Commit d010fe26 authored by Darek Stojaczyk's avatar Darek Stojaczyk Committed by Jim Harris
Browse files

vhost: allow multiple sessions per device 



With all the patches in place, we can finally
enable having more than one simultaneous sessions
to a single vhost device.

This patch adds a unique id to the session structure,
similar to the one in a vhost device and also fills in
the implementation holes in foreach_session().

Vhost-NVMe can support only one session per device
and now has an additional check that prevents it from
starting more than one at a time.

Vhost-SCSI also has the same check now since it needs
additional work on the lcore assignment policy. The
check will be removed once the required work is done.

Change-Id: I13a32c7a0eae808e9bec63a7b8c15ec0bc2e36ed
Signed-off-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/439324


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarPawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
parent 14a6ca08

lib/vhost/vhost.c

+64 −19
Original line number Diff line number Diff line
@@ -52,6 +52,9 @@ struct spdk_vhost_session_fn_ctx { 
	/** Device pointer obtained before enqueuing the event */

	struct spdk_vhost_dev *vdev;



	/** ID of the session to send event to. */

	uint32_t vsession_id;



	/** User callback function to be executed on given lcore. */

	spdk_vhost_session_fn cb_fn;
@@ -505,14 +508,31 @@ spdk_vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec * 
	return 0;

}



static struct spdk_vhost_session *

spdk_vhost_session_find_by_id(struct spdk_vhost_dev *vdev, unsigned id)

{

	struct spdk_vhost_session *vsession;



	TAILQ_FOREACH(vsession, &vdev->vsessions, tailq) {

		if (vsession->id == id) {

			return vsession;

		}

	}



	return NULL;

}



static struct spdk_vhost_session *

spdk_vhost_session_find_by_vid(int vid)

{

	struct spdk_vhost_dev *vdev;

	struct spdk_vhost_session *vsession;



	TAILQ_FOREACH(vdev, &g_spdk_vhost_devices, tailq) {

		if (vdev->session && vdev->session->vid == vid) {

			return vdev->session;

		TAILQ_FOREACH(vsession, &vdev->vsessions, tailq) {

			if (vsession->vid == vid) {

				return vsession;

			}

		}

	}
@@ -735,7 +755,7 @@ spdk_vhost_dev_register(struct spdk_vhost_dev *vdev, const char *name, const cha 
	vdev->cpumask = cpumask;

	vdev->registered = true;

	vdev->backend = backend;



	TAILQ_INIT(&vdev->vsessions);

	spdk_vhost_set_coalescing(vdev, SPDK_VHOST_COALESCING_DELAY_BASE_US,

				  SPDK_VHOST_VQ_IOPS_COALESCING_THRESHOLD);
@@ -752,7 +772,7 @@ out: 
int

spdk_vhost_dev_unregister(struct spdk_vhost_dev *vdev)

{

	if (vdev->session) {

	if (!TAILQ_EMPTY(&vdev->vsessions)) {

		SPDK_ERRLOG("Controller %s has still valid connection.\n", vdev->name);

		return -EBUSY;

	}
@@ -776,7 +796,14 @@ spdk_vhost_dev_unregister(struct spdk_vhost_dev *vdev) 
static struct spdk_vhost_session *

spdk_vhost_session_next(struct spdk_vhost_dev *vdev, unsigned prev_id)

{

	/* so far there's only one session per device */

	struct spdk_vhost_session *vsession;



	TAILQ_FOREACH(vsession, &vdev->vsessions, tailq) {

		if (vsession->id > prev_id) {

			return vsession;

		}

	}



	return NULL;

}
@@ -831,8 +858,10 @@ static void 
spdk_vhost_event_cb(void *arg1, void *arg2)

{

	struct spdk_vhost_session_fn_ctx *ctx = arg1;

	struct spdk_vhost_session *vsession;



	ctx->cb_fn(ctx->vdev, ctx->vdev->session, ctx);

	vsession = spdk_vhost_session_find_by_id(ctx->vdev, ctx->vsession_id);

	ctx->cb_fn(ctx->vdev, vsession, ctx);

