Hi Asias,
On Fri, 2013-02-01 at 16:16 +0800, 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.
>
> Changes in v2:
> - Handle non-contiguous tpgt
>
> Signed-off-by: Asias He <as...@redhat.com>
> ---
So this patch is looks pretty good. Just a few points below..
> drivers/vhost/tcm_vhost.c | 117
> ++++++++++++++++++++++++++++++----------------
> drivers/vhost/tcm_vhost.h | 4 +-
> 2 files changed, 79 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
> index 218deb6..f1481f0 100644
> --- a/drivers/vhost/tcm_vhost.c
> +++ b/drivers/vhost/tcm_vhost.c
> @@ -59,8 +59,14 @@ 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];
> + char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
> + bool vs_endpoint;
> +
> struct vhost_dev dev;
> struct vhost_virtqueue vqs[3];
>
> @@ -564,13 +570,11 @@ 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;
> + u8 target;
>
> /* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
> - tv_tpg = vs->vs_tpg;
> - if (unlikely(!tv_tpg)) {
> - pr_err("%s endpoint not set\n", __func__);
> + if (unlikely(!vs->vs_endpoint))
> return;
> - }
>
> mutex_lock(&vq->mutex);
> vhost_disable_notify(&vs->dev, vq);
> @@ -637,6 +641,28 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> break;
> }
>
> + /* Extract the tpgt */
> + target = v_req.lun[1];
> + tv_tpg = vs->vs_tpg[target];
> +
> + /* Target does not exist, fail the request */
> + if (unlikely(!tv_tpg)) {
> + 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;
> + }
> +
> exp_data_len = 0;
> for (i = 0; i < data_num; i++)
> exp_data_len += vq->iov[data_first + i].iov_len;
> @@ -745,6 +771,7 @@ static int vhost_scsi_set_endpoint(
> {
> struct tcm_vhost_tport *tv_tport;
> struct tcm_vhost_tpg *tv_tpg;
> + bool match = false;
> int index;
>
> mutex_lock(&vs->dev.mutex);
> @@ -771,14 +798,11 @@ 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]) {
> mutex_unlock(&vs->dev.mutex);
> mutex_lock(&tv_tpg->tv_tpg_mutex);
> tv_tpg->tv_tpg_vhost_count--;
> @@ -786,15 +810,24 @@ static int vhost_scsi_set_endpoint(
> return -EEXIST;
> }
>
> - vs->vs_tpg = tv_tpg;
> + vs->vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
> smp_mb__after_atomic_inc();
> + match = true;
> mutex_unlock(&vs->dev.mutex);
> - return 0;
> }
> mutex_unlock(&tv_tpg->tv_tpg_mutex);
> }
> mutex_unlock(&tcm_vhost_mutex);
> - return -EINVAL;
> +
> + mutex_lock(&vs->dev.mutex);
> + if (match) {
> + memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
> + sizeof(vs->vs_vhost_wwpn));
> + vs->vs_endpoint = true;
> + }
> + mutex_unlock(&vs->dev.mutex);
> +
This looks racy to me.. Why not just set these while holding
vs->dev.mutex above, instead of releasing + re-aquire..?
> + return 0;
> }
>
> static int vhost_scsi_clear_endpoint(
> @@ -803,7 +836,8 @@ 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 +847,32 @@ static int vhost_scsi_clear_endpoint(
> goto err;
> }
> }
> + for (i = 0; i < VHOST_SCSI_MAX_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)
> + continue;
> +
> + 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;
> + vs->vs_endpoint = false;
> }
> - tv_tpg->tv_tpg_vhost_count--;
> - vs->vs_tpg = NULL;
> mutex_unlock(&vs->dev.mutex);
> -
> return 0;
>
> err:
> @@ -868,16 +907,12 @@ 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);
> - }
> -
> + mutex_lock(&s->dev.mutex);
> + memcpy(t.vhost_wwpn, s->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
> + mutex_unlock(&s->dev.mutex);
> + vhost_scsi_clear_endpoint(s, &t);
I think vhost_scsi_release() logic still needs a check here to prevent
vhost_scsi_clear_endpoint() from being called when no endpoint has been
configured, no..?
> 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
>
So Paolo's preference was to not bump the ABI rev for this change. I
don't really have a preference either way, so I'll defer to his and
MST's judgment here.
--nab
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