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tcm_vhost: Add hotplug/hotunplug support 

In commit 365a715009 ([SCSI] virtio-scsi: hotplug support for
virtio-scsi), hotplug support is added to virtio-scsi.

This patch adds hotplug and hotunplug support to tcm_vhost.

You can create or delete a LUN in targetcli to hotplug or hotunplug a
LUN in guest.

Signed-off-by: Asias He <asias@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Asias He 2013-04-25 15:35:21 +08:00 committed by Nicholas Bellinger
parent f2b7daf5b1
commit a6c9af8736
2 changed files with 218 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

210
drivers/vhost/tcm_vhost.c
View File

@ -71,6 +71,7 @@ enum {
#define VHOST_SCSI_MAX_TARGET 256
#define VHOST_SCSI_MAX_VQ 128
#define VHOST_SCSI_MAX_EVENT 128
struct vhost_scsi {
/* Protected by vhost_scsi->dev.mutex */
@ -82,6 +83,12 @@ struct vhost_scsi {
struct vhost_work vs_completion_work; /* cmd completion work item */
struct llist_head vs_completion_list; /* cmd completion queue */
struct vhost_work vs_event_work; /* evt injection work item */
struct llist_head vs_event_list; /* evt injection queue */
bool vs_events_missed; /* any missed events, protected by vq->mutex */
int vs_events_nr; /* num of pending events, protected by vq->mutex */
};
/* Local pointer to allocated TCM configfs fabric module */
@ -349,6 +356,37 @@ static int tcm_vhost_queue_tm_rsp(struct se_cmd *se_cmd)
return 0;
}
static void tcm_vhost_free_evt(struct vhost_scsi *vs, struct tcm_vhost_evt *evt)
{
vs->vs_events_nr--;
kfree(evt);
}
static struct tcm_vhost_evt *tcm_vhost_allocate_evt(struct vhost_scsi *vs,
u32 event, u32 reason)
{
struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
struct tcm_vhost_evt *evt;
if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
vs->vs_events_missed = true;
return NULL;
}
evt = kzalloc(sizeof(*evt), GFP_KERNEL);
if (!evt) {
vq_err(vq, "Failed to allocate tcm_vhost_evt\n");
vs->vs_events_missed = true;
return NULL;
}
evt->event.event = event;
evt->event.reason = reason;
vs->vs_events_nr++;
return evt;
}
static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
{
struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
@ -367,6 +405,75 @@ static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
kfree(tv_cmd);
}
static void tcm_vhost_do_evt_work(struct vhost_scsi *vs,
struct tcm_vhost_evt *evt)
{
struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
struct virtio_scsi_event *event = &evt->event;
struct virtio_scsi_event __user *eventp;
unsigned out, in;
int head, ret;
if (!vq->private_data) {
vs->vs_events_missed = true;
return;
}
again:
vhost_disable_notify(&vs->dev, vq);
head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
ARRAY_SIZE(vq->iov), &out, &in,
NULL, NULL);
if (head < 0) {
vs->vs_events_missed = true;
return;
}
if (head == vq->num) {
if (vhost_enable_notify(&vs->dev, vq))
goto again;
vs->vs_events_missed = true;
return;
}
if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
vq->iov[out].iov_len);
vs->vs_events_missed = true;
return;
}
if (vs->vs_events_missed) {
event->event |= VIRTIO_SCSI_T_EVENTS_MISSED;
vs->vs_events_missed = false;
}
eventp = vq->iov[out].iov_base;
ret = __copy_to_user(eventp, event, sizeof(*event));
if (!ret)
vhost_add_used_and_signal(&vs->dev, vq, head, 0);
else
vq_err(vq, "Faulted on tcm_vhost_send_event\n");
}
static void tcm_vhost_evt_work(struct vhost_work *work)
{
struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
vs_event_work);
struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
struct tcm_vhost_evt *evt;
struct llist_node *llnode;
mutex_lock(&vq->mutex);
llnode = llist_del_all(&vs->vs_event_list);
while (llnode) {
evt = llist_entry(llnode, struct tcm_vhost_evt, list);
llnode = llist_next(llnode);
tcm_vhost_do_evt_work(vs, evt);
tcm_vhost_free_evt(vs, evt);
}
mutex_unlock(&vq->mutex);
}
/* Fill in status and signal that we are done processing this command
*
* This is scheduled in the vhost work queue so we are called with the owner
@ -777,9 +884,46 @@ static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
pr_debug("%s: The handling func for control queue.\n", __func__);
}
static void tcm_vhost_send_evt(struct vhost_scsi *vs, struct tcm_vhost_tpg *tpg,
struct se_lun *lun, u32 event, u32 reason)
{
struct tcm_vhost_evt *evt;
evt = tcm_vhost_allocate_evt(vs, event, reason);
if (!evt)
return;
if (tpg && lun) {
/* TODO: share lun setup code with virtio-scsi.ko */
/*
* Note: evt->event is zeroed when we allocate it and
* lun[4-7] need to be zero according to virtio-scsi spec.
