vhost: don't expose backend structures outside backend implementation

Theres no need to have vhost SCSI (and incoming vhost block) structures
available in public API. Generic spdk_vhost_dev might be used to
communicate with backedns. Backends are responsible to check if type of
passed vdev valid.

Change-Id: I850a1cc661166ee146d513b0069bb40edc9a761a
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-on: https://review.gerrithub.io/363581
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

include/spdk/vhost.h

@@ -51,7 +51,6 @@ void spdk_vhost_shutdown_cb(void);
 
 /* Forward declaration */
 struct spdk_vhost_dev;
-struct spdk_vhost_scsi_dev;
 
 /**
  * Get handle to next controller.
@@ -64,4 +63,13 @@ const char *spdk_vhost_dev_get_name(struct spdk_vhost_dev *ctrl);
 uint64_t spdk_vhost_dev_get_cpumask(struct spdk_vhost_dev *ctrl);
 int spdk_vhost_parse_core_mask(const char *mask, uint64_t *cpumask);
 
+int spdk_vhost_scsi_controller_construct(void);
+int spdk_vhost_scsi_dev_construct(const char *name, uint64_t cpumask);
+int spdk_vhost_scsi_dev_remove(struct spdk_vhost_dev *vdev);
+struct spdk_scsi_dev *spdk_vhost_scsi_dev_get_dev(struct spdk_vhost_dev *ctrl,
+		uint8_t num);
+int spdk_vhost_scsi_dev_add_dev(const char *name, unsigned scsi_dev_num, const char *lun_name);
+int spdk_vhost_scsi_dev_remove_dev(struct spdk_vhost_dev *vdev, unsigned scsi_dev_num);
+
+
 #endif /* SPDK_VHOST_H */

lib/vhost/vhost.c

@@ -39,7 +39,6 @@
 
 #include "spdk/vhost.h"
 #include "vhost_internal.h"
-#include "vhost_scsi.h"
 #include "task.h"
 #include "vhost_iommu.h"
 

lib/vhost/vhost_internal.h

@@ -53,6 +53,8 @@
 
 #define MAX_VHOST_VRINGS	256
 
+#define SPDK_VHOST_SCSI_CTRLR_MAX_DEVS 8
+
 enum spdk_vhost_dev_type {
 	SPDK_VHOST_DEV_T_SCSI,
 };

lib/vhost/vhost_rpc.c

@@ -32,14 +32,13 @@
  */
 
 #include "spdk/stdinc.h"
-
 #include "spdk_internal/log.h"
 #include "spdk/rpc.h"
 #include "spdk/util.h"
 
-#include "vhost_scsi.h"
 #include "spdk/vhost.h"
 #include "task.h"
+#include "vhost_internal.h"
 
 static void
 json_scsi_dev_write(struct spdk_json_write_ctx *ctx, struct spdk_scsi_dev *dev)
@@ -108,7 +107,7 @@ spdk_rpc_get_vhost_scsi_controllers(struct spdk_jsonrpc_server_conn *conn,
 		spdk_json_write_array_begin(w);
 
 		for (i = 0; i < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; i++) {
-			dev = spdk_vhost_scsi_dev_get_dev((struct spdk_vhost_scsi_dev *) vdev, i);
+			dev = spdk_vhost_scsi_dev_get_dev(vdev, i);
 			if (!dev)
 				continue;
 
@@ -224,7 +223,7 @@ spdk_rpc_remove_vhost_scsi_controller(struct spdk_jsonrpc_server_conn *conn,
 		goto invalid;
 	}
 
-	rc = spdk_vhost_scsi_dev_remove((struct spdk_vhost_scsi_dev *) vdev);
+	rc = spdk_vhost_scsi_dev_remove(vdev);
 	if (rc < 0) {
 		goto invalid;
 	}
@@ -340,7 +339,7 @@ spdk_rpc_remove_vhost_scsi_dev(struct spdk_jsonrpc_server_conn *conn,
 		goto invalid;
 	}
 
