Commit 1e18d9cd authored by Darek Stojaczyk's avatar Darek Stojaczyk Committed by Jim Harris
Browse files

vhost: introduce spdk_vhost_dev_foreach_session 



When device is changed, e.g. the underlying bdev is
hotremoved, all sessions need to be notified. For
instance, Vhost-SCSI would send an additional hotremove
eventq message. That's why we introduce a helper
function to iterate through all active sessions.

Eventually, we may want to poll different sessions
from different lcores, so there will be some kind of
internal cross-lcore message management required
- just like there is one for spdk_vhost_call_external_event_foreach().
For now, though, we can get away with a dumbest
implementation.

We still want to keep this API internal for the time
being. The end-user (RPC) should only modify the
device, and the whole concept of sessions should be
completely encapsulated.

Change-Id: I2e142632c07a23daeac15cabea4cffecf984e455
Signed-off-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/418736


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 avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent f82a1757

lib/vhost/vhost.c

+15 −0
Original line number Diff line number Diff line
@@ -1349,6 +1349,21 @@ spdk_vhost_external_event_foreach_continue(struct spdk_vhost_dev *vdev, 
	spdk_vhost_event_async_send(vdev, fn, arg, true);

}



void

spdk_vhost_dev_foreach_session(struct spdk_vhost_dev *vdev,

			       spdk_vhost_session_fn fn, void *arg)

{

	int rc = 0;



	if (vdev->session != NULL) {

		rc = fn(vdev, vdev->session, arg);

	}



	if (rc >= 0) {

		fn(vdev, NULL, arg);

	}

}



void

spdk_vhost_call_external_event_foreach(spdk_vhost_event_fn fn, void *arg)

{

lib/vhost/vhost_internal.h

+31 −0
Original line number Diff line number Diff line
@@ -191,6 +191,25 @@ struct spdk_vhost_dev_destroy_ctx { 
	void *event_ctx;

};



/**

 * Synchronized vhost session event used for backend callbacks.

 *

 * \param vdev vhost device. If the device has been deleted

 * in the meantime, this function will be called one last

 * time with vdev == NULL.

 * \param vsession vhost session. If all sessions have been

 * iterated through, this function will be called one last

 * time with vsession == NULL.

 * \param arg user-provided parameter.

 *

 * \return negative values will break the foreach call, meaning

 * the function won't be called again. Return codes zero and

 * positive don't have any effect.

 */

typedef int (*spdk_vhost_session_fn)(struct spdk_vhost_dev *vdev,

				     struct spdk_vhost_session *vsession,

				     void *arg);



struct spdk_vhost_dev *spdk_vhost_dev_find(const char *ctrlr_name);



void *spdk_vhost_gpa_to_vva(struct spdk_vhost_session *vsession, uint64_t addr, uint64_t len);
@@ -272,6 +291,18 @@ int spdk_vhost_dev_unregister(struct spdk_vhost_dev *vdev); 
int spdk_vhost_scsi_controller_construct(void);

int spdk_vhost_blk_controller_construct(void);

void spdk_vhost_dump_info_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w);



/*

 * Call function for each active session on the provided

 * vhost device. The function will be called one-by-one

 * on each session's thread.

 *

 * \param vdev vhost device

 * \param fn function to call

 * \param arg additional argument to \c fn

 */

void spdk_vhost_dev_foreach_session(struct spdk_vhost_dev *dev,

				    spdk_vhost_session_fn fn, void *arg);

void spdk_vhost_dev_backend_event_done(void *event_ctx, int response);

void spdk_vhost_lock(void);

void spdk_vhost_unlock(void);