On Thu, 2013-01-31 at 17:28 +0800, Asias He wrote:
> Hello Nicholas,
>
> On 01/31/2013 03:33 PM, Asias He wrote:
> > In order to take advantages of Paolo's multi-queue virito-scsi, we need
> > multi-target support in tcm_vhost first. Otherwise all the requests go
> > to one queue and other queues are idle.
> >
> > This patch makes:
> >
> > 1. All the targets under the wwpn is seen and can be used by guest.
> > 2. No need to pass the tpgt number in struct vhost_scsi_target to
> > tcm_vhost.ko. Only wwpn is needed.
> > 3. We can always pass max_target = 255 to guest now, since we abort the
> > request who's target id does not exist.
> >
> > Signed-off-by: Asias He <asias@xxxxxxxxxx>
> > ---
> > drivers/vhost/tcm_vhost.c | 115 ++++++++++++++++++++++++++++------------------
> > drivers/vhost/tcm_vhost.h | 4 +-
> > 2 files changed, 74 insertions(+), 45 deletions(-)
> >
> > diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
> > index 218deb6..d50cb95 100644
> > --- a/drivers/vhost/tcm_vhost.c
> > +++ b/drivers/vhost/tcm_vhost.c
> > @@ -59,13 +59,18 @@ enum {
> > VHOST_SCSI_VQ_IO = 2,
> > };
> >
> > +#define VHOST_SCSI_MAX_TARGET 256
> > +
> > struct vhost_scsi {
> > - struct tcm_vhost_tpg *vs_tpg; /* Protected by vhost_scsi->dev.mutex */
> > + /* Protected by vhost_scsi->dev.mutex */
> > + struct tcm_vhost_tpg *vs_tpg[VHOST_SCSI_MAX_TARGET];
> > struct vhost_dev dev;
> > struct vhost_virtqueue vqs[3];
> >
> > struct vhost_work vs_completion_work; /* cmd completion work item */
> > struct llist_head vs_completion_list; /* cmd completion queue */
> > + char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
> > + int vs_num_target;
> > };
> >
> > /* Local pointer to allocated TCM configfs fabric module */
> > @@ -564,13 +569,7 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> > u32 exp_data_len, data_first, data_num, data_direction;
> > unsigned out, in, i;
> > int head, ret;
> > -
> > - /* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
> > - tv_tpg = vs->vs_tpg;
> > - if (unlikely(!tv_tpg)) {
> > - pr_err("%s endpoint not set\n", __func__);
> > - return;
> > - }
> > + u8 target;
> >
> > mutex_lock(&vq->mutex);
> > vhost_disable_notify(&vs->dev, vq);
> > @@ -637,6 +636,35 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> > break;
> > }
> >
> > + /* Extract the tpgt */
> > + target = v_req.lun[1];
> > +
> > + /* Target does not exit, fail the request */
> > + if (unlikely(target >= vs->vs_num_target)) {
> > + struct virtio_scsi_cmd_resp __user *resp;
> > + struct virtio_scsi_cmd_resp rsp;
> > +
> > + memset(&rsp, 0, sizeof(rsp));
> > + rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
> > + resp = vq->iov[out].iov_base;
> > + ret = copy_to_user(resp, &rsp, sizeof(rsp));
> > + if (!ret)
> > + vhost_add_used_and_signal(&vs->dev,
> > + &vs->vqs[2], head, 0);
> > + else
> > + pr_err("Faulted on virtio_scsi_cmd_resp\n");
> > +
> > + continue;
> > + }
> > +
> > + tv_tpg = vs->vs_tpg[target];
> > + if (unlikely(!tv_tpg)) {
> > + /* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
> > + pr_err("endpoint not set, target = %d\n", target);
> > + vhost_discard_vq_desc(vq, 1);
> > + break;
> > + }
> > +
> > exp_data_len = 0;
> > for (i = 0; i < data_num; i++)
> > exp_data_len += vq->iov[data_first + i].iov_len;
> > @@ -771,14 +799,11 @@ static int vhost_scsi_set_endpoint(
> > }
> > tv_tport = tv_tpg->tport;
> >
> > - if (!strcmp(tv_tport->tport_name, t->vhost_wwpn) &&
> > - (tv_tpg->tport_tpgt == t->vhost_tpgt)) {
> > + if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
> > tv_tpg->tv_tpg_vhost_count++;
> > - mutex_unlock(&tv_tpg->tv_tpg_mutex);
> > - mutex_unlock(&tcm_vhost_mutex);
> >
> > mutex_lock(&vs->dev.mutex);
> > - if (vs->vs_tpg) {
> > + if (vs->vs_tpg[tv_tpg->tport_tpgt - 1]) {
> > mutex_unlock(&vs->dev.mutex);
> > mutex_lock(&tv_tpg->tv_tpg_mutex);
> > tv_tpg->tv_tpg_vhost_count--;
> > @@ -786,15 +811,17 @@ static int vhost_scsi_set_endpoint(
> > return -EEXIST;
> > }
> >
> > - vs->vs_tpg = tv_tpg;
> > + vs->vs_tpg[tv_tpg->tport_tpgt - 1] = tv_tpg;
>
>
> tv_tpg->tport_tpgt starts from 0, right? I thought it starts from 1,
> because I always got it starts from 1 in targetcli.
>
> o- vhost
> o- naa.6001405bd4e8476d
> o- tpg1
> o- luns
> o- lun0
> o- tpg2
> o- luns
> o- lun0
> o- tpg3
> o- luns
> o- lun0
> o- tpg4
> o- luns
> o- lun0
>
So at least with iscsi-target, we start from tpgt=1 to avoid some legacy
initiators that have issues handling tgpt=0.
Given that rtslib/targetcli currently expect this with the "tpgs"
feature is enabled, starting from tpgt=1 with tcm_vhost probably makes
the most sense.
> If it is true. I will cook v2 of this patch.
>
> Also, the tv_tpg->tport_tpgt can be none-continuous. e.g.
>
> o- vhost
> o- naa.6001405bd4e8476d
> o- tpg1
> o- luns
> o- lun0
> o- tpg2
> o- luns
> o- lun0
> o- tpg4
> o- luns
> o- lun0
>
> I will handle this in v2.
>
Correct, tpgt values may be optionally non-contiguous up to unsigned
short.
--nab
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