Il 20/06/2012 08:55, Cong Meng ha scritto: > 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: Cong Meng <mc@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Sen Wang <senwang@xxxxxxxxxxxxxxxxxx> Looks good (with one nit below), but please rebase over the four patches at http://permalink.gmane.org/gmane.linux.kernel/1312496 > --- > drivers/scsi/virtio_scsi.c | 109 ++++++++++++++++++++++++++++++++++++++++++- > include/linux/virtio_scsi.h | 9 ++++ > 2 files changed, 116 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c > index 1b38431..6dad625 100644 > --- a/drivers/scsi/virtio_scsi.c > +++ b/drivers/scsi/virtio_scsi.c > @@ -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 { > @@ -43,9 +44,15 @@ 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; > +}; > + > /* Driver instance state */ > struct virtio_scsi { > - /* Protects ctrl_vq, req_vq and sg[] */ > + /* Protects ctrl_vq, event_vq, req_vq and sg[] */ > spinlock_t vq_lock; > > struct virtio_device *vdev; > @@ -53,6 +60,9 @@ struct virtio_scsi { > struct virtqueue *event_vq; > struct virtqueue *req_vq; > > + /* Get some buffers reday for event vq */ > + struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; > + > /* For sglist construction when adding commands to the virtqueue. */ > struct scatterlist sg[]; > }; > @@ -184,9 +194,93 @@ static void virtscsi_ctrl_done(struct virtqueue *vq) > virtscsi_vq_done(vq, virtscsi_complete_free); > }; > > +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->vq_lock, flags); > + > + ret = virtqueue_add_buf(vscsi->event_vq, &sg, 0, 1, event_node, GFP_ATOMIC); > + if (ret >= 0) > + virtqueue_kick(vscsi->event_vq); > + > + spin_unlock_irqrestore(&vscsi->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_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; > + > + switch (event->event) { > + case VIRTIO_SCSI_T_TRANSPORT_RESET: > + virtscsi_handle_transport_reset(vscsi, event); > + break; Please handle VIRTIO_SCSI_T_NO_EVENT too here, and mask out VIRTIO_SCSI_T_EVENTS_MISSED even if you do not handle it by triggering a full rescan. Paolo > + 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) > { > - virtscsi_vq_done(vq, virtscsi_complete_free); > + virtscsi_vq_done(vq, virtscsi_complete_event); > }; > > static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx, > @@ -435,6 +529,11 @@ 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); > + } > + > return 0; > } > > @@ -532,7 +631,13 @@ 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, > diff --git a/include/linux/virtio_scsi.h b/include/linux/virtio_scsi.h > index 8ddeafd..dc8d305 100644 > --- a/include/linux/virtio_scsi.h > +++ b/include/linux/virtio_scsi.h > @@ -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 > Thanks, Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