}



static void spdk_vhost_external_event_foreach_continue(struct spdk_vhost_dev *vdev,
@@ -855,8 +884,15 @@ spdk_vhost_event_async_foreach_fn(void *arg1, void *arg2) 
		return;

	}



	vsession = vdev->session;

	if (vsession != NULL && vsession->lcore >= 0 &&

	vsession = spdk_vhost_session_find_by_id(vdev, ctx->vsession_id);

	if (vsession == NULL) {

		/* The session must have been removed in the meantime, so we

		 * just skip it in our foreach chain

		 */

		goto out_unlock_continue;

	}



	if (vsession->lcore >= 0 &&

	    (uint32_t)vsession->lcore != spdk_env_get_current_core()) {

		/* if session has been relocated to other core, it is no longer thread-safe

		 * to access its contents here. Even though we're running under the global
@@ -875,8 +911,8 @@ spdk_vhost_event_async_foreach_fn(void *arg1, void *arg2) 
		goto out_unlock;

	}



	/* FIXME use a real session ID */

	vsession = spdk_vhost_session_next(vdev, -1);

out_unlock_continue:

	vsession = spdk_vhost_session_next(vdev, ctx->vsession_id);

	spdk_vhost_external_event_foreach_continue(vdev, vsession, ctx->cb_fn, arg2);

out_unlock:

	pthread_mutex_unlock(&g_spdk_vhost_mutex);
@@ -900,6 +936,7 @@ spdk_vhost_session_send_event(struct spdk_vhost_session *vsession, 
	}



	ev_ctx.vdev = vsession->vdev;

	ev_ctx.vsession_id = vsession->id;

	ev_ctx.cb_fn = cb_fn;

	ev = spdk_event_allocate(vsession->lcore, spdk_vhost_event_cb, &ev_ctx, NULL);

	assert(ev);
@@ -936,6 +973,7 @@ spdk_vhost_event_async_send_foreach_continue(struct spdk_vhost_session *vsession 
	}



	ev_ctx->vdev = vdev;

	ev_ctx->vsession_id = vsession->id;

	ev_ctx->cb_fn = cb_fn;



	ev = spdk_event_allocate(vsession->lcore,
@@ -1193,6 +1231,7 @@ new_connection(int vid) 
	char ifname[PATH_MAX];



	pthread_mutex_lock(&g_spdk_vhost_mutex);



	if (rte_vhost_get_ifname(vid, ifname, PATH_MAX) < 0) {

		SPDK_ERRLOG("Couldn't get a valid ifname for device with vid %d\n", vid);

		pthread_mutex_unlock(&g_spdk_vhost_mutex);
@@ -1206,10 +1245,14 @@ new_connection(int vid) 
		return -1;

	}



	if (vdev->session != NULL) {

		SPDK_ERRLOG("Device %s is already connected.\n", vdev->name);

		pthread_mutex_unlock(&g_spdk_vhost_mutex);

		return -1;

	/* We expect sessions inside vdev->vsessions to be sorted in ascending

	 * order in regard of vsession->id. For now we always set id = vsessions_cnt++

	 * and append each session to the very end of the vsessions list.

	 * This is required for spdk_vhost_dev_foreach_session() to work.

	 */

	if (vdev->vsessions_num == UINT_MAX) {

		assert(false);

		return -EINVAL;

	}



	vsession = spdk_dma_zmalloc(sizeof(struct spdk_vhost_session) +
@@ -1222,12 +1265,13 @@ new_connection(int vid) 
	}



	vsession->vdev = vdev;

	vsession->id = vdev->vsessions_num++;

	vsession->vid = vid;

	vsession->lcore = -1;

	vsession->next_stats_check_time = 0;

	vsession->stats_check_interval = SPDK_VHOST_STATS_CHECK_INTERVAL_MS *

					 spdk_get_ticks_hz() / 1000UL;

	vdev->session = vsession;

	TAILQ_INSERT_TAIL(&vdev->vsessions, vsession, tailq);

	pthread_mutex_unlock(&g_spdk_vhost_mutex);

	return 0;

