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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-21 18:19:38 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-21 18:19:38 -0800 |
commit | 641203549a21ba6a701aecd05c3dfc969ec670cc (patch) | |
tree | 5e3d177c380ed811b5bf37e0bf9b8098416a9bc6 /include/xen/interface/io | |
parent | 404a47410c26a115123885977053e9a1a4460929 (diff) | |
parent | e93d12ae3be91d18b2a46deebb90a3f516db3d3c (diff) | |
download | op-kernel-dev-641203549a21ba6a701aecd05c3dfc969ec670cc.zip op-kernel-dev-641203549a21ba6a701aecd05c3dfc969ec670cc.tar.gz |
Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
"This is the block driver pull request for 4.5, with the exception of
NVMe, which is in a separate branch and will be posted after this one.
This pull request contains:
- A set of bcache stability fixes, which have been acked by Kent.
These have been used and tested for more than a year by the
community, so it's about time that they got in.
- A set of drbd updates from the drbd team (Andreas, Lars, Philipp)
and Markus Elfring, Oleg Drokin.
- A set of fixes for xen blkback/front from the usual suspects, (Bob,
Konrad) as well as community based fixes from Kiri, Julien, and
Peng.
- A 2038 time fix for sx8 from Shraddha, with a fix from me.
- A small mtip32xx cleanup from Zhu Yanjun.
- A null_blk division fix from Arnd"
* 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits)
null_blk: use sector_div instead of do_div
mtip32xx: restrict variables visible in current code module
xen/blkfront: Fix crash if backend doesn't follow the right states.
xen/blkback: Fix two memory leaks.
xen/blkback: make st_ statistics per ring
xen/blkfront: Handle non-indirect grant with 64KB pages
xen-blkfront: Introduce blkif_ring_get_request
xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()
xen/blkback: Free resources if connect_ring failed.
xen/blocks: Return -EXX instead of -1
xen/blkback: make pool of persistent grants and free pages per-queue
xen/blkback: get the number of hardware queues/rings from blkfront
xen/blkback: pseudo support for multi hardware queues/rings
xen/blkback: separate ring information out of struct xen_blkif
xen/blkfront: correct setting for xen_blkif_max_ring_order
xen/blkfront: make persistent grants pool per-queue
xen/blkfront: Remove duplicate setting of ->xbdev.
xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors.
xen/blkfront: negotiate number of queues/rings to be used with backend
xen/blkfront: split per device io_lock
...
Diffstat (limited to 'include/xen/interface/io')
-rw-r--r-- | include/xen/interface/io/blkif.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index c33e1c4..8b8cfad 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -28,6 +28,54 @@ typedef uint16_t blkif_vdev_t; typedef uint64_t blkif_sector_t; /* + * Multiple hardware queues/rings: + * If supported, the backend will write the key "multi-queue-max-queues" to + * the directory for that vbd, and set its value to the maximum supported + * number of queues. + * Frontends that are aware of this feature and wish to use it can write the + * key "multi-queue-num-queues" with the number they wish to use, which must be + * greater than zero, and no more than the value reported by the backend in + * "multi-queue-max-queues". + * + * For frontends requesting just one queue, the usual event-channel and + * ring-ref keys are written as before, simplifying the backend processing + * to avoid distinguishing between a frontend that doesn't understand the + * multi-queue feature, and one that does, but requested only one queue. + * + * Frontends requesting two or more queues must not write the toplevel + * event-channel and ring-ref keys, instead writing those keys under sub-keys + * having the name "queue-N" where N is the integer ID of the queue/ring for + * which those keys belong. Queues are indexed from zero. + * For example, a frontend with two queues must write the following set of + * queue-related keys: + * + * /local/domain/1/device/vbd/0/multi-queue-num-queues = "2" + * /local/domain/1/device/vbd/0/queue-0 = "" + * /local/domain/1/device/vbd/0/queue-0/ring-ref = "<ring-ref#0>" + * /local/domain/1/device/vbd/0/queue-0/event-channel = "<evtchn#0>" + * /local/domain/1/device/vbd/0/queue-1 = "" + * /local/domain/1/device/vbd/0/queue-1/ring-ref = "<ring-ref#1>" + * /local/domain/1/device/vbd/0/queue-1/event-channel = "<evtchn#1>" + * + * It is also possible to use multiple queues/rings together with + * feature multi-page ring buffer. + * For example, a frontend requests two queues/rings and the size of each ring + * buffer is two pages must write the following set of related keys: + * + * /local/domain/1/device/vbd/0/multi-queue-num-queues = "2" + * /local/domain/1/device/vbd/0/ring-page-order = "1" + * /local/domain/1/device/vbd/0/queue-0 = "" + * /local/domain/1/device/vbd/0/queue-0/ring-ref0 = "<ring-ref#0>" + * /local/domain/1/device/vbd/0/queue-0/ring-ref1 = "<ring-ref#1>" + * /local/domain/1/device/vbd/0/queue-0/event-channel = "<evtchn#0>" + * /local/domain/1/device/vbd/0/queue-1 = "" + * /local/domain/1/device/vbd/0/queue-1/ring-ref0 = "<ring-ref#2>" + * /local/domain/1/device/vbd/0/queue-1/ring-ref1 = "<ring-ref#3>" + * /local/domain/1/device/vbd/0/queue-1/event-channel = "<evtchn#1>" + * + */ + +/* * REQUEST CODES. */ #define BLKIF_OP_READ 0 |