mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 21:21:41 +00:00
[SCSI] virtio-scsi: hotplug support for virtio-scsi
This patch implements the hotplug support for virtio-scsi. When there is a device attached/detached, the virtio-scsi driver will be signaled via event virtual queue and it will add/remove the scsi device in question automatically. Signed-off-by: Sen Wang <senwang@linux.vnet.ibm.com> Signed-off-by: Cong Meng <mc@linux.vnet.ibm.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Cong Meng
James Bottomley
parent
2bd37f0fde
commit
365a715009
@ -25,6 +25,7 @@
|
||||
#include <scsi/scsi_cmnd.h>
|
||||
|
||||
#define VIRTIO_SCSI_MEMPOOL_SZ 64
|
||||
#define VIRTIO_SCSI_EVENT_LEN 8
|
||||
|
||||
/* Command queue element */
|
||||
struct virtio_scsi_cmd {
|
||||
@ -43,6 +44,12 @@ struct virtio_scsi_cmd {
|
||||
} resp;
|
||||
} ____cacheline_aligned_in_smp;
|
||||
|
||||
struct virtio_scsi_event_node {
|
||||
struct virtio_scsi *vscsi;
|
||||
struct virtio_scsi_event event;
|
||||
struct work_struct work;
|
||||
};
|
||||
|
||||
struct virtio_scsi_vq {
|
||||
/* Protects vq */
|
||||
spinlock_t vq_lock;
|
||||
@ -67,6 +74,9 @@ struct virtio_scsi {
|
||||
struct virtio_scsi_vq event_vq;
|
||||
struct virtio_scsi_vq req_vq;
|
||||
|
||||
/* Get some buffers ready for event vq */
|
||||
struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
|
||||
|
||||
struct virtio_scsi_target_state *tgt[];
|
||||
};
|
||||
|
||||
@ -202,6 +212,105 @@ static void virtscsi_ctrl_done(struct virtqueue *vq)
|
||||
spin_unlock_irqrestore(&vscsi->ctrl_vq.vq_lock, flags);
|
||||
};
|
||||
|
||||
static int virtscsi_kick_event(struct virtio_scsi *vscsi,
|
||||
struct virtio_scsi_event_node *event_node)
|
||||
{
|
||||
int ret;
|
||||
struct scatterlist sg;
|
||||
unsigned long flags;
|
||||
|
||||
sg_set_buf(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
|
||||
|
||||
spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
|
||||
|
||||
ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
|
||||
if (ret >= 0)
|
||||
virtqueue_kick(vscsi->event_vq.vq);
|
||||
|
||||
spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
|
||||
vscsi->event_list[i].vscsi = vscsi;
|
||||
virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
|
||||
cancel_work_sync(&vscsi->event_list[i].work);
|
||||
}
|
||||
|
||||
static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
|
||||
struct virtio_scsi_event *event)
|
||||
{
|
||||
struct scsi_device *sdev;
|
||||
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
|
||||
unsigned int target = event->lun[1];
|
||||
unsigned int lun = (event->lun[2] << 8) | event->lun[3];
|
||||
|
||||
switch (event->reason) {
|
||||
case VIRTIO_SCSI_EVT_RESET_RESCAN:
|
||||
scsi_add_device(shost, 0, target, lun);
|
||||
break;
|
||||
case VIRTIO_SCSI_EVT_RESET_REMOVED:
|
||||
sdev = scsi_device_lookup(shost, 0, target, lun);
|
||||
if (sdev) {
|
||||
scsi_remove_device(sdev);
|
||||
scsi_device_put(sdev);
|
||||
} else {
|
||||
pr_err("SCSI device %d 0 %d %d not found\n",
|
||||
shost->host_no, target, lun);
|
||||
}
|
||||
break;
|
||||
default:
|
||||
pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
|
||||
}
|
||||
}
|
||||
|
||||
static void virtscsi_handle_event(struct work_struct *work)
|
||||
{
|
||||
struct virtio_scsi_event_node *event_node =
|
||||
container_of(work, struct virtio_scsi_event_node, work);
|
||||
struct virtio_scsi *vscsi = event_node->vscsi;
|
||||
