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Commit 67e18cf9 authored by Asias He's avatar Asias He Committed by Nicholas Bellinger
Browse files

tcm_vhost: Multi-target support 



In order to take advantages of Paolo's multi-queue virito-scsi, we need
multi-target support in tcm_vhost first. Otherwise all the requests go
to one queue and other queues are idle.

This patch makes:

1. All the targets under the wwpn is seen and can be used by guest.
2. No need to pass the tpgt number in struct vhost_scsi_target to
   tcm_vhost.ko. Only wwpn is needed.
3. We can always pass max_target = 255 to guest now, since we abort the
   request who's target id does not exist.

Changes in v2:
- Handle non-contiguous tpgt

Changes in v3:
- Simplfy lock in vhost_scsi_set_endpoint
- Return -EEXIST when does not match

Signed-off-by: default avatarAsias He <asias@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent adfa9570

drivers/vhost/tcm_vhost.c

+82 −49
Original line number Diff line number Diff line
@@ -59,8 +59,14 @@ enum { 
	VHOST_SCSI_VQ_IO = 2,

};



#define VHOST_SCSI_MAX_TARGET 256



struct vhost_scsi {

	struct tcm_vhost_tpg *vs_tpg;	/* Protected by vhost_scsi->dev.mutex */

	/* Protected by vhost_scsi->dev.mutex */

	struct tcm_vhost_tpg *vs_tpg[VHOST_SCSI_MAX_TARGET];

	char vs_vhost_wwpn[TRANSPORT_IQN_LEN];

	bool vs_endpoint;



	struct vhost_dev dev;

	struct vhost_virtqueue vqs[3];
@@ -564,10 +570,10 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs) 
	u32 exp_data_len, data_first, data_num, data_direction;

	unsigned out, in, i;

	int head, ret;

	u8 target;



	/* Must use ioctl VHOST_SCSI_SET_ENDPOINT */

	tv_tpg = vs->vs_tpg;

	if (unlikely(!tv_tpg))

	if (unlikely(!vs->vs_endpoint))

		return;



	mutex_lock(&vq->mutex);
@@ -635,6 +641,28 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs) 
			break;

		}



		/* Extract the tpgt */

		target = v_req.lun[1];

		tv_tpg = vs->vs_tpg[target];



		/* Target does not exist, fail the request */

		if (unlikely(!tv_tpg)) {

			struct virtio_scsi_cmd_resp __user *resp;

			struct virtio_scsi_cmd_resp rsp;



			memset(&rsp, 0, sizeof(rsp));

			rsp.response = VIRTIO_SCSI_S_BAD_TARGET;

			resp = vq->iov[out].iov_base;

			ret = __copy_to_user(resp, &rsp, sizeof(rsp));

			if (!ret)

				vhost_add_used_and_signal(&vs->dev,

						&vs->vqs[2], head, 0);

			else

				pr_err("Faulted on virtio_scsi_cmd_resp\n");



			continue;

		}



		exp_data_len = 0;

		for (i = 0; i < data_num; i++)

			exp_data_len += vq->iov[data_first + i].iov_len;
@@ -743,7 +771,8 @@ static int vhost_scsi_set_endpoint( 
{

	struct tcm_vhost_tport *tv_tport;

	struct tcm_vhost_tpg *tv_tpg;

	int index;

	bool match = false;

	int index, ret;



	mutex_lock(&vs->dev.mutex);

	/* Verify that ring has been setup correctly. */
@@ -754,7 +783,6 @@ static int vhost_scsi_set_endpoint( 
			return -EFAULT;

		}

	}

	mutex_unlock(&vs->dev.mutex);



	mutex_lock(&tcm_vhost_mutex);

	list_for_each_entry(tv_tpg, &tcm_vhost_list, tv_tpg_list) {
@@ -769,30 +797,33 @@ static int vhost_scsi_set_endpoint( 
		}

		tv_tport = tv_tpg->tport;



		if (!strcmp(tv_tport->tport_name, t->vhost_wwpn) &&

		    (tv_tpg->tport_tpgt == t->vhost_tpgt)) {

			tv_tpg->tv_tpg_vhost_count++;

		if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {

			if (vs->vs_tpg[tv_tpg->tport_tpgt]) {

				mutex_unlock(&tv_tpg->tv_tpg_mutex);

				mutex_unlock(&tcm_vhost_mutex);



			mutex_lock(&vs->dev.mutex);

			if (vs->vs_tpg) {

				mutex_unlock(&vs->dev.mutex);

				mutex_lock(&tv_tpg->tv_tpg_mutex);

				tv_tpg->tv_tpg_vhost_count--;

				mutex_unlock(&tv_tpg->tv_tpg_mutex);

				return -EEXIST;

			}



			vs->vs_tpg = tv_tpg;

			tv_tpg->tv_tpg_vhost_count++;

			vs->vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;

			smp_mb__after_atomic_inc();

			mutex_unlock(&vs->dev.mutex);

			return 0;

			match = true;

		}

		mutex_unlock(&tv_tpg->tv_tpg_mutex);

	}

	mutex_unlock(&tcm_vhost_mutex);

	return -EINVAL;



	if (match) {

		memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,

		       sizeof(vs->vs_vhost_wwpn));

		vs->vs_endpoint = true;

		ret = 0;

	} else {

		ret = -EEXIST;

	}



	mutex_unlock(&vs->dev.mutex);

	return ret;

}



static int vhost_scsi_clear_endpoint(
@@ -801,7 +832,8 @@ static int vhost_scsi_clear_endpoint( 
{

	struct tcm_vhost_tport *tv_tport;

	struct tcm_vhost_tpg *tv_tpg;

	int index, ret;

	int index, ret, i;

	u8 target;



	mutex_lock(&vs->dev.mutex);

	/* Verify that ring has been setup correctly. */
@@ -811,16 +843,20 @@ static int vhost_scsi_clear_endpoint( 
			goto err;

		}

	}

	for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {

		target = i;



	if (!vs->vs_tpg) {

		tv_tpg = vs->vs_tpg[target];

		if (!tv_tpg)

			continue;



		tv_tport = tv_tpg->tport;

		if (!tv_tport) {

			ret = -ENODEV;

			goto err;

		}

	tv_tpg = vs->vs_tpg;

	tv_tport = tv_tpg->tport;



	if (strcmp(tv_tport->tport_name, t->vhost_wwpn) ||

	    (tv_tpg->tport_tpgt != t->vhost_tpgt)) {

		if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {

			pr_warn("tv_tport->tport_name: %s, tv_tpg->tport_tpgt: %hu"

				" does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",

				tv_tport->tport_name, tv_tpg->tport_tpgt,
@@ -829,9 +865,10 @@ static int vhost_scsi_clear_endpoint( 
			goto err;

		}

		tv_tpg->tv_tpg_vhost_count--;

	vs->vs_tpg = NULL;

		vs->vs_tpg[target] = NULL;

		vs->vs_endpoint = false;

	}

	mutex_unlock(&vs->dev.mutex);



	return 0;



err:
@@ -866,16 +903,12 @@ static int vhost_scsi_open(struct inode *inode, struct file *f) 
static int vhost_scsi_release(struct inode *inode, struct file *f)

{

	struct vhost_scsi *s = f->private_data;

	struct vhost_scsi_target t;



	if (s->vs_tpg && s->vs_tpg->tport) {

		struct vhost_scsi_target backend;



		memcpy(backend.vhost_wwpn, s->vs_tpg->tport->tport_name,

				sizeof(backend.vhost_wwpn));

		backend.vhost_tpgt = s->vs_tpg->tport_tpgt;

		vhost_scsi_clear_endpoint(s, &backend);

	}



	mutex_lock(&s->dev.mutex);

	memcpy(t.vhost_wwpn, s->vs_vhost_wwpn, sizeof(t.vhost_wwpn));

	mutex_unlock(&s->dev.mutex);

	vhost_scsi_clear_endpoint(s, &t);

	vhost_dev_stop(&s->dev);

	vhost_dev_cleanup(&s->dev, false);

	kfree(s);

drivers/vhost/tcm_vhost.h

+3 −1
Original line number Diff line number Diff line
@@ -93,9 +93,11 @@ struct tcm_vhost_tport { 
 *

 * 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	0

#define VHOST_SCSI_ABI_VERSION	1



struct vhost_scsi_target {

	int abi_version;