[Qemu-devel] [PATCH] vhost-scsi: introduce an ioctl to get the minimum tpgt

[arei.gonglei]

From: Gonglei <address@hidden>

In order to support to assign a boot order for
vhost-scsi device, we should get the tpgt for
user level (such as Qemu). and at present, we
only support the minimum tpgt can boot.

Signed-off-by: Gonglei <address@hidden>
Signed-off-by: Bo Su <address@hidden>
---
 drivers/vhost/scsi.c       | 41 +++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/vhost.h |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index d695b16..12e79b9 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1522,6 +1522,38 @@ err_dev:
        return ret;
 }
 
+static int vhost_scsi_get_first_tpgt(
+               struct vhost_scsi *vs,
+               struct vhost_scsi_target *t)
+{
+       struct tcm_vhost_tpg *tv_tpg;
+       struct tcm_vhost_tport *tv_tport;
+       int tpgt = -1;
+
+       mutex_lock(&tcm_vhost_mutex);
+       mutex_lock(&vs->dev.mutex);
+
+       list_for_each_entry(tv_tpg, &tcm_vhost_list, tv_tpg_list) {
+               tv_tport = tv_tpg->tport;
+
+               if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
+                       if (tpgt < 0)
+                               tpgt = tv_tpg->tport_tpgt;
+                       else if (tpgt > tv_tpg->tport_tpgt)
+                               tpgt = tv_tpg->tport_tpgt;
+               }
+       }
+
+       mutex_unlock(&vs->dev.mutex);
+       mutex_unlock(&tcm_vhost_mutex);
+
+       if (tpgt < 0)
+               return -ENXIO;
+
+       t->vhost_tpgt = tpgt;
+       return 0;
+}
+
 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
 {
        struct vhost_virtqueue *vq;
@@ -1657,6 +1689,15 @@ vhost_scsi_ioctl(struct file *f,
                if (put_user(events_missed, eventsp))
                        return -EFAULT;
                return 0;
+       case VHOST_SCSI_GET_TPGT:
+               if (copy_from_user(&backend, argp, sizeof(backend)))
+                       return -EFAULT;
+               r = vhost_scsi_get_first_tpgt(vs, &backend);
+               if (r < 0)
+                       return r;
+               if (copy_to_user(argp, &backend, sizeof(backend)))
+                       return -EFAULT;
+               return 0;
        case VHOST_GET_FEATURES:
                features = VHOST_SCSI_FEATURES;
                if (copy_to_user(featurep, &features, sizeof features))
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index bb6a5b4..5d350f7 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -155,4 +155,6 @@ struct vhost_scsi_target {
 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
 
+#define VHOST_SCSI_GET_TPGT _IOW(VHOST_VIRTIO, 0x45, struct vhost_scsi_target)
+
 #endif
-- 
1.7.12.4