-	rc = spdk_vhost_scsi_dev_remove_dev((struct spdk_vhost_scsi_dev *) vdev, req.scsi_dev_num);
+	rc = spdk_vhost_scsi_dev_remove_dev(vdev, req.scsi_dev_num);
 	if (rc < 0) {
 		goto invalid;
 	}

lib/vhost/vhost_scsi.c

@@ -37,12 +37,12 @@
 
 #include "spdk/env.h"
 #include "spdk/scsi.h"
+#include "spdk/scsi_spec.h"
 #include "spdk/conf.h"
 #include "spdk/event.h"
 
 #include "spdk/vhost.h"
 #include "vhost_internal.h"
-#include "vhost_scsi.h"
 #include "task.h"
 
 /* Features supported by SPDK VHOST lib. */
@@ -566,6 +566,22 @@ remove_vdev_cb(void *arg)
 	spdk_vhost_dev_mem_unregister(&svdev->vdev);
 }
 
+static struct spdk_vhost_scsi_dev *
+to_scsi_dev(struct spdk_vhost_dev *ctrlr)
+{
+	if (ctrlr == NULL) {
+		return NULL;
+	}
+
+	if (ctrlr->type != SPDK_VHOST_DEV_T_SCSI) {
+		SPDK_ERRLOG("Controller %s: expected SCSI controller (%d) but got %d\n",
+			    ctrlr->name, SPDK_VHOST_DEV_T_SCSI, ctrlr->type);
+		return NULL;
+	}
+
+	return (struct spdk_vhost_scsi_dev *)ctrlr;
+}
+
 int
 spdk_vhost_scsi_dev_construct(const char *name, uint64_t cpumask)
 {
@@ -588,12 +604,15 @@ spdk_vhost_scsi_dev_construct(const char *name, uint64_t cpumask)
 }
 
 int
-spdk_vhost_scsi_dev_remove(struct spdk_vhost_scsi_dev *svdev)
+spdk_vhost_scsi_dev_remove(struct spdk_vhost_dev *vdev)
 {
-	struct spdk_vhost_dev *vdev;
+	struct spdk_vhost_scsi_dev *svdev = to_scsi_dev(vdev);
 	int i;
 
-	vdev = &svdev->vdev;
+	if (svdev == NULL) {
+		return -EINVAL;
+	}
+
 	for (i = 0; i < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; ++i) {
 		if (svdev->scsi_dev[i]) {
 			SPDK_ERRLOG("Trying to remove non-empty controller: %s.\n", vdev->name);
@@ -610,11 +629,14 @@ spdk_vhost_scsi_dev_remove(struct spdk_vhost_scsi_dev *svdev)
 }
 
 struct spdk_scsi_dev *
-spdk_vhost_scsi_dev_get_dev(struct spdk_vhost_scsi_dev *svdev, uint8_t num)
+spdk_vhost_scsi_dev_get_dev(struct spdk_vhost_dev *vdev, uint8_t num)
 {
-	assert(svdev != NULL);
+	struct spdk_vhost_scsi_dev *svdev;
+
 	assert(num < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS);
-	return svdev->scsi_dev[num];
+	svdev = to_scsi_dev(vdev);
+
+	return svdev ? svdev->scsi_dev[num] : NULL;
 }
 
 int
@@ -645,13 +667,16 @@ spdk_vhost_scsi_dev_add_dev(const char *ctrlr_name, unsigned scsi_dev_num, const
 		return -1;
 	}
 
-	svdev = (struct spdk_vhost_scsi_dev *) spdk_vhost_dev_find(ctrlr_name);
+	vdev = spdk_vhost_dev_find(ctrlr_name);
-	if (svdev == NULL) {
+	if (vdev == NULL) {
-		SPDK_ERRLOG("Controller %s is not defined\n", ctrlr_name);
+		SPDK_ERRLOG("Controller %s is not defined.\n", ctrlr_name);
 		return -ENODEV;
 	}
 
