In commit 365a7150094 ([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.
Changes in v5:
- Switch to int from u64 to vs_events_nr
- Set s->vs_events_dropped flag in tcm_vhost_allocate_evt
- Do not nest dev mutex within vq mutex
- Use vs_events_lock to protect vs_events_dropped and vs_events_nr
- Rebase to target/master
Changes in v4:
- Drop tcm_vhost_check_endpoint in tcm_vhost_send_evt
- Add tcm_vhost_check_endpoint in vhost_scsi_evt_handle_kick
Changes in v3:
- Separate the bug fix to another thread
Changes in v2:
- Remove code duplication in tcm_vhost_{hotplug,hotunplug}
- Fix racing of vs_events_nr
- Add flush fix patch to this series
Signed-off-by: Asias He <as...@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
---
drivers/vhost/tcm_vhost.c | 206 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/vhost/tcm_vhost.h | 10 +++
2 files changed, 212 insertions(+), 4 deletions(-)
diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index 7069881..3351ed3 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -66,11 +66,13 @@ enum {
* TODO: debug and remove the workaround.
*/
enum {
- VHOST_SCSI_FEATURES = VHOST_FEATURES & (~VIRTIO_RING_F_EVENT_IDX)
+ VHOST_SCSI_FEATURES = (VHOST_FEATURES & (~VIRTIO_RING_F_EVENT_IDX)) |
+ (1ULL << VIRTIO_SCSI_F_HOTPLUG)
};
#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 +84,13 @@ 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 */
+
+ struct mutex vs_events_lock; /* protect vs_events_dropped,events_nr */
+ bool vs_events_dropped; /* any missed events */
+ int vs_events_nr; /* num of pending events */
};
/* Local pointer to allocated TCM configfs fabric module */
@@ -129,6 +138,17 @@ static bool tcm_vhost_check_endpoint(struct
vhost_virtqueue *vq)
return ret;
}
+static bool tcm_vhost_check_events_dropped(struct vhost_scsi *vs)
+{
+ bool ret;
+
+ mutex_lock(&vs->vs_events_lock);
+ ret = vs->vs_events_dropped;
+ mutex_unlock(&vs->vs_events_lock);
+
+ return ret;
+}
+
static int tcm_vhost_check_true(struct se_portal_group *se_tpg)
{
return 1;
@@ -379,6 +399,37 @@ 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)
+{
+ mutex_lock(&vs->vs_events_lock);
+ vs->vs_events_nr--;
+ kfree(evt);
+ mutex_unlock(&vs->vs_events_lock);
+}
+
+static struct tcm_vhost_evt *tcm_vhost_allocate_evt(struct vhost_scsi *vs,
+ u32 event, u32 reason)
+{
+ struct tcm_vhost_evt *evt;
+
+ mutex_lock(&vs->vs_events_lock);
+ if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
+ vs->vs_events_dropped = true;
+ mutex_unlock(&vs->vs_events_lock);
+ return NULL;
+ }
+
+ evt = kzalloc(sizeof(*evt), GFP_KERNEL);
+ if (evt) {
+ evt->event.event = event;
+ evt->event.reason = reason;
+ vs->vs_events_nr++;
+ }
+ mutex_unlock(&vs->vs_events_lock);
+
+ return evt;
+}
+
static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
{
struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
@@ -397,6 +448,74 @@ 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 virtio_scsi_event *event)
+{
+ struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT];
+ struct virtio_scsi_event __user *eventp;
+ unsigned out, in;
+ int head, ret;
+
+ if (!tcm_vhost_check_endpoint(vq))
+ return;
+
+ mutex_lock(&vs->vs_events_lock);
+ mutex_lock(&vq->mutex);
+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_dropped = true;
+ goto out;
+ }
+ if (head == vq->num) {
+ if (vhost_enable_notify(&vs->dev, vq))
+ goto again;
+ vs->vs_events_dropped = true;
+ goto out;
+ }
+
+ 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_dropped = true;
+ goto out;
+ }
+
+ if (vs->vs_events_dropped) {
+ event->event |= VIRTIO_SCSI_T_EVENTS_MISSED;
+ vs->vs_events_dropped = 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");
+out:
+ mutex_unlock(&vq->mutex);
+ mutex_unlock(&vs->vs_events_lock);
+}
+
+static void tcm_vhost_evt_work(struct vhost_work *work)
+{
+ struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
+ vs_event_work);
+ struct tcm_vhost_evt *evt;
+ struct llist_node *llnode;
+
+ 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->event);
+ tcm_vhost_free_evt(vs, evt);
+ }
+}
+
/* 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
@@ -804,9 +923,42 @@ static void vhost_scsi_ctl_handle_kick(struct vhost_work
*work)
pr_debug("%s: The handling func for control queue.\n", __func__);
}
+static int 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 -ENOMEM;
+
+ if (tpg && lun) {
+ /* TODO: share lun setup code with virtio-scsi.ko */
+ 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);
+
+ return 0;
+}
+
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);
+
+ if (!tcm_vhost_check_endpoint(vq))
+ return;
+
+ if (tcm_vhost_check_events_dropped(vs))
+ tcm_vhost_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
+
}
static void vhost_scsi_handle_kick(struct vhost_work *work)
@@ -888,6 +1040,7 @@ static int vhost_scsi_set_endpoint(
return -EEXIST;
}
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;
@@ -971,6 +1124,7 @@ 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);
@@ -1030,6 +1184,11 @@ 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_dropped = false;
+ mutex_init(&s->vs_events_lock);
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;
@@ -1160,6 +1319,42 @@ static char *tcm_vhost_dump_proto_id(struct
tcm_vhost_tport *tport)
return "Unknown";
}
+static int tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
+ struct se_lun *lun, bool plug)
+{
+
+ struct vhost_scsi *vs = tpg->vhost_scsi;
+ u32 reason;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ vs = tpg->vhost_scsi;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ if (!vs)
+ return -EOPNOTSUPP;
+
+ if (!tcm_vhost_check_feature(vs, VIRTIO_SCSI_F_HOTPLUG))
+ return -EOPNOTSUPP;
+
+ if (plug)
+ reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
+ else
+ reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
+
+ return tcm_vhost_send_evt(vs, tpg, lun,
+ VIRTIO_SCSI_T_TRANSPORT_RESET,
+ reason);
+}
+
+static int tcm_vhost_hotplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
+{
+ return tcm_vhost_do_plug(tpg, lun, true);
+}
+
+static int tcm_vhost_hotunplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
+{
+ return tcm_vhost_do_plug(tpg, lun, false);
+}
+
static int tcm_vhost_port_link(struct se_portal_group *se_tpg,
struct se_lun *lun)
{
@@ -1170,18 +1365,21 @@ static int tcm_vhost_port_link(struct se_portal_group
*se_tpg,
tv_tpg->tv_tpg_port_count++;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
+ tcm_vhost_hotplug(tv_tpg, lun);
+
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(&tv_tpg->tv_tpg_mutex);
tv_tpg->tv_tpg_port_count--;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
+
+ tcm_vhost_hotunplug(tv_tpg, lun);
}
static struct se_node_acl *tcm_vhost_make_nodeacl(
diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
index 1d2ae7a..94e9ee53 100644
--- a/drivers/vhost/tcm_vhost.h
+++ b/drivers/vhost/tcm_vhost.h
@@ -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 struct 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 {
+ /* virtio_scsi event */
+ struct virtio_scsi_event event;
+ /* virtio_scsi 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..
--
1.8.1.4
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
