Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost cleanups and fixes from Michael Tsirkin:
 "Here are vhost cleanups and fixes by Asias He and myself.  They affect
  both vhost-net and vhost-scsi devices.  They also *depend* on both
  net-next and target-pending, where the net and target commits these
  changes depend on are already merged.  So merging through the common
  vhost tree."

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost_scsi: module rename
  tcm_vhost: header split up
  vhost: src file renames
  vhost: fix error handling in RESET_OWNER ioctl
  tcm_vhost: remove virtio-net.h dependency
  vhost: move per-vq net specific fields out to net
  tcm_vhost: document inflight ref-counting use
  vhost: move vhost-net zerocopy fields to net.c
  tcm_vhost: Wait for pending requests in vhost_scsi_flush()
  vhost: Allow device specific fields per vq

drivers/vhost/Kconfig

@@ -9,6 +9,10 @@ config VHOST_NET
 	  To compile this driver as a module, choose M here: the module will
 	  be called vhost_net.
 
-if STAGING
-source "drivers/vhost/Kconfig.tcm"
-endif
+config VHOST_SCSI
+	tristate "VHOST_SCSI TCM fabric driver"
+	depends on TARGET_CORE && EVENTFD && m
+	default n
+	---help---
+	Say M here to enable the vhost_scsi TCM fabric module
+	for use with virtio-scsi guests

drivers/vhost/Kconfig.tcm

-config TCM_VHOST
-	tristate "TCM_VHOST fabric module"
-	depends on TARGET_CORE && EVENTFD && m
-	default n
-	---help---
-	Say M here to enable the TCM_VHOST fabric module for use with virtio-scsi guests

drivers/vhost/Makefile

 obj-$(CONFIG_VHOST_NET) += vhost_net.o
 vhost_net-y := vhost.o net.o
 
-obj-$(CONFIG_TCM_VHOST) += tcm_vhost.o
+obj-$(CONFIG_VHOST_SCSI) += vhost_scsi.o
+vhost_scsi-y := scsi.o