}
@@ -1245,7 +1289,7 @@ destroy_connection(int vid) 
		return;

	}



	vsession->vdev->session = NULL;

	TAILQ_REMOVE(&vsession->vdev->vsessions, vsession, tailq);

	spdk_dma_free(vsession);

	pthread_mutex_unlock(&g_spdk_vhost_mutex);

}
@@ -1277,8 +1321,7 @@ spdk_vhost_external_event_foreach_continue(struct spdk_vhost_dev *vdev, 
		if (rc < 0) {

			return;

		}

		/* FIXME use a real session ID */

		vsession = spdk_vhost_session_next(vdev, -1);

		vsession = spdk_vhost_session_next(vdev, vsession->id);

		if (vsession == NULL) {

			goto out_finish_foreach;

		}
@@ -1300,9 +1343,11 @@ void 
spdk_vhost_dev_foreach_session(struct spdk_vhost_dev *vdev,

			       spdk_vhost_session_fn fn, void *arg)

{

	struct spdk_vhost_session *vsession = TAILQ_FIRST(&vdev->vsessions);



	assert(vdev->pending_async_op_num < UINT32_MAX);

	vdev->pending_async_op_num++;

	spdk_vhost_external_event_foreach_continue(vdev, vdev->session, fn, arg);

	spdk_vhost_external_event_foreach_continue(vdev, vsession, fn, arg);

}



void

lib/vhost/vhost_blk.c

+1 −1
Original line number Diff line number Diff line
@@ -410,7 +410,7 @@ process_vq(struct spdk_vhost_blk_session *bvsession, struct spdk_vhost_virtqueue 
{

	struct spdk_vhost_blk_dev *bvdev = bvsession->bvdev;

	struct spdk_vhost_blk_task *task;

	struct spdk_vhost_session *vsession = bvdev->vdev.session;

	struct spdk_vhost_session *vsession = &bvsession->vsession;

	int rc;

	uint16_t reqs[32];

	uint16_t reqs_cnt, i;

lib/vhost/vhost_internal.h

+10 −2
Original line number Diff line number Diff line
@@ -117,6 +117,9 @@ struct spdk_vhost_session { 
	/* rte_vhost connection ID. */

	int vid;



	/* Unique session ID. */

	unsigned id;



	int32_t lcore;



	struct rte_vhost_memory *mem;
@@ -138,6 +141,8 @@ struct spdk_vhost_session { 
	uint64_t stats_check_interval;



	struct spdk_vhost_virtqueue virtqueue[SPDK_VHOST_MAX_VQUEUES];



	TAILQ_ENTRY(spdk_vhost_session) tailq;

};



struct spdk_vhost_dev {
@@ -155,8 +160,11 @@ struct spdk_vhost_dev { 
	uint32_t coalescing_delay_us;

	uint32_t coalescing_iops_threshold;



	/* Current connection to the device */

	struct spdk_vhost_session *session;

	/* Current connections to the device */

	TAILQ_HEAD(, spdk_vhost_session) vsessions;



	/* Increment-only session counter */

	uint64_t vsessions_num;



	/* Number of started and actively polled sessions */

	uint32_t active_session_num;

lib/vhost/vhost_nvme.c

+14 −5
Original line number Diff line number Diff line
@@ -146,6 +146,9 @@ struct spdk_vhost_nvme_dev { 
	struct spdk_vhost_nvme_sq sq_queue[MAX_IO_QUEUES + 1];

	struct spdk_vhost_nvme_cq cq_queue[MAX_IO_QUEUES + 1];



	/* The one and only session associated with this device */

	struct spdk_vhost_session *vsession;



	TAILQ_ENTRY(spdk_vhost_nvme_dev) tailq;

	STAILQ_HEAD(, spdk_vhost_nvme_task) free_tasks;

	struct spdk_poller *requestq_poller;
@@ -248,7 +251,7 @@ static int 
spdk_nvme_map_prps(struct spdk_vhost_nvme_dev *nvme, struct spdk_nvme_cmd *cmd,

		   struct spdk_vhost_nvme_task *task, uint32_t len)

