diff options
Diffstat (limited to 'drivers/block/xen-blkback')
| -rw-r--r-- | drivers/block/xen-blkback/blkback.c | 134 | ||||
| -rw-r--r-- | drivers/block/xen-blkback/common.h | 98 | ||||
| -rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 7 |
3 files changed, 198 insertions, 41 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 356722f65f88..1ebc0aa0f0e4 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -59,7 +59,7 @@ * IO workloads. */ -static int xen_blkif_max_buffer_pages = 704; +static int xen_blkif_max_buffer_pages = 1024; module_param_named(max_buffer_pages, xen_blkif_max_buffer_pages, int, 0644); MODULE_PARM_DESC(max_buffer_pages, "Maximum number of free pages to keep in each block backend buffer"); @@ -75,7 +75,7 @@ MODULE_PARM_DESC(max_buffer_pages, * algorithm. */ -static int xen_blkif_max_pgrants = 352; +static int xen_blkif_max_pgrants = 1056; module_param_named(max_persistent_grants, xen_blkif_max_pgrants, int, 0644); MODULE_PARM_DESC(max_persistent_grants, "Maximum number of grants to map persistently"); @@ -636,10 +636,6 @@ purge_gnt_list: return 0; } -struct seg_buf { - unsigned int offset; - unsigned int nsec; -}; /* * Unmap the grant references, and also remove the M2P over-rides * used in the 'pending_req'. @@ -818,29 +814,69 @@ out_of_memory: return -ENOMEM; } -static int xen_blkbk_map_seg(struct blkif_request *req, - struct pending_req *pending_req, +static int xen_blkbk_map_seg(struct pending_req *pending_req, struct seg_buf seg[], struct page *pages[]) { - int i, rc; - grant_ref_t grefs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + int rc; - for (i = 0; i < req->u.rw.nr_segments; i++) - grefs[i] = req->u.rw.seg[i].gref; - - rc = xen_blkbk_map(pending_req->blkif, grefs, + rc = xen_blkbk_map(pending_req->blkif, pending_req->grefs, pending_req->persistent_gnts, pending_req->grant_handles, pending_req->pages, - req->u.rw.nr_segments, + pending_req->nr_pages, (pending_req->operation != BLKIF_OP_READ)); - if (rc) - return rc; - for (i = 0; i < req->u.rw.nr_segments; i++) - seg[i].offset = (req->u.rw.seg[i].first_sect << 9); + return rc; +} - return 0; +static int xen_blkbk_parse_indirect(struct blkif_request *req, + struct pending_req *pending_req, + struct seg_buf seg[], + struct phys_req *preq) +{ + struct persistent_gnt **persistent = + pending_req->indirect_persistent_gnts; + struct page **pages = pending_req->indirect_pages; + struct xen_blkif *blkif = pending_req->blkif; + int indirect_grefs, rc, n, nseg, i; + struct blkif_request_segment_aligned *segments = NULL; + + nseg = pending_req->nr_pages; + indirect_grefs = INDIRECT_PAGES(nseg); + BUG_ON(indirect_grefs > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); + + rc = xen_blkbk_map(blkif, req->u.indirect.indirect_grefs, + persistent, pending_req->indirect_handles, + pages, indirect_grefs, true); + if (rc) + goto unmap; + + for (n = 0, i = 0; n < nseg; n++) { + if ((n % SEGS_PER_INDIRECT_FRAME) == 0) { + /* Map indirect segments */ + if (segments) + kunmap_atomic(segments); + segments = kmap_atomic(pages[n/SEGS_PER_INDIRECT_FRAME]); + } + i = n % SEGS_PER_INDIRECT_FRAME; + pending_req->grefs[n] = segments[i].gref; + seg[n].nsec = segments[i].last_sect - + segments[i].first_sect + 1; + seg[n].offset = (segments[i].first_sect << 9); + if ((segments[i].last_sect >= (PAGE_SIZE >> 9)) || + (segments[i].last_sect < segments[i].first_sect)) { + rc = -EINVAL; + goto unmap; + } + preq->nr_sects += seg[n].nsec; + } + +unmap: + if (segments) + kunmap_atomic(segments); + xen_blkbk_unmap(blkif, pending_req->indirect_handles, + pages, persistent, indirect_grefs); + return rc; } static int dispatch_discard_io(struct xen_blkif *blkif, @@ -1013,6 +1049,7 @@ __do_block_io_op(struct xen_blkif *blkif) case BLKIF_OP_WRITE: case BLKIF_OP_WRITE_BARRIER: case BLKIF_OP_FLUSH_DISKCACHE: + case BLKIF_OP_INDIRECT: if (dispatch_rw_block_io(blkif, &req, pending_req)) goto done; break; @@ -1059,17 +1096,28 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, struct pending_req *pending_req) { struct phys_req preq; - struct seg_buf seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + struct seg_buf *seg = pending_req->seg; unsigned int nseg; struct bio *bio = NULL; - struct bio *biolist[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + struct bio **biolist = pending_req->biolist; int i, nbio = 0; int operation; struct blk_plug plug; bool drain = false; struct page **pages = pending_req->pages; + unsigned short req_operation; + + req_operation = req->operation == BLKIF_OP_INDIRECT ? + req->u.indirect.indirect_op : req->operation; + if ((req->operation == BLKIF_OP_INDIRECT) && + (req_operation != BLKIF_OP_READ) && + (req_operation != BLKIF_OP_WRITE)) { + pr_debug(DRV_PFX "Invalid indirect operation (%u)\n", + req_operation); + goto fail_response; + } - switch (req->operation) { + switch (req_operation) { case BLKIF_OP_READ: blkif->st_rd_req++; operation = READ; @@ -1091,33 +1139,47 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, } /* Check that the number of segments is sane. */ - nseg = req->u.rw.nr_segments; + nseg = req->operation == BLKIF_OP_INDIRECT ? + req->u.indirect.nr_segments : req->u.rw.nr_segments; if (unlikely(nseg == 0 && operation != WRITE_FLUSH) || - unlikely(nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) { + unlikely((req->operation != BLKIF_OP_INDIRECT) && + (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) || + unlikely((req->operation == BLKIF_OP_INDIRECT) && + (nseg > MAX_INDIRECT_SEGMENTS))) { pr_debug(DRV_PFX "Bad number of segments in request (%d)\n", nseg); /* Haven't submitted any bio's yet. */ goto fail_response; } - preq.sector_number = req->u.rw.sector_number; preq.nr_sects = 0; pending_req->blkif = blkif; pending_req->id = req->u.rw.id; - pending_req->operation = req->operation; + pending_req->operation = req_operation; pending_req->status = BLKIF_RSP_OKAY; pending_req->nr_pages = nseg; - for (i = 0; i < nseg; i++) { - seg[i].nsec = req->u.rw.seg[i].last_sect - - req->u.rw.seg[i].first_sect + 1; - if ((req->u.rw.seg[i].last_sect >= (PAGE_SIZE >> 9)) || - (req->u.rw.seg[i].last_sect < req->u.rw.seg[i].first_sect)) + if (req->operation != BLKIF_OP_INDIRECT) { + preq.dev = req->u.rw.handle; + preq.sector_number = req->u.rw.sector_number; + for (i = 0; i < nseg; i++) { + pending_req->grefs[i] = req->u.rw.seg[i].gref; + seg[i].nsec = req->u.rw.seg[i].last_sect - + req->u.rw.seg[i].first_sect + 1; + seg[i].offset = (req->u.rw.seg[i].first_sect << 9); + if ((req->u.rw.seg[i].last_sect >= (PAGE_SIZE >> 9)) || + (req->u.rw.seg[i].last_sect < + req->u.rw.seg[i].first_sect)) + goto fail_response; + preq.nr_sects += seg[i].nsec; + } + } else { + preq.dev = req->u.indirect.handle; + preq.sector_number = req->u.indirect.sector_number; + if (xen_blkbk_parse_indirect(req, pending_req, seg, &preq)) goto fail_response; - preq.nr_sects += seg[i].nsec; - } if (xen_vbd_translate(&preq, blkif, operation) != 0) { @@ -1154,7 +1216,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, * the hypercall to unmap the grants - that is all done in * xen_blkbk_unmap. */ - if (xen_blkbk_map_seg(req, pending_req, seg, pages)) + if (xen_blkbk_map_seg(pending_req, seg, pages)) goto fail_flush; /* @@ -1220,7 +1282,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, pending_req->nr_pages); fail_response: /* Haven't submitted any bio's yet. */ - make_response(blkif, req->u.rw.id, req->operation, BLKIF_RSP_ERROR); + make_response(blkif, req->u.rw.id, req_operation, BLKIF_RSP_ERROR); free_req(blkif, pending_req); msleep(1); /* back off a bit */ return -EIO; diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index e33fafa0facd..1ac53da8410f 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -50,6 +50,19 @@ __func__, __LINE__, ##args) +/* + * This is the maximum number of segments that would be allowed in indirect + * requests. This value will also be passed to the frontend. + */ +#define MAX_INDIRECT_SEGMENTS 256 + +#define SEGS_PER_INDIRECT_FRAME \ + (PAGE_SIZE/sizeof(struct blkif_request_segment_aligned)) +#define MAX_INDIRECT_PAGES \ + ((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) +#define INDIRECT_PAGES(_segs) \ + ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) + /* Not a real protocol. Used to generate ring structs which contain * the elements common to all protocols only. This way we get a * compiler-checkable way to use common struct elements, so we can @@ -83,12 +96,31 @@ struct blkif_x86_32_request_other { uint64_t id; /* private guest value, echoed in resp */ } __attribute__((__packed__)); +struct blkif_x86_32_request_indirect { + uint8_t indirect_op; + uint16_t nr_segments; + uint64_t id; + blkif_sector_t sector_number; + blkif_vdev_t handle; + uint16_t _pad1; + grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST]; + /* + * The maximum number of indirect segments (and pages) that will + * be used is determined by MAX_INDIRECT_SEGMENTS, this value + * is also exported to the guest (via xenstore + * feature-max-indirect-segments entry), so the frontend knows how + * many indirect segments the backend supports. + */ + uint64_t _pad2; /* make it 64 byte aligned */ +} __attribute__((__packed__)); + struct blkif_x86_32_request { uint8_t operation; /* BLKIF_OP_??? */ union { struct blkif_x86_32_request_rw rw; struct blkif_x86_32_request_discard discard; struct blkif_x86_32_request_other other; + struct blkif_x86_32_request_indirect indirect; } u; } __attribute__((__packed__)); @@ -127,12 +159,32 @@ struct blkif_x86_64_request_other { uint64_t id; /* private guest value, echoed in resp */ } __attribute__((__packed__)); +struct blkif_x86_64_request_indirect { + uint8_t indirect_op; + uint16_t nr_segments; + uint32_t _pad1; /* offsetof(blkif_..,u.indirect.id)==8 */ + uint64_t id; + blkif_sector_t sector_number; + blkif_vdev_t handle; + uint16_t _pad2; + grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST]; + /* + * The maximum number of indirect segments (and pages) that will + * be used is determined by MAX_INDIRECT_SEGMENTS, this value + * is also exported to the guest (via xenstore + * feature-max-indirect-segments entry), so the frontend knows how + * many indirect segments the backend supports. + */ + uint32_t _pad3; /* make it 64 byte aligned */ +} __attribute__((__packed__)); + struct blkif_x86_64_request { uint8_t operation; /* BLKIF_OP_??? */ union { struct blkif_x86_64_request_rw rw; struct blkif_x86_64_request_discard discard; struct blkif_x86_64_request_other other; + struct blkif_x86_64_request_indirect indirect; } u; } __attribute__((__packed__)); @@ -266,6 +318,11 @@ struct xen_blkif { wait_queue_head_t waiting_to_free; }; +struct seg_buf { + unsigned long offset; + unsigned int nsec; +}; + /* * Each outstanding request that we've passed to the lower device layers has a * 'pending_req' allocated to it. Each buffer_head that completes decrements @@ -280,9 +337,16 @@ struct pending_req { unsigned short operation; int status; struct list_head free_list; - struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - struct persistent_gnt *persistent_gnts[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - grant_handle_t grant_handles[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + struct page *pages[MAX_INDIRECT_SEGMENTS]; + struct persistent_gnt *persistent_gnts[MAX_INDIRECT_SEGMENTS]; + grant_handle_t grant_handles[MAX_INDIRECT_SEGMENTS]; + grant_ref_t grefs[MAX_INDIRECT_SEGMENTS]; + /* Indirect descriptors */ + struct persistent_gnt *indirect_persistent_gnts[MAX_INDIRECT_PAGES]; + struct page *indirect_pages[MAX_INDIRECT_PAGES]; + grant_handle_t indirect_handles[MAX_INDIRECT_PAGES]; + struct seg_buf seg[MAX_INDIRECT_SEGMENTS]; + struct bio *biolist[MAX_INDIRECT_SEGMENTS]; }; @@ -321,7 +385,7 @@ struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be); static inline void blkif_get_x86_32_req(struct blkif_request *dst, struct blkif_x86_32_request *src) { - int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; + int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j; dst->operation = src->operation; switch (src->operation) { case BLKIF_OP_READ: @@ -344,6 +408,18 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst, dst->u.discard.sector_number = src->u.discard.sector_number; dst->u.discard.nr_sectors = src->u.discard.nr_sectors; break; + case BLKIF_OP_INDIRECT: + dst->u.indirect.indirect_op = src->u.indirect.indirect_op; + dst->u.indirect.nr_segments = src->u.indirect.nr_segments; + dst->u.indirect.handle = src->u.indirect.handle; + dst->u.indirect.id = src->u.indirect.id; + dst->u.indirect.sector_number = src->u.indirect.sector_number; + barrier(); + j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments)); + for (i = 0; i < j; i++) + dst->u.indirect.indirect_grefs[i] = + src->u.indirect.indirect_grefs[i]; + break; default: /* * Don't know how to translate this op. Only get the @@ -357,7 +433,7 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst, static inline void blkif_get_x86_64_req(struct blkif_request *dst, struct blkif_x86_64_request *src) { - int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; + int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j; dst->operation = src->operation; switch (src->operation) { case BLKIF_OP_READ: @@ -380,6 +456,18 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst, dst->u.discard.sector_number = src->u.discard.sector_number; dst->u.discard.nr_sectors = src->u.discard.nr_sectors; break; + case BLKIF_OP_INDIRECT: + dst->u.indirect.indirect_op = src->u.indirect.indirect_op; + dst->u.indirect.nr_segments = src->u.indirect.nr_segments; + dst->u.indirect.handle = src->u.indirect.handle; + dst->u.indirect.id = src->u.indirect.id; + dst->u.indirect.sector_number = src->u.indirect.sector_number; + barrier(); + j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments)); + for (i = 0; i < j; i++) + dst->u.indirect.indirect_grefs[i] = + src->u.indirect.indirect_grefs[i]; + break; default: /* * Don't know how to translate this op. Only get the diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 1f1ade6d6e09..afab208c54e3 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -107,6 +107,8 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid) struct xen_blkif *blkif; int i; + BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); + blkif = kmem_cache_zalloc(xen_blkif_cachep, GFP_KERNEL); if (!blkif) return ERR_PTR(-ENOMEM); @@ -709,6 +711,11 @@ again: dev->nodename); goto abort; } + err = xenbus_printf(xbt, dev->nodename, "feature-max-indirect-segments", "%u", + MAX_INDIRECT_SEGMENTS); + if (err) + dev_warn(&dev->dev, "writing %s/feature-max-indirect-segments (%d)", + dev->nodename, err); err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", (unsigned long long)vbd_sz(&be->blkif->vbd)); |