drivers/vhost/tcm_vhost.h

-#define TCM_VHOST_VERSION  "v0.1"
-#define TCM_VHOST_NAMELEN 256
-#define TCM_VHOST_MAX_CDB_SIZE 32
-
-struct tcm_vhost_cmd {
-	/* Descriptor from vhost_get_vq_desc() for virt_queue segment */
-	int tvc_vq_desc;
-	/* virtio-scsi initiator task attribute */
-	int tvc_task_attr;
-	/* virtio-scsi initiator data direction */
-	enum dma_data_direction tvc_data_direction;
-	/* Expected data transfer length from virtio-scsi header */
-	u32 tvc_exp_data_len;
-	/* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
-	u64 tvc_tag;
-	/* The number of scatterlists associated with this cmd */
-	u32 tvc_sgl_count;
-	/* Saved unpacked SCSI LUN for tcm_vhost_submission_work() */
-	u32 tvc_lun;
-	/* Pointer to the SGL formatted memory from virtio-scsi */
-	struct scatterlist *tvc_sgl;
-	/* Pointer to response */
-	struct virtio_scsi_cmd_resp __user *tvc_resp;
-	/* Pointer to vhost_scsi for our device */
-	struct vhost_scsi *tvc_vhost;
-	/* Pointer to vhost_virtqueue for the cmd */
-	struct vhost_virtqueue *tvc_vq;
-	/* Pointer to vhost nexus memory */
-	struct tcm_vhost_nexus *tvc_nexus;
-	/* The TCM I/O descriptor that is accessed via container_of() */
-	struct se_cmd tvc_se_cmd;
-	/* work item used for cmwq dispatch to tcm_vhost_submission_work() */
-	struct work_struct work;
-	/* Copy of the incoming SCSI command descriptor block (CDB) */
-	unsigned char tvc_cdb[TCM_VHOST_MAX_CDB_SIZE];
-	/* Sense buffer that will be mapped into outgoing status */
-	unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
-	/* Completed commands list, serviced from vhost worker thread */
-	struct llist_node tvc_completion_list;
-};
-
-struct tcm_vhost_nexus {
-	/* Pointer to TCM session for I_T Nexus */
-	struct se_session *tvn_se_sess;
-};
-
-struct tcm_vhost_nacl {
-	/* Binary World Wide unique Port Name for Vhost Initiator port */
-	u64 iport_wwpn;
-	/* ASCII formatted WWPN for Sas Initiator port */
-	char iport_name[TCM_VHOST_NAMELEN];
-	/* Returned by tcm_vhost_make_nodeacl() */
-	struct se_node_acl se_node_acl;
-};
-
-struct vhost_scsi;
-struct tcm_vhost_tpg {
-	/* Vhost port target portal group tag for TCM */
-	u16 tport_tpgt;
-	/* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
-	int tv_tpg_port_count;
-	/* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
-	int tv_tpg_vhost_count;
-	/* list for tcm_vhost_list */
-	struct list_head tv_tpg_list;
-	/* Used to protect access for tpg_nexus */
-	struct mutex tv_tpg_mutex;
-	/* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
-	struct tcm_vhost_nexus *tpg_nexus;
-	/* Pointer back to tcm_vhost_tport */
-	struct tcm_vhost_tport *tport;
-	/* Returned by tcm_vhost_make_tpg() */
-	struct se_portal_group se_tpg;
-	/* Pointer back to vhost_scsi, protected by tv_tpg_mutex */
-	struct vhost_scsi *vhost_scsi;
-};
-
-struct tcm_vhost_tport {
-	/* SCSI protocol the tport is providing */
-	u8 tport_proto_id;
-	/* Binary World Wide unique Port Name for Vhost Target port */
-	u64 tport_wwpn;
-	/* ASCII formatted WWPN for Vhost Target port */
-	char tport_name[TCM_VHOST_NAMELEN];
-	/* Returned by tcm_vhost_make_tport() */
-	struct se_wwn tport_wwn;
-};
-
-struct tcm_vhost_evt {
-	/* event to be sent to guest */
-	struct virtio_scsi_event event;
-	/* event list, serviced from vhost worker thread */
-	struct llist_node list;
-};
-
-/*
- * As per request from MST, keep TCM_VHOST related ioctl defines out of
- * linux/vhost.h (user-space) for now..
- */
-
-#include <linux/vhost.h>
-
-/*
- * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
- *
- * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
- *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
- * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
- *            All the targets under vhost_wwpn can be seen and used by guset.
- */
-
-#define VHOST_SCSI_ABI_VERSION	1
-
-struct vhost_scsi_target {
-	int abi_version;
-	char vhost_wwpn[TRANSPORT_IQN_LEN];
-	unsigned short vhost_tpgt;
-	unsigned short reserved;
-};
-
-/* VHOST_SCSI specific defines */
-#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
-#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
-/* Changing this breaks userspace. */
-#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
-/* Set and get the events missed flag */
-#define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
-#define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)

drivers/vhost/test.c

@@ -219,13 +219,20 @@ static long vhost_test_reset_owner(struct vhost_test *n)
 {
 	void *priv = NULL;
 	long err;
+	struct vhost_memory *memory;
+
 	mutex_lock(&n->dev.mutex);
 	err = vhost_dev_check_owner(&n->dev);
 	if (err)
 		goto done;
+	memory = vhost_dev_reset_owner_prepare();
+	if (!memory) {
+		err = -ENOMEM;
+		goto done;
+	}
 	vhost_test_stop(n, &priv);
 	vhost_test_flush(n);
-	err = vhost_dev_reset_owner(&n->dev);
+	vhost_dev_reset_owner(&n->dev, memory);
 done:
 	mutex_unlock(&n->dev.mutex);
 	return err;

drivers/vhost/vhost.c

@@ -33,8 +33,6 @@ enum {
 	VHOST_MEMORY_F_LOG = 0x1,
 };
 
-static unsigned vhost_zcopy_mask __read_mostly;
-
 #define vhost_used_event(vq) ((u16 __user *)&vq->avail->ring[vq->num])
 #define vhost_avail_event(vq) ((u16 __user *)&vq->used->ring[vq->num])
 
@@ -181,8 +179,6 @@ static void vhost_vq_reset(struct vhost_dev *dev,
 	vq->used_flags = 0;
 	vq->log_used = false;
 	vq->log_addr = -1ull;
-	vq->vhost_hlen = 0;
-	vq->sock_hlen = 0;
 	vq->private_data = NULL;
 	vq->log_base = NULL;
 	vq->error_ctx = NULL;
@@ -191,9 +187,6 @@ static void vhost_vq_reset(struct vhost_dev *dev,
 	vq->call_ctx = NULL;
 	vq->call = NULL;
 	vq->log_ctx = NULL;
-	vq->upend_idx = 0;
-	vq->done_idx = 0;
-	vq->ubufs = NULL;
 }
 
 static int vhost_worker(void *data)
@@ -253,43 +246,29 @@ static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
 	vq->log = NULL;
 	kfree(vq->heads);
 	vq->heads = NULL;
-	kfree(vq->ubuf_info);
-	vq->ubuf_info = NULL;
-}
-
-void vhost_enable_zcopy(int vq)
-{
-	vhost_zcopy_mask |= 0x1 << vq;
 }
 
