diff options
| -rw-r--r-- | drivers/block/xen-blkfront.c | 160 |
1 files changed, 119 insertions, 41 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index a9058bbdaa6b..81c87e69cbe9 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -99,6 +99,10 @@ static unsigned int xen_blkif_max_segments = 32; module_param_named(max, xen_blkif_max_segments, int, S_IRUGO); MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)"); +static unsigned int xen_blkif_max_queues = 4; +module_param_named(max_queues, xen_blkif_max_queues, uint, S_IRUGO); +MODULE_PARM_DESC(max_queues, "Maximum number of hardware queues/rings used per virtual disk"); + /* * Maximum order of pages to be used for the shared ring between front and * backend, 4KB page granularity is used. @@ -118,6 +122,10 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the * characters are enough. Define to 20 to keep consist with backend. */ #define RINGREF_NAME_LEN (20) +/* + * queue-%u would take 7 + 10(UINT_MAX) = 17 characters. + */ +#define QUEUE_NAME_LEN (17) /* * Per-ring info. @@ -823,7 +831,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, memset(&info->tag_set, 0, sizeof(info->tag_set)); info->tag_set.ops = &blkfront_mq_ops; - info->tag_set.nr_hw_queues = 1; + info->tag_set.nr_hw_queues = info->nr_rings; info->tag_set.queue_depth = BLK_RING_SIZE(info); info->tag_set.numa_node = NUMA_NO_NODE; info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; @@ -1522,6 +1530,53 @@ fail: return err; } +/* + * Write out per-ring/queue nodes including ring-ref and event-channel, and each + * ring buffer may have multi pages depending on ->nr_ring_pages. + */ +static int write_per_ring_nodes(struct xenbus_transaction xbt, + struct blkfront_ring_info *rinfo, const char *dir) +{ + int err; + unsigned int i; + const char *message = NULL; + struct blkfront_info *info = rinfo->dev_info; + + if (info->nr_ring_pages == 1) { + err = xenbus_printf(xbt, dir, "ring-ref", "%u", rinfo->ring_ref[0]); + if (err) { + message = "writing ring-ref"; + goto abort_transaction; + } + } else { + for (i = 0; i < info->nr_ring_pages; i++) { + char ring_ref_name[RINGREF_NAME_LEN]; + + snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); + err = xenbus_printf(xbt, dir, ring_ref_name, + "%u", rinfo->ring_ref[i]); + if (err) { + message = "writing ring-ref"; + goto abort_transaction; + } + } + } + + err = xenbus_printf(xbt, dir, "event-channel", "%u", rinfo->evtchn); + if (err) { + message = "writing event-channel"; + goto abort_transaction; + } + + return 0; + +abort_transaction: + xenbus_transaction_end(xbt, 1); + if (message) + xenbus_dev_fatal(info->xbdev, err, "%s", message); + + return err; +} /* Common code used when first setting up, and when resuming. */ static int talk_to_blkback(struct xenbus_device *dev, @@ -1529,10 +1584,9 @@ static int talk_to_blkback(struct xenbus_device *dev, { const char *message = NULL; struct xenbus_transaction xbt; - int err, i; - unsigned int max_page_order = 0; + int err; + unsigned int i, max_page_order = 0; unsigned int ring_page_order = 0; - struct blkfront_ring_info *rinfo; err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, "max-ring-page-order", "%u", &max_page_order); @@ -1544,7 +1598,8 @@ static int talk_to_blkback(struct xenbus_device *dev, } for (i = 0; i < info->nr_rings; i++) { - rinfo = &info->rinfo[i]; + struct blkfront_ring_info *rinfo = &info->rinfo[i]; + /* Create shared ring, alloc event channel. */ err = setup_blkring(dev, rinfo); if (err) @@ -1558,44 +1613,49 @@ again: goto destroy_blkring; } - if (info->nr_rings == 1) { - rinfo = &info->rinfo[0]; - if (info->nr_ring_pages == 1) { - err = xenbus_printf(xbt, dev->nodename, - "ring-ref", "%u", rinfo->ring_ref[0]); - if (err) { - message = "writing ring-ref"; - goto abort_transaction; - } - } else { - err = xenbus_printf(xbt, dev->nodename, - "ring-page-order", "%u", ring_page_order); - if (err) { - message = "writing ring-page-order"; - goto abort_transaction; - } + if (info->nr_ring_pages > 1) { + err = xenbus_printf(xbt, dev->nodename, "ring-page-order", "%u", + ring_page_order); + if (err) { + message = "writing ring-page-order"; + goto abort_transaction; + } + } - for (i = 0; i < info->nr_ring_pages; i++) { - char ring_ref_name[RINGREF_NAME_LEN]; + /* We already got the number of queues/rings in _probe */ + if (info->nr_rings == 1) { + err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename); + if (err) + goto destroy_blkring; + } else { + char *path; + size_t pathsize; - snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); - err = xenbus_printf(xbt, dev->nodename, ring_ref_name, - "%u", rinfo->ring_ref[i]); - if (err) { - message = "writing ring-ref"; - goto abort_transaction; - } - } - } - err = xenbus_printf(xbt, dev->nodename, - "event-channel", "%u", rinfo->evtchn); + err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", "%u", + info->nr_rings); if (err) { - message = "writing event-channel"; + message = "writing multi-queue-num-queues"; goto abort_transaction; } - } else { - /* Not supported at this stage. */ - goto abort_transaction; + + pathsize = strlen(dev->nodename) + QUEUE_NAME_LEN; + path = kmalloc(pathsize, GFP_KERNEL); + if (!path) { + err = -ENOMEM; + message = "ENOMEM while writing ring references"; + goto abort_transaction; + } + + for (i = 0; i < info->nr_rings; i++) { + memset(path, 0, pathsize); + snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i); + err = write_per_ring_nodes(xbt, &info->rinfo[i], path); + if (err) { + kfree(path); + goto destroy_blkring; + } + } + kfree(path); } err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", XEN_IO_PROTO_ABI_NATIVE); @@ -1619,8 +1679,7 @@ again: for (i = 0; i < info->nr_rings; i++) { unsigned int j; - - rinfo = &info->rinfo[i]; + struct blkfront_ring_info *rinfo = &info->rinfo[i]; for (j = 0; j < BLK_RING_SIZE(info); j++) rinfo->shadow[j].req.u.rw.id = j + 1; @@ -1652,6 +1711,7 @@ static int blkfront_probe(struct xenbus_device *dev, int err, vdevice; unsigned int r_index; struct blkfront_info *info; + unsigned int backend_max_queues = 0; /* FIXME: Use dynamic device id if this is not set. */ err = xenbus_scanf(XBT_NIL, dev->nodename, @@ -1701,7 +1761,18 @@ static int blkfront_probe(struct xenbus_device *dev, return -ENOMEM; } - info->nr_rings = 1; + info->xbdev = dev; + /* Check if backend supports multiple queues. */ + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "multi-queue-max-queues", "%u", &backend_max_queues); + if (err < 0) + backend_max_queues = 1; + + info->nr_rings = min(backend_max_queues, xen_blkif_max_queues); + /* We need at least one ring. */ + if (!info->nr_rings) + info->nr_rings = 1; + info->rinfo = kzalloc(sizeof(struct blkfront_ring_info) * info->nr_rings, GFP_KERNEL); if (!info->rinfo) { xenbus_dev_fatal(dev, -ENOMEM, "allocating ring_info structure"); @@ -2390,6 +2461,7 @@ static struct xenbus_driver blkfront_driver = { static int __init xlblk_init(void) { int ret; + int nr_cpus = num_online_cpus(); if (!xen_domain()) return -ENODEV; @@ -2400,6 +2472,12 @@ static int __init xlblk_init(void) xen_blkif_max_ring_order = 0; } + if (xen_blkif_max_queues > nr_cpus) { + pr_info("Invalid max_queues (%d), will use default max: %d.\n", + xen_blkif_max_queues, nr_cpus); + xen_blkif_max_queues = nr_cpus; + } + if (!xen_has_pv_disk_devices()) return -ENODEV; |