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

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
......@@ -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);
......
......@@ -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;
......
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