[SCSI] virtio-scsi: split scatterlist per target
To improve performance for I/O to different targets, add a separate scatterlist for each of them. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Paolo Bonzini
James Bottomley
parent
bce750b163
commit
2bd37f0fde
1 changed files with 94 additions and 47 deletions
|
|
@ -50,18 +50,24 @@ struct virtio_scsi_vq {
|
|||
struct virtqueue *vq;
|
||||
};
|
||||
|
||||
/* Per-target queue state */
|
||||
struct virtio_scsi_target_state {
|
||||
/* Protects sg. Lock hierarchy is tgt_lock -> vq_lock. */
|
||||
spinlock_t tgt_lock;
|
||||
|
||||
/* For sglist construction when adding commands to the virtqueue. */
|
||||
struct scatterlist sg[];
|
||||
};
|
||||
|
||||
/* Driver instance state */
|
||||
struct virtio_scsi {
|
||||
/* Protects sg[]. The lock hierarchy is sg_lock -> vq_lock. */
|
||||
spinlock_t sg_lock;
|
||||
|
||||
struct virtio_device *vdev;
|
||||
|
||||
struct virtio_scsi_vq ctrl_vq;
|
||||
struct virtio_scsi_vq event_vq;
|
||||
struct virtio_scsi_vq req_vq;
|
||||
|
||||
/* For sglist construction when adding commands to the virtqueue. */
|
||||
struct scatterlist sg[];
|
||||
struct virtio_scsi_target_state *tgt[];
|
||||
};
|
||||
|
||||
static struct kmem_cache *virtscsi_cmd_cache;
|
||||
|
|
@ -230,25 +236,17 @@ static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
|
|||
* @req_size : size of the request buffer
|
||||
* @resp_size : size of the response buffer
|
||||
*
|
||||
* Called with vq_lock held.
|
||||
* Called with tgt_lock held.
|
||||
*/
|
||||
static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
|
||||
static void virtscsi_map_cmd(struct virtio_scsi_target_state *tgt,
|
||||
struct virtio_scsi_cmd *cmd,
|
||||
unsigned *out_num, unsigned *in_num,
|
||||
size_t req_size, size_t resp_size)
|
||||
{
|
||||
struct scsi_cmnd *sc = cmd->sc;
|
||||
struct scatterlist *sg = vscsi->sg;
|
||||
struct scatterlist *sg = tgt->sg;
|
||||
unsigned int idx = 0;
|
||||
|
||||
if (sc) {
|
||||
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
|
||||
BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
|
||||
|
||||
/* TODO: check feature bit and fail if unsupported? */
|
||||
BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
|
||||
}
|
||||
|
||||
/* Request header. */
|
||||
sg_set_buf(&sg[idx++], &cmd->req, req_size);
|
||||
|
||||
|
|
@ -268,7 +266,8 @@ static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
|
|||
*in_num = idx - *out_num;
|
||||
}
|
||||
|
||||
static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtio_scsi_vq *vq,
|
||||
static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
|
||||
struct virtio_scsi_vq *vq,
|
||||
struct virtio_scsi_cmd *cmd,
|
||||
size_t req_size, size_t resp_size, gfp_t gfp)
|
||||
{
|
||||
|
|
@ -276,12 +275,12 @@ static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtio_scsi_vq *v
|
|||
unsigned long flags;
|
||||
int ret;
|
||||
|
||||
spin_lock_irqsave(&vscsi->sg_lock, flags);
|
||||
virtscsi_map_cmd(vscsi, cmd, &out_num, &in_num, req_size, resp_size);
|
||||
spin_lock_irqsave(&tgt->tgt_lock, flags);
|
||||
virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
|
||||
|
||||
spin_lock(&vq->vq_lock);
|
||||
ret = virtqueue_add_buf(vq->vq, vscsi->sg, out_num, in_num, cmd, gfp);
|
||||
spin_unlock(&vscsi->sg_lock);
|
||||
ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
|
||||
spin_unlock(&tgt->tgt_lock);
|
||||
if (ret >= 0)
|
||||
ret = virtqueue_kick_prepare(vq->vq);
|
||||
|
||||
|
|
@ -295,9 +294,16 @@ static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtio_scsi_vq *v
|
|||
static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
|
||||
{
|
||||
struct virtio_scsi *vscsi = shost_priv(sh);
|
||||
struct virtio_scsi_target_state *tgt = vscsi->tgt[sc->device->id];
|
||||
struct virtio_scsi_cmd *cmd;
|
||||
int ret;
|
||||
|
||||
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
