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
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.
And we need to fix another problem mentioned by Paolo.
Otherwise we can not use this to tell if a target exists or the endpoint
is not setup.
target = v_req.lun[1];
tv_tpg = vs->vs_tpg[target];
if (tv_tpg)
/* target exist */
else
/* target does not exist*/
""" from paolo
Another small bug I found is an ordering problem between
VHOST_SET_VRING_KICK and VHOST_SCSI_SET_ENDPOINT. Starting the vq
causes a "vhost_scsi_handle_vq endpoint not set" error in dmesg.
Because of this I added the first two patches, which let me do
VHOST_SCSI_SET_ENDPOINT before VHOST_SET_VRING_KICK but after setting
up the vring.
"""
> smp_mb__after_atomic_inc();
> + if (!vs->vs_num_target++)
> + memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
> + sizeof(vs->vs_vhost_wwpn));
> mutex_unlock(&vs->dev.mutex);
> - return 0;
> }
> mutex_unlock(&tv_tpg->tv_tpg_mutex);
> }
> mutex_unlock(&tcm_vhost_mutex);
> - return -EINVAL;
> + return 0;
> }
>
> static int vhost_scsi_clear_endpoint(
> @@ -803,7 +830,8 @@ static int vhost_scsi_clear_endpoint(
> {
> struct tcm_vhost_tport *tv_tport;
> struct tcm_vhost_tpg *tv_tpg;
> - int index, ret;
> + int index, ret, i;
> + u8 target;
>
> mutex_lock(&vs->dev.mutex);
> /* Verify that ring has been setup correctly. */
> @@ -813,27 +841,32 @@ static int vhost_scsi_clear_endpoint(
> goto err;
> }
> }
> + for (i = 0; i < vs->vs_num_target; i++) {
> + target = i;
>
> - if (!vs->vs_tpg) {
> - ret = -ENODEV;
> - goto err;
> - }
> - tv_tpg = vs->vs_tpg;
> - tv_tport = tv_tpg->tport;
> -
> - if (strcmp(tv_tport->tport_name, t->vhost_wwpn) ||
> - (tv_tpg->tport_tpgt != t->vhost_tpgt)) {
> - pr_warn("tv_tport->tport_name: %s, tv_tpg->tport_tpgt: %hu"
> - " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
> - tv_tport->tport_name, tv_tpg->tport_tpgt,
> - t->vhost_wwpn, t->vhost_tpgt);
> - ret = -EINVAL;
> - goto err;
> + tv_tpg = vs->vs_tpg[target];
> + if (!tv_tpg) {
> + ret = -ENODEV;
> + goto err;
> + }
> + tv_tport = tv_tpg->tport;
> + if (!tv_tport) {
> + ret = -ENODEV;
> + goto err;
> + }
> +
> + if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
> + pr_warn("tv_tport->tport_name: %s, tv_tpg->tport_tpgt: %hu"
> + " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
> + tv_tport->tport_name, tv_tpg->tport_tpgt,
> + t->vhost_wwpn, t->vhost_tpgt);
> + ret = -EINVAL;
> + goto err;
> + }
> + tv_tpg->tv_tpg_vhost_count--;
> + vs->vs_tpg[target] = NULL;
> }
> - tv_tpg->tv_tpg_vhost_count--;
> - vs->vs_tpg = NULL;
> mutex_unlock(&vs->dev.mutex);
> -
> return 0;
>
> err:
> @@ -868,16 +901,10 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
> static int vhost_scsi_release(struct inode *inode, struct file *f)
> {
> struct vhost_scsi *s = f->private_data;
> + struct vhost_scsi_target t;
>
> - if (s->vs_tpg && s->vs_tpg->tport) {
> - struct vhost_scsi_target backend;
> -
> - memcpy(backend.vhost_wwpn, s->vs_tpg->tport->tport_name,
> - sizeof(backend.vhost_wwpn));
> - backend.vhost_tpgt = s->vs_tpg->tport_tpgt;
> - vhost_scsi_clear_endpoint(s, &backend);
> - }
> -
> + memcpy(t.vhost_wwpn, s->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
> + vhost_scsi_clear_endpoint(s, &t);
> vhost_dev_stop(&s->dev);
> vhost_dev_cleanup(&s->dev, false);
> kfree(s);
> diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
> index 47ee80b..519a550 100644
> --- a/drivers/vhost/tcm_vhost.h
> +++ b/drivers/vhost/tcm_vhost.h
> @@ -93,9 +93,11 @@ struct tcm_vhost_tport {
> *
> * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
> * RFC-v2 vhost-scsi userspace. Add GET_ABI_VERSION ioctl usage
> + * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
> + * All the targets under vhost_wwpn can be seen and used by guset.
> */
>
> -#define VHOST_SCSI_ABI_VERSION 0
> +#define VHOST_SCSI_ABI_VERSION 1
>
> struct vhost_scsi_target {
> int abi_version;
>
--
Asias
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