struct virtio_scsi_event *event = &event_node->event;
|
||||
|
||||
if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
|
||||
event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
|
||||
scsi_scan_host(virtio_scsi_host(vscsi->vdev));
|
||||
}
|
||||
|
||||
switch (event->event) {
|
||||
case VIRTIO_SCSI_T_NO_EVENT:
|
||||
break;
|
||||
case VIRTIO_SCSI_T_TRANSPORT_RESET:
|
||||
virtscsi_handle_transport_reset(vscsi, event);
|
||||
break;
|
||||
default:
|
||||
pr_err("Unsupport virtio scsi event %x\n", event->event);
|
||||
}
|
||||
virtscsi_kick_event(vscsi, event_node);
|
||||
}
|
||||
|
||||
static void virtscsi_complete_event(void *buf)
|
||||
{
|
||||
struct virtio_scsi_event_node *event_node = buf;
|
||||
|
||||
INIT_WORK(&event_node->work, virtscsi_handle_event);
|
||||
schedule_work(&event_node->work);
|
||||
}
|
||||
|
||||
static void virtscsi_event_done(struct virtqueue *vq)
|
||||
{
|
||||
struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
|
||||
@ -209,7 +318,7 @@ static void virtscsi_event_done(struct virtqueue *vq)
|
||||
unsigned long flags;
|
||||
|
||||
spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
|
||||
virtscsi_vq_done(vq, virtscsi_complete_free);
|
||||
virtscsi_vq_done(vq, virtscsi_complete_event);
|
||||
spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
|
||||
};
|
||||
|
||||
@ -510,6 +619,9 @@ static int virtscsi_init(struct virtio_device *vdev,
|
||||
virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
|
||||
virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
|
||||
|
||||
if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
|
||||
virtscsi_kick_event_all(vscsi);
|
||||
|
||||
/* We need to know how many segments before we allocate. */
|
||||
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
|
||||
|
||||
@ -580,6 +692,10 @@ virtscsi_init_failed:
|
||||
static void __devexit virtscsi_remove(struct virtio_device *vdev)
|
||||
{
|
||||
struct Scsi_Host *shost = virtio_scsi_host(vdev);
|
||||
struct virtio_scsi *vscsi = shost_priv(shost);
|
||||
|
||||
if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
|
||||
virtscsi_cancel_event_work(vscsi);
|
||||
|
||||
scsi_remove_host(shost);
|
||||
|
||||
@ -608,7 +724,13 @@ static struct virtio_device_id id_table[] = {
|
||||
{ 0 },
|
||||
};
|
||||
|
||||
static unsigned int features[] = {
|
||||
VIRTIO_SCSI_F_HOTPLUG
|
||||
};
|
||||
|
||||
static struct virtio_driver virtio_scsi_driver = {
|
||||
.feature_table = features,
|
||||
.feature_table_size = ARRAY_SIZE(features),
|
||||
.driver.name = KBUILD_MODNAME,
|
||||
.driver.owner = THIS_MODULE,
|
||||
.id_table = id_table,
|
||||
|
||||
@ -69,6 +69,10 @@ struct virtio_scsi_config {
|
||||
u32 max_lun;
|
||||
} __packed;
|
||||
|
||||
/* Feature Bits */
|
||||
#define VIRTIO_SCSI_F_INOUT 0
|
||||
#define VIRTIO_SCSI_F_HOTPLUG 1
|
||||
|
||||
/* Response codes */
|
||||
#define VIRTIO_SCSI_S_OK 0
|
||||
#define VIRTIO_SCSI_S_OVERRUN 1
|
||||
@ -105,6 +109,11 @@ struct virtio_scsi_config {
|
||||
#define VIRTIO_SCSI_T_TRANSPORT_RESET 1
|
||||
#define VIRTIO_SCSI_T_ASYNC_NOTIFY 2
|
||||
|
||||
/* Reasons of transport reset event */
|
||||
#define VIRTIO_SCSI_EVT_RESET_HARD 0
|
||||
#define VIRTIO_SCSI_EVT_RESET_RESCAN 1
|
||||
#define VIRTIO_SCSI_EVT_RESET_REMOVED 2
|
||||
|
||||
#define VIRTIO_SCSI_S_SIMPLE 0
|
||||
#define VIRTIO_SCSI_S_ORDERED 1
|
||||
#define VIRTIO_SCSI_S_HEAD 2
|
||||
|
||||
Loading…
Reference in New Issue
Block a user