|
||||
BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
|
||||
|
||||
/* TODO: check feature bit and fail if unsupported? */
|
||||
BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
|
||||
|
||||
dev_dbg(&sc->device->sdev_gendev,
|
||||
"cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
|
||||
|
||||
|
|
@ -322,7 +328,7 @@ static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
|
|||
BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
|
||||
memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
|
||||
|
||||
if (virtscsi_kick_cmd(vscsi, &vscsi->req_vq, cmd,
|
||||
if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
|
||||
sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
|
||||
GFP_ATOMIC) >= 0)
|
||||
ret = 0;
|
||||
|
|
@ -334,10 +340,11 @@ static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
|
|||
static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
|
||||
{
|
||||
DECLARE_COMPLETION_ONSTACK(comp);
|
||||
struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
|
||||
int ret = FAILED;
|
||||
|
||||
cmd->comp = ∁
|
||||
if (virtscsi_kick_cmd(vscsi, &vscsi->ctrl_vq, cmd,
|
||||
if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
|
||||
sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
|
||||
GFP_NOIO) < 0)
|
||||
goto out;
|
||||
|
|
@ -437,11 +444,49 @@ static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
|
|||
virtscsi_vq->vq = vq;
|
||||
}
|
||||
|
||||
static struct virtio_scsi_target_state *virtscsi_alloc_tgt(
|
||||
struct virtio_device *vdev, int sg_elems)
|
||||
{
|
||||
struct virtio_scsi_target_state *tgt;
|
||||
gfp_t gfp_mask = GFP_KERNEL;
|
||||
|
||||
/* We need extra sg elements at head and tail. */
|
||||
tgt = kmalloc(sizeof(*tgt) + sizeof(tgt->sg[0]) * (sg_elems + 2),
|
||||
gfp_mask);
|
||||
|
||||
if (!tgt)
|
||||
return NULL;
|
||||
|
||||
spin_lock_init(&tgt->tgt_lock);
|
||||
sg_init_table(tgt->sg, sg_elems + 2);
|
||||
return tgt;
|
||||
}
|
||||
|
||||
static void virtscsi_remove_vqs(struct virtio_device *vdev)
|
||||
{
|
||||
struct Scsi_Host *sh = virtio_scsi_host(vdev);
|
||||
struct virtio_scsi *vscsi = shost_priv(sh);
|
||||
u32 i, num_targets;
|
||||
|
||||
/* Stop all the virtqueues. */
|
||||
vdev->config->reset(vdev);
|
||||
|
||||
num_targets = sh->max_id;
|
||||
for (i = 0; i < num_targets; i++) {
|
||||
kfree(vscsi->tgt[i]);
|
||||
vscsi->tgt[i] = NULL;
|
||||
}
|
||||
|
||||
vdev->config->del_vqs(vdev);
|
||||
}
|
||||
|
||||
static int virtscsi_init(struct virtio_device *vdev,
|
||||
struct virtio_scsi *vscsi)
|
||||
struct virtio_scsi *vscsi, int num_targets)
|
||||
{
|
||||
int err;
|
||||
struct virtqueue *vqs[3];
|
||||
u32 i, sg_elems;
|
||||
|
||||
vq_callback_t *callbacks[] = {
|
||||
virtscsi_ctrl_done,
|
||||
virtscsi_event_done,
|
||||
|
|
@ -464,7 +509,23 @@ static int virtscsi_init(struct virtio_device *vdev,
|
|||
|
||||
virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
|
||||
virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
|
||||
return 0;
|
||||
|
||||
/* We need to know how many segments before we allocate. */
|
||||
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
|
||||
|
||||
for (i = 0; i < num_targets; i++) {
|
||||
vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
|
||||
if (!vscsi->tgt[i]) {
|
||||
err = -ENOMEM;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
err = 0;
|
||||
|
||||
out:
|
||||
if (err)
|
||||
virtscsi_remove_vqs(vdev);
|
||||
return err;
|
||||
}
|
||||
|
||||
static int __devinit virtscsi_probe(struct virtio_device *vdev)
|
||||
|
|
@ -472,31 +533,25 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
|
|||
struct Scsi_Host *shost;
|
||||
struct virtio_scsi *vscsi;
|
||||
int err;
|
||||
u32 sg_elems;
|
||||
u32 sg_elems, num_targets;
|
||||
u32 cmd_per_lun;
|
||||
|
||||
/* We need to know how many segments before we allocate.