-	vdev = &svdev->vdev;
+	svdev = to_scsi_dev(vdev);
+	if (svdev == NULL) {
+		return -EINVAL;
+	}
 
 	if (vdev->lcore != -1) {
 		SPDK_ERRLOG("Controller %s is in use and hotplug is not supported\n", ctrlr_name);
@@ -686,15 +711,21 @@ spdk_vhost_scsi_dev_add_dev(const char *ctrlr_name, unsigned scsi_dev_num, const
 }
 
 int
-spdk_vhost_scsi_dev_remove_dev(struct spdk_vhost_scsi_dev *svdev, unsigned scsi_dev_num)
+spdk_vhost_scsi_dev_remove_dev(struct spdk_vhost_dev *vdev, unsigned scsi_dev_num)
 {
-	struct spdk_vhost_dev *vdev = &svdev->vdev;
+	struct spdk_vhost_scsi_dev *svdev;
 
+	assert(vdev != NULL);
 	if (vdev->lcore != -1) {
 		SPDK_ERRLOG("Controller %s is in use and hotremove is not supported\n", vdev->name);
 		return -EBUSY;
 	}
 
+	svdev = to_scsi_dev(vdev);
+	if (svdev == NULL) {
+		return -ENODEV;
+	}
+
 	if (svdev->scsi_dev[scsi_dev_num] == NULL) {
 		SPDK_ERRLOG("Controller %s dev %u is not occupied\n", vdev->name, scsi_dev_num);
 		return -ENODEV;
@@ -803,7 +834,8 @@ destroy_device(int vid)
 	if (vdev == NULL) {
 		rte_panic("Couldn't find device with vid %d to stop.\n", vid);
 	}
-	svdev = (struct spdk_vhost_scsi_dev *) vdev;
+	svdev = to_scsi_dev(vdev);
+	assert(svdev);
 
 	spdk_vhost_timed_event_init(&event, vdev->lcore, NULL, NULL, 1);
 	spdk_poller_unregister(&svdev->requestq_poller, event.spdk_event);

lib/vhost/vhost_scsi.h

@@ -1,51 +0,0 @@
-/*-
- *   BSD LICENSE
- *
- *   Copyright (c) Intel Corporation.
- *   All rights reserved.
- *
- *   Redistribution and use in source and binary forms, with or without
- *   modification, are permitted provided that the following conditions
- *   are met:
- *
- *     * Redistributions of source code must retain the above copyright
- *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in
- *       the documentation and/or other materials provided with the
- *       distribution.
- *     * Neither the name of Intel Corporation nor the names of its
- *       contributors may be used to endorse or promote products derived
- *       from this software without specific prior written permission.
- *
- *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef SPDK_VHOST_SCSI_H
-#define SPDK_VHOST_SCSI_H
-
-#include "spdk/scsi_spec.h"
-
-#define SPDK_VHOST_SCSI_CTRLR_MAX_DEVS 8
-
-struct spdk_vhost_scsi_dev;
-
-int spdk_vhost_scsi_controller_construct(void);
-int spdk_vhost_scsi_dev_construct(const char *name, uint64_t cpumask);
-int spdk_vhost_scsi_dev_remove(struct spdk_vhost_scsi_dev *vdev);
-struct spdk_scsi_dev *spdk_vhost_scsi_dev_get_dev(struct spdk_vhost_scsi_dev *ctrl,
-		uint8_t num);
-int spdk_vhost_scsi_dev_add_dev(const char *name, unsigned scsi_dev_num, const char *lun_name);
-int spdk_vhost_scsi_dev_remove_dev(struct spdk_vhost_scsi_dev *vdev, unsigned scsi_dev_num);
-
-#endif /* SPDK_VHOST_SCSI_H */