On Wed, 2013-02-06 at 13:20 +0800, Asias He wrote:
> This adds virtio-scsi multi-queue support to tcm_vhost.
>
> Guest side virtio-scsi multi-queue support can be found here:
>
> https://lkml.org/lkml/2012/12/18/166
>
> Some initial perf numbers:
> 1 queue, 4 targets, 1 lun per target
> 4K request size, 50% randread + 50% randwrite: 127K/127k IOPS
>
> 4 queues, 4 targets, 1 lun per target
> 4K request size, 50% randread + 50% randwrite: 181K/181k IOPS
>
Nice single LUN small block random I/O improvement here with 4x vqueues.
Curious to see how virtio-scsi small block performance looks with
SCSI-core to multi-LUN tcm_vhost endpoints as well.. 8-)
Btw, this does not apply atop current target-pending.git/for-next with
your other pending vhost patch series, and AFAICT this patch is supposed
to apply on top of your last PATCH-v3, no..?
--nab
> Signed-off-by: Asias He <as...@redhat.com>
> ---
> drivers/vhost/tcm_vhost.c | 46 +++++++++++++++++++++++++++++-----------------
> drivers/vhost/tcm_vhost.h | 2 ++
> 2 files changed, 31 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
> index 81ecda5..9951297 100644
> --- a/drivers/vhost/tcm_vhost.c
> +++ b/drivers/vhost/tcm_vhost.c
> @@ -48,6 +48,7 @@
> #include <linux/virtio_net.h> /* TODO vhost.h currently depends on this */
> #include <linux/virtio_scsi.h>
> #include <linux/llist.h>
> +#include <linux/bitmap.h>
>
> #include "vhost.c"
> #include "vhost.h"
> @@ -59,7 +60,8 @@ enum {
> VHOST_SCSI_VQ_IO = 2,
> };
>
> -#define VHOST_SCSI_MAX_TARGET 256
> +#define VHOST_SCSI_MAX_TARGET 256
> +#define VHOST_SCSI_MAX_VQ 128
>
> struct vhost_scsi {
> /* Protected by vhost_scsi->dev.mutex */
> @@ -68,7 +70,7 @@ struct vhost_scsi {
> bool vs_endpoint;
>
> struct vhost_dev dev;
> - struct vhost_virtqueue vqs[3];
> + struct vhost_virtqueue vqs[VHOST_SCSI_MAX_VQ];
>
> struct vhost_work vs_completion_work; /* cmd completion work item */
> struct llist_head vs_completion_list; /* cmd completion queue */
> @@ -366,12 +368,14 @@ static void vhost_scsi_complete_cmd_work(struct
> vhost_work *work)
> {
> struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
> vs_completion_work);
> + DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
> struct virtio_scsi_cmd_resp v_rsp;
> struct tcm_vhost_cmd *tv_cmd;
> struct llist_node *llnode;
> struct se_cmd *se_cmd;
> - int ret;
> + int ret, vq;
>
> + bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
> llnode = llist_del_all(&vs->vs_completion_list);
> while (llnode) {
> tv_cmd = llist_entry(llnode, struct tcm_vhost_cmd,
> @@ -390,15 +394,20 @@ static void vhost_scsi_complete_cmd_work(struct
> vhost_work *work)
> memcpy(v_rsp.sense, tv_cmd->tvc_sense_buf,
> v_rsp.sense_len);
> ret = copy_to_user(tv_cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
> - if (likely(ret == 0))
> - vhost_add_used(&vs->vqs[2], tv_cmd->tvc_vq_desc, 0);
> - else
> + if (likely(ret == 0)) {
> + vhost_add_used(tv_cmd->tvc_vq, tv_cmd->tvc_vq_desc, 0);
> + vq = tv_cmd->tvc_vq - vs->vqs;
> + __set_bit(vq, signal);
> + } else
> pr_err("Faulted on virtio_scsi_cmd_resp\n");
>
> vhost_scsi_free_cmd(tv_cmd);
> }
>
> - vhost_signal(&vs->dev, &vs->vqs[2]);
> + vq = -1;
