->dev;
 	int depth = dev->dev_info.queue_depth;
 	int i;
-	int cmd_buf_size, io_buf_size, integrity_size;
+	size_t cmd_buf_size, io_buf_size, integrity_size;
 	unsigned long off;
 
 	pthread_spin_init(&q->lock, PTHREAD_PROCESS_PRIVATE);
 	q->tgt_ops = dev->tgt.ops;
 	q->flags = 0;
 	q->q_depth = depth;
 	q->flags = dev->dev_info.flags;
 	q->flags |= extra_flags;
 	q->metadata_size = metadata_size;
+	q->io_desc_size = dev->dev_info.io_desc_size;
 
 	/* Cache fd in queue for fast path access */
 	q->ublk_fd = dev->fds[0];
 
 	cmd_buf_size = ublk_queue_cmd_buf_sz(q);
-	off = UBLKSRV_CMD_BUF_OFFSET + q->q_id * ublk_queue_max_cmd_buf_sz();
+	off = UBLKSRV_CMD_BUF_OFFSET + q->q_id * ublk_queue_max_cmd_buf_sz(q);
 	q->io_cmd_buf = mmap(0, cmd_buf_size, PROT_READ,
 			MAP_SHARED | MAP_POPULATE, dev->fds[0], off);
 	if (q->io_cmd_buf == MAP_FAILED) {
 		ublk_err("ublk dev %d queue %d map io_cmd_buf failed %m\n",
 				q->dev->dev_info.dev_id, q->q_id);
@@ -1706,10 +1709,11 @@ static int __cmd_dev_add(const struct dev_ctx *ctx)
 
 	info = &dev->dev_info;
 	info->dev_id = ctx->dev_id;
 	info->nr_hw_queues = nr_queues;
 	info->queue_depth = depth;
+	info->io_desc_size = ctx->io_desc_size;
 	info->flags = ctx->flags;
 	if ((features & UBLK_F_QUIESCE) &&
 			(info->flags & UBLK_F_USER_RECOVERY))
 		info->flags |= UBLK_F_QUIESCE;
 	dev->nthreads = nthreads;
@@ -2067,10 +2071,11 @@ static void __cmd_create_help(char *exe, bool recovery)
 	printf("\t[-e 0|1 ] [-i 0|1] [--no_ublk_fixed_fd]\n");
 	printf("\t[--nthreads threads] [--per_io_tasks]\n");
 	printf("\t[--integrity_capable] [--integrity_reftag] [--metadata_size SIZE] "
 		 "[--pi_offset OFFSET] [--csum_type ip|t10dif|nvme] [--tag_size SIZE]\n");
 	printf("\t[--batch|-b] [--no_auto_part_scan]\n");
+	printf("\t[--io_desc_size SIZE]\n");
 	printf("\t[target options] [backfile1] [backfile2] ...\n");
 	printf("\tdefault: nr_queues=2(max 32), depth=128(max 1024), dev_id=-1(auto allocation)\n");
 	printf("\tdefault: nthreads=nr_queues");
 
 	for (i = 0; i < ARRAY_SIZE(tgt_ops_list); i++) {
@@ -2144,10 +2149,11 @@ int main(int argc, char *argv[])
 		{ "batch",              0,      NULL, 'b'},
 		{ "no_auto_part_scan",	0,	NULL,  0 },
 		{ "shmem_zc",		0,	NULL,  0  },
 		{ "htlb",		1,	NULL,  0  },
 		{ "rdonly_shmem_buf",	0,	NULL,  0  },
+		{ "io_desc_size",	1,	NULL,  0  },
 		{ 0, 0, 0, 0 }
 	};
 	const struct ublk_tgt_ops *ops = NULL;
 	int option_idx, opt;
 	const char *cmd = argv[1];
@@ -2156,10 +2162,11 @@ int main(int argc, char *argv[])
 		.queue_depth	=	128,
 		.nr_hw_queues	=	2,
 		.dev_id		=	-1,
 		.tgt_type	=	"unknown",
 		.csum_type	=	LBMD_PI_CSUM_NONE,
+		.io_desc_size	=	sizeof(struct ublksrv_io_desc),
 	};
 	int ret = -EINVAL, i;
 	int tgt_argc = 1;
 	char *tgt_argv[MAX_NR_TGT_ARG] = { NULL };
 	int value;
@@ -2265,10 +2272,14 @@ int main(int argc, char *argv[])
 				ctx.flags |= UBLK_F_SHMEM_ZC;
 			if (!strcmp(longopts[option_idx].name, "htlb"))
 				ctx.htlb_path = strdup(optarg);
 			if (!strcmp(longopts[option_idx].name, "rdonly_shmem_buf"))
 				ctx.rdonly_shmem_buf = 1;
+			if (!strcmp(longopts[option_idx].name, "io_desc_size")) {
+				ctx.flags |= UBLK_F_IO_DESC_SIZE;
+				ctx.io_desc_size = strtoul(optarg, NULL, 0);
+			}
 			break;
 		case '?':
 			/*
 			 * target requires every option must have argument
 			 */
diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h
index 742c41d77df1..15b56ff45bb6 100644
--- a/tools/testing/selftests/ublk/kublk.h
+++ b/tools/testing/selftests/ublk/kublk.h
@@ -85,10 +85,11 @@ struct dev_ctx {
 	__u32 integrity_flags;
 	__u8 metadata_size;
 	__u8 pi_offset;
 	__u8 csum_type;
 	__u8 tag_size;
+	__u16 io_desc_size;
 
 	int _evtfd;
 	int _shmid;
 
 	/* built from shmem, only for ublk_dump_dev() */
@@ -185,10 +186,11 @@ struct ublk_queue {
 #define UBLKS_Q_NO_UBLK_FIXED_FD	(1ULL << 62)
 #define UBLKS_Q_PREPARED	(1ULL << 61)
 	__u64 flags;
 	int ublk_fd;	/* cached ublk char device fd */
 	__u8 metadata_size;
+	__u16 io_desc_size;
 	struct ublk_io ios[UBLK_QUEUE_DEPTH];
 
 	/* used for prep io commands */
 	pthread_spinlock_t lock;
 };
@@ -459,13 +461,13 @@ static inline void ublk_mark_io_done(struct ublk_io *io, int res)
 {
 	io->flags |= (UBLKS_IO_NEED_COMMIT_RQ_COMP | UBLKS_IO_FREE);
 	io->result = res;
 }
 
-static inline const struct ublksrv_io_desc *ublk_get_iod(const struct ublk_queue *q, int tag)
+static inline const struct ublksrv_io_desc *ublk_get_iod(const struct ublk_queue *q, __u16 tag)
 {
-	return &q->io_cmd_buf[tag];
+	return (void *)q->io_cmd_buf + tag * (size_t)q->io_desc_size;
 }
 
 static inline void ublk_set_sqe_cmd_op(struct io_uring_sqe *sqe, __u32 cmd_op)
 {
 	__u32 *addr = (__u32 *)&sqe->off;
-- 
2.54.0