 /* Helper to allocate iovec buffers for all vqs. */
 static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
 {
 	int i;
-	bool zcopy;
 
 	for (i = 0; i < dev->nvqs; ++i) {
-		dev->vqs[i].indirect = kmalloc(sizeof *dev->vqs[i].indirect *
+		dev->vqs[i]->indirect = kmalloc(sizeof *dev->vqs[i]->indirect *
 					       UIO_MAXIOV, GFP_KERNEL);
-		dev->vqs[i].log = kmalloc(sizeof *dev->vqs[i].log * UIO_MAXIOV,
+		dev->vqs[i]->log = kmalloc(sizeof *dev->vqs[i]->log * UIO_MAXIOV,
 					  GFP_KERNEL);
-		dev->vqs[i].heads = kmalloc(sizeof *dev->vqs[i].heads *
+		dev->vqs[i]->heads = kmalloc(sizeof *dev->vqs[i]->heads *
 					    UIO_MAXIOV, GFP_KERNEL);
-		zcopy = vhost_zcopy_mask & (0x1 << i);
-		if (zcopy)
-			dev->vqs[i].ubuf_info =
-				kmalloc(sizeof *dev->vqs[i].ubuf_info *
-					UIO_MAXIOV, GFP_KERNEL);
-		if (!dev->vqs[i].indirect || !dev->vqs[i].log ||
-			!dev->vqs[i].heads ||
-			(zcopy && !dev->vqs[i].ubuf_info))
+		if (!dev->vqs[i]->indirect || !dev->vqs[i]->log ||
+			!dev->vqs[i]->heads)
 			goto err_nomem;
 	}
 	return 0;
 
 err_nomem:
 	for (; i >= 0; --i)
-		vhost_vq_free_iovecs(&dev->vqs[i]);
+		vhost_vq_free_iovecs(dev->vqs[i]);
 	return -ENOMEM;
 }
 
@@ -298,11 +277,11 @@ static void vhost_dev_free_iovecs(struct vhost_dev *dev)
 	int i;
 
 	for (i = 0; i < dev->nvqs; ++i)
-		vhost_vq_free_iovecs(&dev->vqs[i]);
+		vhost_vq_free_iovecs(dev->vqs[i]);
 }
 
 long vhost_dev_init(struct vhost_dev *dev,
-		    struct vhost_virtqueue *vqs, int nvqs)
+		    struct vhost_virtqueue **vqs, int nvqs)
 {
 	int i;
 
@@ -318,16 +297,15 @@ long vhost_dev_init(struct vhost_dev *dev,
 	dev->worker = NULL;
 
 	for (i = 0; i < dev->nvqs; ++i) {
-		dev->vqs[i].log = NULL;
-		dev->vqs[i].indirect = NULL;
-		dev->vqs[i].heads = NULL;
-		dev->vqs[i].ubuf_info = NULL;
-		dev->vqs[i].dev = dev;
-		mutex_init(&dev->vqs[i].mutex);
-		vhost_vq_reset(dev, dev->vqs + i);
-		if (dev->vqs[i].handle_kick)
-			vhost_poll_init(&dev->vqs[i].poll,
-					dev->vqs[i].handle_kick, POLLIN, dev);
+		dev->vqs[i]->log = NULL;
+		dev->vqs[i]->indirect = NULL;
+		dev->vqs[i]->heads = NULL;
+		dev->vqs[i]->dev = dev;
+		mutex_init(&dev->vqs[i]->mutex);
+		vhost_vq_reset(dev, dev->vqs[i]);
+		if (dev->vqs[i]->handle_kick)
+			vhost_poll_init(&dev->vqs[i]->poll,
+					dev->vqs[i]->handle_kick, POLLIN, dev);
 	}
 
 	return 0;
@@ -408,21 +386,19 @@ static long vhost_dev_set_owner(struct vhost_dev *dev)
 	return err;
 }
 
-/* Caller should have device mutex */
-long vhost_dev_reset_owner(struct vhost_dev *dev)
+struct vhost_memory *vhost_dev_reset_owner_prepare(void)
 {
-	struct vhost_memory *memory;
-
-	/* Restore memory to default empty mapping. */
-	memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
-	if (!memory)
-		return -ENOMEM;
+	return kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
+}
 
+/* Caller should have device mutex */
+void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_memory *memory)
+{
 	vhost_dev_cleanup(dev, true);
 
+	/* Restore memory to default empty mapping. */
 	memory->nregions = 0;
 	RCU_INIT_POINTER(dev->memory, memory);
-	return 0;
 }
 
 void vhost_dev_stop(struct vhost_dev *dev)
@@ -430,9 +406,9 @@ void vhost_dev_stop(struct vhost_dev *dev)
 	int i;
 
 	for (i = 0; i < dev->nvqs; ++i) {
-		if (dev->vqs[i].kick && dev->vqs[i].handle_kick) {
-			vhost_poll_stop(&dev->vqs[i].poll);
-			vhost_poll_flush(&dev->vqs[i].poll);
+		if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) {
+			vhost_poll_stop(&dev->vqs[i]->poll);
+			vhost_poll_flush(&dev->vqs[i]->poll);
 		}
 	}
 }
@@ -443,17 +419,17 @@ void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
 	int i;
 
 	for (i = 0; i < dev->nvqs; ++i) {
-		if (dev->vqs[i].error_ctx)
-			eventfd_ctx_put(dev->vqs[i].error_ctx);
-		if (dev->vqs[i].error)
-			fput(dev->vqs[i].error);
-		if (dev->vqs[i].kick)
-			fput(dev->vqs[i].kick);
-		if (dev->vqs[i].call_ctx)
-			eventfd_ctx_put(dev->vqs[i].call_ctx);
-		if (dev->vqs[i].call)
-			fput(dev->vqs[i].call);
-		vhost_vq_reset(dev, dev->vqs + i);
+		if (dev->vqs[i]->error_ctx)
+			eventfd_ctx_put(dev->vqs[i]->error_ctx);
+		if (dev->vqs[i]->error)
+			fput(dev->vqs[i]->error);
+		if (dev->vqs[i]->kick)
+			fput(dev->vqs[i]->kick);
+		if (dev->vqs[i]->call_ctx)
+			eventfd_ctx_put(dev->vqs[i]->call_ctx);
+		if (dev->vqs[i]->call)
+			fput(dev->vqs[i]->call);
+		vhost_vq_reset(dev, dev->vqs[i]);
 	}
 	vhost_dev_free_iovecs(dev);
 	if (dev->log_ctx)
@@ -524,14 +500,14 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem,
 
 	for (i = 0; i < d->nvqs; ++i) {
 		int ok;
-		mutex_lock(&d->vqs[i].mutex);
+		mutex_lock(&d->vqs[i]->mutex);
 		/* If ring is inactive, will check when it's enabled. */
-		if (d->vqs[i].private_data)
-			ok = vq_memory_access_ok(d->vqs[i].log_base, mem,
+		if (d->vqs[i]->private_data)
+			ok = vq_memory_access_ok(d->vqs[i]->log_base, mem,
 						 log_all);
 		else
 			ok = 1;
-		mutex_unlock(&d->vqs[i].mutex);
+		mutex_unlock(&d->vqs[i]->mutex);
 		if (!ok)
 			return 0;
 	}
@@ -641,7 +617,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
 	if (idx >= d->nvqs)
 		return -ENOBUFS;
 
-	vq = d->vqs + idx;
+	vq = d->vqs[idx];
 
 	mutex_lock(&vq->mutex);
 