> + while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
> + < VHOST_SCSI_MAX_VQ)
> + vhost_signal(&vs->dev, &vs->vqs[vq]);
> }
>
> static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd(
> @@ -561,9 +570,9 @@ static void tcm_vhost_submission_work(struct work_struct
> *work)
> }
> }
>
> -static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> +static void vhost_scsi_handle_vq(struct vhost_scsi *vs,
> + struct vhost_virtqueue *vq)
> {
> - struct vhost_virtqueue *vq = &vs->vqs[2];
> struct virtio_scsi_cmd_req v_req;
> struct tcm_vhost_tpg *tv_tpg;
> struct tcm_vhost_cmd *tv_cmd;
> @@ -656,7 +665,7 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> ret = __copy_to_user(resp, &rsp, sizeof(rsp));
> if (!ret)
> vhost_add_used_and_signal(&vs->dev,
> - &vs->vqs[2], head, 0);
> + vq, head, 0);
> else
> pr_err("Faulted on virtio_scsi_cmd_resp\n");
>
> @@ -678,6 +687,7 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs)
> ": %d\n", tv_cmd, exp_data_len, data_direction);
>
> tv_cmd->tvc_vhost = vs;
> + tv_cmd->tvc_vq = vq;
>
> if (unlikely(vq->iov[out].iov_len !=
> sizeof(struct virtio_scsi_cmd_resp))) {
> @@ -758,7 +768,7 @@ static void vhost_scsi_handle_kick(struct vhost_work
> *work)
> poll.work);
> struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
>
> - vhost_scsi_handle_vq(vs);
> + vhost_scsi_handle_vq(vs, vq);
> }
>
> /*
> @@ -879,7 +889,7 @@ err:
> static int vhost_scsi_open(struct inode *inode, struct file *f)
> {
> struct vhost_scsi *s;
> - int r;
> + int r, i;
>
> s = kzalloc(sizeof(*s), GFP_KERNEL);
> if (!s)
> @@ -889,8 +899,9 @@ static int vhost_scsi_open(struct inode *inode, struct
> file *f)
>
> s->vqs[VHOST_SCSI_VQ_CTL].handle_kick = vhost_scsi_ctl_handle_kick;
> s->vqs[VHOST_SCSI_VQ_EVT].handle_kick = vhost_scsi_evt_handle_kick;
> - s->vqs[VHOST_SCSI_VQ_IO].handle_kick = vhost_scsi_handle_kick;
> - r = vhost_dev_init(&s->dev, s->vqs, 3);
> + for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++)
> + s->vqs[i].handle_kick = vhost_scsi_handle_kick;
> + r = vhost_dev_init(&s->dev, s->vqs, VHOST_SCSI_MAX_VQ);
> if (r < 0) {
> kfree(s);
> return r;
> @@ -922,9 +933,10 @@ static void vhost_scsi_flush_vq(struct vhost_scsi *vs,
> int index)
>
> static void vhost_scsi_flush(struct vhost_scsi *vs)
> {
> - vhost_scsi_flush_vq(vs, VHOST_SCSI_VQ_CTL);
> - vhost_scsi_flush_vq(vs, VHOST_SCSI_VQ_EVT);
> - vhost_scsi_flush_vq(vs, VHOST_SCSI_VQ_IO);
> + int i;
> +
> + for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
> + vhost_scsi_flush_vq(vs, i);
> }
>
> static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
> diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
> index 519a550..1d2ae7a 100644
> --- a/drivers/vhost/tcm_vhost.h
> +++ b/drivers/vhost/tcm_vhost.h
> @@ -23,6 +23,8 @@ struct tcm_vhost_cmd {
> struct virtio_scsi_cmd_resp __user *tvc_resp;
> /* Pointer to vhost_scsi for our device */
> struct vhost_scsi *tvc_vhost;
> + /* Pointer to vhost_virtqueue for the cmd */
> + struct vhost_virtqueue *tvc_vq;
> /* Pointer to vhost nexus memory */
> struct tcm_vhost_nexus *tvc_nexus;
> /* The TCM I/O descriptor that is accessed via container_of() */
--
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