*/
evt->event.lun[0] = 0x01;
evt->event.lun[1] = tpg->tport_tpgt & 0xFF;
if (lun->unpacked_lun >= 256)
evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
evt->event.lun[3] = lun->unpacked_lun & 0xFF;
}
llist_add(&evt->list, &vs->vs_event_list);
vhost_work_queue(&vs->dev, &vs->vs_event_work);
}
static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
{
pr_debug("%s: The handling func for event queue.\n", __func__);
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
poll.work);
struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
mutex_lock(&vq->mutex);
if (!vq->private_data)
goto out;
if (vs->vs_events_missed)
tcm_vhost_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
out:
mutex_unlock(&vq->mutex);
}
static void vhost_scsi_handle_kick(struct vhost_work *work)
@ -803,6 +947,7 @@ static void vhost_scsi_flush(struct vhost_scsi *vs)
for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
vhost_scsi_flush_vq(vs, i);
vhost_work_flush(&vs->dev, &vs->vs_completion_work);
vhost_work_flush(&vs->dev, &vs->vs_event_work);
}
/*
@ -864,6 +1009,7 @@ static int vhost_scsi_set_endpoint(
goto out;
}
tv_tpg->tv_tpg_vhost_count++;
tv_tpg->vhost_scsi = vs;
vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
smp_mb__after_atomic_inc();
match = true;
@ -949,6 +1095,7 @@ static int vhost_scsi_clear_endpoint(
goto err_tpg;
}
tv_tpg->tv_tpg_vhost_count--;
tv_tpg->vhost_scsi = NULL;
vs->vs_tpg[target] = NULL;
match = true;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
@ -969,6 +1116,7 @@ static int vhost_scsi_clear_endpoint(
vhost_scsi_flush(vs);
kfree(vs->vs_tpg);
vs->vs_tpg = NULL;
WARN_ON(vs->vs_events_nr);
mutex_unlock(&vs->dev.mutex);
mutex_unlock(&tcm_vhost_mutex);
return 0;
@ -1009,6 +1157,10 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
return -ENOMEM;
vhost_work_init(&s->vs_completion_work, vhost_scsi_complete_cmd_work);
vhost_work_init(&s->vs_event_work, tcm_vhost_evt_work);
s->vs_events_nr = 0;
s->vs_events_missed = false;
s->vqs[VHOST_SCSI_VQ_CTL].handle_kick = vhost_scsi_ctl_handle_kick;
s->vqs[VHOST_SCSI_VQ_EVT].handle_kick = vhost_scsi_evt_handle_kick;
@ -1035,6 +1187,8 @@ static int vhost_scsi_release(struct inode *inode, struct file *f)
vhost_scsi_clear_endpoint(s, &t);
vhost_dev_stop(&s->dev);
vhost_dev_cleanup(&s->dev, false);
/* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
vhost_scsi_flush(s);
kfree(s);
return 0;
}
@ -1139,28 +1293,80 @@ static char *tcm_vhost_dump_proto_id(struct tcm_vhost_tport *tport)
return "Unknown";
}
static void tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
struct se_lun *lun, bool plug)
{
struct vhost_scsi *vs = tpg->vhost_scsi;
struct vhost_virtqueue *vq;
u32 reason;
if (!vs)
return;
mutex_lock(&vs->dev.mutex);
if (!vhost_has_feature(&vs->dev, VIRTIO_SCSI_F_HOTPLUG)) {
mutex_unlock(&vs->dev.mutex);
return;
}
if (plug)
reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
else
reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
mutex_lock(&vq->mutex);
tcm_vhost_send_evt(vs, tpg, lun,
VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
mutex_unlock(&vq->mutex);
mutex_unlock(&vs->dev.mutex);
}
static void tcm_vhost_hotplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
{
tcm_vhost_do_plug(tpg, lun, true);
}
static void tcm_vhost_hotunplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
{
tcm_vhost_do_plug(tpg, lun, false);
}
static int tcm_vhost_port_link(struct se_portal_group *se_tpg,
struct se_lun *lun)
{
struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
struct tcm_vhost_tpg, se_tpg);
mutex_lock(&tcm_vhost_mutex);
mutex_lock(&tv_tpg->tv_tpg_mutex);
tv_tpg->tv_tpg_port_count++;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
tcm_vhost_hotplug(tv_tpg, lun);
mutex_unlock(&tcm_vhost_mutex);
return 0;
}
static void tcm_vhost_port_unlink(struct se_portal_group *se_tpg,
struct se_lun *se_lun)
struct se_lun *lun)
{
struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
struct tcm_vhost_tpg, se_tpg);
mutex_lock(&tcm_vhost_mutex);
mutex_lock(&tv_tpg->tv_tpg_mutex);
tv_tpg->tv_tpg_port_count--;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
tcm_vhost_hotunplug(tv_tpg, lun);
mutex_unlock(&tcm_vhost_mutex);
}
static struct se_node_acl *tcm_vhost_make_nodeacl(

10
drivers/vhost/tcm_vhost.h
View File

@ -53,6 +53,7 @@ struct tcm_vhost_nacl {
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;
@ -70,6 +71,8 @@ struct tcm_vhost_tpg {
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 {
@ -83,6 +86,13 @@ struct tcm_vhost_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..