@@ -852,7 +828,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
 		for (i = 0; i < d->nvqs; ++i) {
 			struct vhost_virtqueue *vq;
 			void __user *base = (void __user *)(unsigned long)p;
-			vq = d->vqs + i;
+			vq = d->vqs[i];
 			mutex_lock(&vq->mutex);
 			/* If ring is inactive, will check when it's enabled. */
 			if (vq->private_data && !vq_log_access_ok(d, vq, base))
@@ -879,9 +855,9 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
 		} else
 			filep = eventfp;
 		for (i = 0; i < d->nvqs; ++i) {
-			mutex_lock(&d->vqs[i].mutex);
-			d->vqs[i].log_ctx = d->log_ctx;
-			mutex_unlock(&d->vqs[i].mutex);
+			mutex_lock(&d->vqs[i]->mutex);
+			d->vqs[i]->log_ctx = d->log_ctx;
+			mutex_unlock(&d->vqs[i]->mutex);
 		}
 		if (ctx)
 			eventfd_ctx_put(ctx);
@@ -1551,38 +1527,3 @@ void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 			       &vq->used->flags, r);
 	}
 }
-
-static void vhost_zerocopy_done_signal(struct kref *kref)
-{
-	struct vhost_ubuf_ref *ubufs = container_of(kref, struct vhost_ubuf_ref,
-						    kref);
-	wake_up(&ubufs->wait);
-}
-
-struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *vq,
-					bool zcopy)
-{
-	struct vhost_ubuf_ref *ubufs;
-	/* No zero copy backend? Nothing to count. */
-	if (!zcopy)
-		return NULL;
-	ubufs = kmalloc(sizeof *ubufs, GFP_KERNEL);
-	if (!ubufs)
-		return ERR_PTR(-ENOMEM);
-	kref_init(&ubufs->kref);
-	init_waitqueue_head(&ubufs->wait);
-	ubufs->vq = vq;
-	return ubufs;
-}
-
-void vhost_ubuf_put(struct vhost_ubuf_ref *ubufs)
-{
-	kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
-}
-
-void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs)
-{
-	kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
-	wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
-	kfree(ubufs);
-}

drivers/vhost/vhost.h

@@ -54,18 +54,6 @@ struct vhost_log {
 
 struct vhost_virtqueue;
 
-struct vhost_ubuf_ref {
-	struct kref kref;
-	wait_queue_head_t wait;
-	struct vhost_virtqueue *vq;
-};
-
-struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy);
-void vhost_ubuf_put(struct vhost_ubuf_ref *);
-void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);
-
-struct ubuf_info;
-
 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
 	struct vhost_dev *dev;
@@ -114,10 +102,7 @@ struct vhost_virtqueue {
 	/* hdr is used to store the virtio header.
 	 * Since each iovec has >= 1 byte length, we never need more than
 	 * header length entries to store the header. */
-	struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
 	struct iovec *indirect;
-	size_t vhost_hlen;
-	size_t sock_hlen;
 	struct vring_used_elem *heads;
 	/* We use a kind of RCU to access private pointer.
 	 * All readers access it from worker, which makes it possible to
@@ -130,16 +115,6 @@ struct vhost_virtqueue {
 	/* Log write descriptors */
 	void __user *log_base;
 	struct vhost_log *log;
-	/* vhost zerocopy support fields below: */
-	/* last used idx for outstanding DMA zerocopy buffers */
-	int upend_idx;
-	/* first used idx for DMA done zerocopy buffers */
-	int done_idx;
-	/* an array of userspace buffers info */
-	struct ubuf_info *ubuf_info;
-	/* Reference counting for outstanding ubufs.
-	 * Protected by vq mutex. Writers must also take device mutex. */
-	struct vhost_ubuf_ref *ubufs;
 };
 
 struct vhost_dev {
@@ -150,7 +125,7 @@ struct vhost_dev {
 	struct mm_struct *mm;
 	struct mutex mutex;
 	unsigned acked_features;
-	struct vhost_virtqueue *vqs;
+	struct vhost_virtqueue **vqs;
 	int nvqs;
 	struct file *log_file;
 	struct eventfd_ctx *log_ctx;
@@ -159,9 +134,10 @@ struct vhost_dev {
 	struct task_struct *worker;
 };
 
-long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
+long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
 long vhost_dev_check_owner(struct vhost_dev *);
-long vhost_dev_reset_owner(struct vhost_dev *);
+struct vhost_memory *vhost_dev_reset_owner_prepare(void);
+void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
 void vhost_dev_cleanup(struct vhost_dev *, bool locked);
 void vhost_dev_stop(struct vhost_dev *);
 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);

include/uapi/linux/vhost.h

@@ -127,4 +127,32 @@ struct vhost_memory {
 /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
 #define VHOST_NET_F_VIRTIO_NET_HDR 27
 
+/* VHOST_SCSI specific definitions */
+
+/*
+ * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
+ *
+ * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
+ *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
+ * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
+ *            All the targets under vhost_wwpn can be seen and used by guset.
+ */
+
+#define VHOST_SCSI_ABI_VERSION	1
+
+struct vhost_scsi_target {
+	int abi_version;
+	char vhost_wwpn[224]; /* TRANSPORT_IQN_LEN */
+	unsigned short vhost_tpgt;
+	unsigned short reserved;
+};
+
+#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
+#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
+/* Changing this breaks userspace. */
+#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
+/* Set and get the events missed flag */
+#define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
+#define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
+
 #endif