{

	struct spdk_vhost_session *vsession = nvme->vdev.session;

	struct spdk_vhost_session *vsession = nvme->vsession;

	uint64_t prp1, prp2;

	void *vva;

	uint32_t i;
@@ -699,7 +702,7 @@ static int 
vhost_nvme_doorbell_buffer_config(struct spdk_vhost_nvme_dev *nvme,

				  struct spdk_nvme_cmd *cmd, struct spdk_nvme_cpl *cpl)

{

	struct spdk_vhost_session *vsession = nvme->vdev.session;

	struct spdk_vhost_session *vsession = nvme->vsession;

	uint64_t dbs_dma_addr, eis_dma_addr;



	dbs_dma_addr = cmd->dptr.prp.prp1;
@@ -765,7 +768,7 @@ vhost_nvme_create_io_sq(struct spdk_vhost_nvme_dev *nvme, 
	sq->size = qsize + 1;

	sq->sq_head = sq->sq_tail = 0;

	requested_len = sizeof(struct spdk_nvme_cmd) * sq->size;

	sq->sq_cmd = spdk_vhost_gpa_to_vva(nvme->vdev.session, dma_addr, requested_len);

	sq->sq_cmd = spdk_vhost_gpa_to_vva(nvme->vsession, dma_addr, requested_len);

	if (!sq->sq_cmd) {

		return -1;

	}
@@ -848,7 +851,7 @@ vhost_nvme_create_io_cq(struct spdk_vhost_nvme_dev *nvme, 
	cq->guest_signaled_cq_head = 0;

	cq->need_signaled_cnt = 0;

	requested_len = sizeof(struct spdk_nvme_cpl) * cq->size;

	cq->cq_cqe = spdk_vhost_gpa_to_vva(nvme->vdev.session, dma_addr, requested_len);

	cq->cq_cqe = spdk_vhost_gpa_to_vva(nvme->vsession, dma_addr, requested_len);

	if (!cq->cq_cqe) {

		return -1;

	}
@@ -893,7 +896,7 @@ spdk_vhost_nvme_get_by_name(int vid) 
	struct spdk_vhost_nvme_dev *nvme;



	TAILQ_FOREACH(nvme, &g_nvme_ctrlrs, tailq) {

		if (nvme->vdev.session != NULL && nvme->vdev.session->vid == vid) {

		if (nvme->vsession != NULL && nvme->vsession->vid == vid) {

			return nvme;

		}

	}
@@ -1103,6 +1106,12 @@ spdk_vhost_nvme_start_cb(struct spdk_vhost_dev *vdev, 
static int

spdk_vhost_nvme_start(struct spdk_vhost_session *vsession)

{

	if (vsession->vdev->active_session_num > 0) {

		/* We're trying to start a second session */

		SPDK_ERRLOG("Vhost-NVMe devices can support only one simultaneous connection.\n");

		return -1;

	}



	return spdk_vhost_session_send_event(vsession, spdk_vhost_nvme_start_cb,

					     3, "start session");

}

lib/vhost/vhost_scsi.c

+7 −1
Original line number Diff line number Diff line
@@ -661,7 +661,7 @@ static void 
process_controlq(struct spdk_vhost_scsi_session *svsession, struct spdk_vhost_virtqueue *vq)

{

	struct spdk_vhost_scsi_dev *svdev = svsession->svdev;

	struct spdk_vhost_session *vsession = svdev->vdev.session;

	struct spdk_vhost_session *vsession = &svsession->vsession;

	struct spdk_vhost_scsi_task *task;

	uint16_t reqs[32];

	uint16_t reqs_cnt, i;
@@ -1266,6 +1266,12 @@ out: 
static int

spdk_vhost_scsi_start(struct spdk_vhost_session *vsession)

{

	if (vsession->vdev->active_session_num > 0) {

		/* We're trying to start a second session */

		SPDK_ERRLOG("Vhost-SCSI devices can support only one simultaneous connection.\n");

		return -1;

	}



	return spdk_vhost_session_send_event(vsession, spdk_vhost_scsi_start_cb,

					     3, "start session");

}