From 1b7f390eb3bfc197c979c5478eadbc2a90f07667 Mon Sep 17 00:00:00 2001 From: Asias He Date: Wed, 6 Feb 2013 13:20:59 +0800 Subject: tcm_vhost: Multi-queue support This adds virtio-scsi multi-queue support to tcm_vhost. In order to use multi-queue, guest side multi-queue support is need. It can be found here: https://lkml.org/lkml/2012/12/18/166 Currently, only one thread is created by vhost core code for each vhost_scsi instance. Even if there are multi-queues, all the handling of guest kick (vhost_scsi_handle_kick) are processed in one thread. This is not optimal. Luckily, most of the work is offloaded to the tcm_vhost workqueue. 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 Signed-off-by: Asias He Signed-off-by: Nicholas Bellinger --- 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 81ecda54b923..9951297b2427 100644 --- a/drivers/vhost/tcm_vhost.c +++ b/drivers/vhost/tcm_vhost.c @@ -48,6 +48,7 @@ #include /* TODO vhost.h currently depends on this */ #include #include +#include #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 519a5504d347..1d2ae7a60e11 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() */ -- cgit v1.2.3