|
||||
* We need an extra sg elements at head and tail.
|
||||
*/
|
||||
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
|
||||
|
||||
/* Allocate memory and link the structs together. */
|
||||
num_targets = virtscsi_config_get(vdev, max_target) + 1;
|
||||
shost = scsi_host_alloc(&virtscsi_host_template,
|
||||
sizeof(*vscsi) + sizeof(vscsi->sg[0]) * (sg_elems + 2));
|
||||
sizeof(*vscsi)
|
||||
+ num_targets * sizeof(struct virtio_scsi_target_state));
|
||||
|
||||
if (!shost)
|
||||
return -ENOMEM;
|
||||
|
||||
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
|
||||
shost->sg_tablesize = sg_elems;
|
||||
vscsi = shost_priv(shost);
|
||||
vscsi->vdev = vdev;
|
||||
vdev->priv = shost;
|
||||
|
||||
/* Random initializations. */
|
||||
spin_lock_init(&vscsi->sg_lock);
|
||||
sg_init_table(vscsi->sg, sg_elems + 2);
|
||||
|
||||
err = virtscsi_init(vdev, vscsi);
|
||||
err = virtscsi_init(vdev, vscsi, num_targets);
|
||||
if (err)
|
||||
goto virtscsi_init_failed;
|
||||
|
||||
|
|
@ -504,7 +559,7 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
|
|||
shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
|
||||
shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
|
||||
shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
|
||||
shost->max_id = virtscsi_config_get(vdev, max_target) + 1;
|
||||
shost->max_id = num_targets;
|
||||
shost->max_channel = 0;
|
||||
shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
|
||||
err = scsi_add_host(shost, &vdev->dev);
|
||||
|
|
@ -522,14 +577,6 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
|
|||
return err;
|
||||
}
|
||||
|
||||
static void virtscsi_remove_vqs(struct virtio_device *vdev)
|
||||
{
|
||||
/* Stop all the virtqueues. */
|
||||
vdev->config->reset(vdev);
|
||||
|
||||
vdev->config->del_vqs(vdev);
|
||||
}
|
||||
|
||||
static void __devexit virtscsi_remove(struct virtio_device *vdev)
|
||||
{
|
||||
struct Scsi_Host *shost = virtio_scsi_host(vdev);
|
||||
|
|
@ -552,7 +599,7 @@ static int virtscsi_restore(struct virtio_device *vdev)
|
|||
struct Scsi_Host *sh = virtio_scsi_host(vdev);
|
||||
struct virtio_scsi *vscsi = shost_priv(sh);
|
||||
|
||||
return virtscsi_init(vdev, vscsi);
|
||||
return virtscsi_init(vdev, vscsi, sh->max_id);
|
||||
}
|
||||
#endif
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue