[PATCH] tcm_vhost: Multi-target support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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.

Signed-off-by: Asias He <asias@xxxxxxxxxx>
---
 drivers/vhost/tcm_vhost.c | 115 ++++++++++++++++++++++++++++------------------
 drivers/vhost/tcm_vhost.h |   4 +-
 2 files changed, 74 insertions(+), 45 deletions(-)

diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index 218deb6..d50cb95 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -59,13 +59,18 @@ 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];
 	struct vhost_dev dev;
 	struct vhost_virtqueue vqs[3];
 
 	struct vhost_work vs_completion_work; /* cmd completion work item */
 	struct llist_head vs_completion_list; /* cmd completion queue */
+	char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
+	int vs_num_target;
 };
 
 /* Local pointer to allocated TCM configfs fabric module */
@@ -564,13 +569,7 @@ 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;
-
-	/* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
-	tv_tpg = vs->vs_tpg;
-	if (unlikely(!tv_tpg)) {
-		pr_err("%s endpoint not set\n", __func__);
-		return;
-	}
+	u8 target;
 
 	mutex_lock(&vq->mutex);
 	vhost_disable_notify(&vs->dev, vq);
@@ -637,6 +636,35 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
 			break;
 		}
 
+		/* Extract the tpgt */
+		target = v_req.lun[1];
+
+		/* Target does not exit, fail the request */
+		if (unlikely(target >= vs->vs_num_target)) {
+			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;
+		}
+
+		tv_tpg = vs->vs_tpg[target];
+		if (unlikely(!tv_tpg)) {
+			/* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
+			pr_err("endpoint not set, target = %d\n", target);
+			vhost_discard_vq_desc(vq, 1);
+			break;
+		}
+
 		exp_data_len = 0;
 		for (i = 0; i < data_num; i++)
 			exp_data_len += vq->iov[data_first + i].iov_len;
@@ -771,14 +799,11 @@ 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)) {
+		if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
 			tv_tpg->tv_tpg_vhost_count++;
-			mutex_unlock(&tv_tpg->tv_tpg_mutex);
-			mutex_unlock(&tcm_vhost_mutex);
 
 			mutex_lock(&vs->dev.mutex);
-			if (vs->vs_tpg) {
+			if (vs->vs_tpg[tv_tpg->tport_tpgt - 1]) {
 				mutex_unlock(&vs->dev.mutex);
 				mutex_lock(&tv_tpg->tv_tpg_mutex);
 				tv_tpg->tv_tpg_vhost_count--;
@@ -786,15 +811,17 @@ static int vhost_scsi_set_endpoint(
 				return -EEXIST;
 			}
 
-			vs->vs_tpg = tv_tpg;
+			vs->vs_tpg[tv_tpg->tport_tpgt - 1] = tv_tpg;
 			smp_mb__after_atomic_inc();
+			if (!vs->vs_num_target++)
+				memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
+				       sizeof(vs->vs_vhost_wwpn));
 			mutex_unlock(&vs->dev.mutex);
-			return 0;
 		}
 		mutex_unlock(&tv_tpg->tv_tpg_mutex);
 	}
 	mutex_unlock(&tcm_vhost_mutex);
-	return -EINVAL;
+	return 0;
 }
 
 static int vhost_scsi_clear_endpoint(
@@ -803,7 +830,8 @@ 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. */
@@ -813,27 +841,32 @@ static int vhost_scsi_clear_endpoint(
 			goto err;
 		}
 	}
+	for (i = 0; i < vs->vs_num_target; i++) {
+		target = i;
 
-	if (!vs->vs_tpg) {
-		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)) {
-		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,
-			t->vhost_wwpn, t->vhost_tpgt);
-		ret = -EINVAL;
-		goto err;
+		tv_tpg = vs->vs_tpg[target];
+		if (!tv_tpg) {
+			ret = -ENODEV;
+			goto err;
+		}
+		tv_tport = tv_tpg->tport;
+		if (!tv_tport) {
+			ret = -ENODEV;
+			goto err;
+		}
+
+		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,
+				t->vhost_wwpn, t->vhost_tpgt);
+			ret = -EINVAL;
+			goto err;
+		}
+		tv_tpg->tv_tpg_vhost_count--;
+		vs->vs_tpg[target] = NULL;
 	}
-	tv_tpg->tv_tpg_vhost_count--;
-	vs->vs_tpg = NULL;
 	mutex_unlock(&vs->dev.mutex);
-
 	return 0;
 
 err:
@@ -868,16 +901,10 @@ 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);
-	}
-
+	memcpy(t.vhost_wwpn, s->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
+	vhost_scsi_clear_endpoint(s, &t);
 	vhost_dev_stop(&s->dev);
 	vhost_dev_cleanup(&s->dev, false);
 	kfree(s);
diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
index 47ee80b..519a550 100644
--- a/drivers/vhost/tcm_vhost.h
+++ b/drivers/vhost/tcm_vhost.h
@@ -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;
-- 
1.8.1

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux