14f1043b4SStefan Hajnoczi /* 24f1043b4SStefan Hajnoczi * Image streaming 34f1043b4SStefan Hajnoczi * 44f1043b4SStefan Hajnoczi * Copyright IBM, Corp. 2011 54f1043b4SStefan Hajnoczi * 64f1043b4SStefan Hajnoczi * Authors: 74f1043b4SStefan Hajnoczi * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 84f1043b4SStefan Hajnoczi * 94f1043b4SStefan Hajnoczi * This work is licensed under the terms of the GNU LGPL, version 2 or later. 104f1043b4SStefan Hajnoczi * See the COPYING.LIB file in the top-level directory. 114f1043b4SStefan Hajnoczi * 124f1043b4SStefan Hajnoczi */ 134f1043b4SStefan Hajnoczi 144f1043b4SStefan Hajnoczi #include "trace.h" 15737e150eSPaolo Bonzini #include "block/block_int.h" 16737e150eSPaolo Bonzini #include "block/blockjob.h" 176ef228fcSPaolo Bonzini #include "qemu/ratelimit.h" 184f1043b4SStefan Hajnoczi 194f1043b4SStefan Hajnoczi enum { 204f1043b4SStefan Hajnoczi /* 214f1043b4SStefan Hajnoczi * Size of data buffer for populating the image file. This should be large 224f1043b4SStefan Hajnoczi * enough to process multiple clusters in a single call, so that populating 234f1043b4SStefan Hajnoczi * contiguous regions of the image is efficient. 244f1043b4SStefan Hajnoczi */ 254f1043b4SStefan Hajnoczi STREAM_BUFFER_SIZE = 512 * 1024, /* in bytes */ 264f1043b4SStefan Hajnoczi }; 274f1043b4SStefan Hajnoczi 285094a6c0SStefan Hajnoczi #define SLICE_TIME 100000000ULL /* ns */ 295094a6c0SStefan Hajnoczi 304f1043b4SStefan Hajnoczi typedef struct StreamBlockJob { 314f1043b4SStefan Hajnoczi BlockJob common; 325094a6c0SStefan Hajnoczi RateLimit limit; 334f1043b4SStefan Hajnoczi BlockDriverState *base; 341d809098SPaolo Bonzini BlockdevOnError on_error; 35c8c3080fSMarcelo Tosatti char backing_file_id[1024]; 364f1043b4SStefan Hajnoczi } StreamBlockJob; 374f1043b4SStefan Hajnoczi 384f1043b4SStefan Hajnoczi static int coroutine_fn stream_populate(BlockDriverState *bs, 394f1043b4SStefan Hajnoczi int64_t sector_num, int nb_sectors, 404f1043b4SStefan Hajnoczi void *buf) 414f1043b4SStefan Hajnoczi { 424f1043b4SStefan Hajnoczi struct iovec iov = { 434f1043b4SStefan Hajnoczi .iov_base = buf, 444f1043b4SStefan Hajnoczi .iov_len = nb_sectors * BDRV_SECTOR_SIZE, 454f1043b4SStefan Hajnoczi }; 464f1043b4SStefan Hajnoczi QEMUIOVector qiov; 474f1043b4SStefan Hajnoczi 484f1043b4SStefan Hajnoczi qemu_iovec_init_external(&qiov, &iov, 1); 494f1043b4SStefan Hajnoczi 504f1043b4SStefan Hajnoczi /* Copy-on-read the unallocated clusters */ 514f1043b4SStefan Hajnoczi return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov); 524f1043b4SStefan Hajnoczi } 534f1043b4SStefan Hajnoczi 545a67a104SMarcelo Tosatti static void close_unused_images(BlockDriverState *top, BlockDriverState *base, 555a67a104SMarcelo Tosatti const char *base_id) 565a67a104SMarcelo Tosatti { 575a67a104SMarcelo Tosatti BlockDriverState *intermediate; 585a67a104SMarcelo Tosatti intermediate = top->backing_hd; 595a67a104SMarcelo Tosatti 6088266f5aSStefan Hajnoczi /* Must assign before bdrv_delete() to prevent traversing dangling pointer 6188266f5aSStefan Hajnoczi * while we delete backing image instances. 6288266f5aSStefan Hajnoczi */ 6388266f5aSStefan Hajnoczi top->backing_hd = base; 6488266f5aSStefan Hajnoczi 655a67a104SMarcelo Tosatti while (intermediate) { 665a67a104SMarcelo Tosatti BlockDriverState *unused; 675a67a104SMarcelo Tosatti 685a67a104SMarcelo Tosatti /* reached base */ 695a67a104SMarcelo Tosatti if (intermediate == base) { 705a67a104SMarcelo Tosatti break; 715a67a104SMarcelo Tosatti } 725a67a104SMarcelo Tosatti 735a67a104SMarcelo Tosatti unused = intermediate; 745a67a104SMarcelo Tosatti intermediate = intermediate->backing_hd; 755a67a104SMarcelo Tosatti unused->backing_hd = NULL; 764f6fd349SFam Zheng bdrv_unref(unused); 775a67a104SMarcelo Tosatti } 785a67a104SMarcelo Tosatti } 795a67a104SMarcelo Tosatti 804f1043b4SStefan Hajnoczi static void coroutine_fn stream_run(void *opaque) 814f1043b4SStefan Hajnoczi { 824f1043b4SStefan Hajnoczi StreamBlockJob *s = opaque; 834f1043b4SStefan Hajnoczi BlockDriverState *bs = s->common.bs; 84c8c3080fSMarcelo Tosatti BlockDriverState *base = s->base; 854f1043b4SStefan Hajnoczi int64_t sector_num, end; 861d809098SPaolo Bonzini int error = 0; 874f1043b4SStefan Hajnoczi int ret = 0; 8804120e3bSAnthony Liguori int n = 0; 894f1043b4SStefan Hajnoczi void *buf; 904f1043b4SStefan Hajnoczi 914f1043b4SStefan Hajnoczi s->common.len = bdrv_getlength(bs); 924f1043b4SStefan Hajnoczi if (s->common.len < 0) { 9365f46322SPaolo Bonzini block_job_completed(&s->common, s->common.len); 944f1043b4SStefan Hajnoczi return; 954f1043b4SStefan Hajnoczi } 964f1043b4SStefan Hajnoczi 974f1043b4SStefan Hajnoczi end = s->common.len >> BDRV_SECTOR_BITS; 984f1043b4SStefan Hajnoczi buf = qemu_blockalign(bs, STREAM_BUFFER_SIZE); 994f1043b4SStefan Hajnoczi 1004f1043b4SStefan Hajnoczi /* Turn on copy-on-read for the whole block device so that guest read 1014f1043b4SStefan Hajnoczi * requests help us make progress. Only do this when copying the entire 1024f1043b4SStefan Hajnoczi * backing chain since the copy-on-read operation does not take base into 1034f1043b4SStefan Hajnoczi * account. 1044f1043b4SStefan Hajnoczi */ 1054f1043b4SStefan Hajnoczi if (!base) { 1064f1043b4SStefan Hajnoczi bdrv_enable_copy_on_read(bs); 1074f1043b4SStefan Hajnoczi } 1084f1043b4SStefan Hajnoczi 1094f1043b4SStefan Hajnoczi for (sector_num = 0; sector_num < end; sector_num += n) { 1104513eafeSPaolo Bonzini uint64_t delay_ns = 0; 111f9749f28SPaolo Bonzini bool copy; 1124513eafeSPaolo Bonzini 1134513eafeSPaolo Bonzini wait: 1144513eafeSPaolo Bonzini /* Note that even when no rate limit is applied we need to yield 115c57b6656SKevin Wolf * with no pending I/O here so that bdrv_drain_all() returns. 1164513eafeSPaolo Bonzini */ 1177483d1e5SAlex Bligh block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); 1184f1043b4SStefan Hajnoczi if (block_job_is_cancelled(&s->common)) { 1194f1043b4SStefan Hajnoczi break; 1204f1043b4SStefan Hajnoczi } 1214f1043b4SStefan Hajnoczi 122c3e4f43aSStefan Weil copy = false; 123c3e4f43aSStefan Weil 124bdad13b9SPaolo Bonzini ret = bdrv_is_allocated(bs, sector_num, 1254f1043b4SStefan Hajnoczi STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n); 126f9749f28SPaolo Bonzini if (ret == 1) { 127f9749f28SPaolo Bonzini /* Allocated in the top, no need to copy. */ 128d663640cSPaolo Bonzini } else if (ret >= 0) { 129f9749f28SPaolo Bonzini /* Copy if allocated in the intermediate images. Limit to the 130f9749f28SPaolo Bonzini * known-unallocated area [sector_num, sector_num+n). */ 1314f578637SPaolo Bonzini ret = bdrv_is_allocated_above(bs->backing_hd, base, 132188a7bbfSPaolo Bonzini sector_num, n, &n); 133571cd9dcSStefan Hajnoczi 134571cd9dcSStefan Hajnoczi /* Finish early if end of backing file has been reached */ 135571cd9dcSStefan Hajnoczi if (ret == 0 && n == 0) { 136571cd9dcSStefan Hajnoczi n = end - sector_num; 137571cd9dcSStefan Hajnoczi } 138571cd9dcSStefan Hajnoczi 139f9749f28SPaolo Bonzini copy = (ret == 1); 140f9749f28SPaolo Bonzini } 1414f1043b4SStefan Hajnoczi trace_stream_one_iteration(s, sector_num, n, ret); 142c3e4f43aSStefan Weil if (copy) { 1435094a6c0SStefan Hajnoczi if (s->common.speed) { 1444513eafeSPaolo Bonzini delay_ns = ratelimit_calculate_delay(&s->limit, n); 1455094a6c0SStefan Hajnoczi if (delay_ns > 0) { 1464513eafeSPaolo Bonzini goto wait; 1475094a6c0SStefan Hajnoczi } 1485094a6c0SStefan Hajnoczi } 1494f1043b4SStefan Hajnoczi ret = stream_populate(bs, sector_num, n, buf); 1504f1043b4SStefan Hajnoczi } 1514f1043b4SStefan Hajnoczi if (ret < 0) { 1521d809098SPaolo Bonzini BlockErrorAction action = 1531d809098SPaolo Bonzini block_job_error_action(&s->common, s->common.bs, s->on_error, 1541d809098SPaolo Bonzini true, -ret); 1551d809098SPaolo Bonzini if (action == BDRV_ACTION_STOP) { 1561d809098SPaolo Bonzini n = 0; 1571d809098SPaolo Bonzini continue; 1581d809098SPaolo Bonzini } 1591d809098SPaolo Bonzini if (error == 0) { 1601d809098SPaolo Bonzini error = ret; 1611d809098SPaolo Bonzini } 1621d809098SPaolo Bonzini if (action == BDRV_ACTION_REPORT) { 1634f1043b4SStefan Hajnoczi break; 1644f1043b4SStefan Hajnoczi } 1651d809098SPaolo Bonzini } 166c8c3080fSMarcelo Tosatti ret = 0; 1674f1043b4SStefan Hajnoczi 1684f1043b4SStefan Hajnoczi /* Publish progress */ 1694f1043b4SStefan Hajnoczi s->common.offset += n * BDRV_SECTOR_SIZE; 1704f1043b4SStefan Hajnoczi } 1714f1043b4SStefan Hajnoczi 1724f1043b4SStefan Hajnoczi if (!base) { 1734f1043b4SStefan Hajnoczi bdrv_disable_copy_on_read(bs); 1744f1043b4SStefan Hajnoczi } 1754f1043b4SStefan Hajnoczi 1761d809098SPaolo Bonzini /* Do not remove the backing file if an error was there but ignored. */ 1771d809098SPaolo Bonzini ret = error; 1781d809098SPaolo Bonzini 1793e914655SPaolo Bonzini if (!block_job_is_cancelled(&s->common) && sector_num == end && ret == 0) { 180f6133defSPaolo Bonzini const char *base_id = NULL, *base_fmt = NULL; 181c8c3080fSMarcelo Tosatti if (base) { 182c8c3080fSMarcelo Tosatti base_id = s->backing_file_id; 183f6133defSPaolo Bonzini if (base->drv) { 184f6133defSPaolo Bonzini base_fmt = base->drv->format_name; 185c8c3080fSMarcelo Tosatti } 186f6133defSPaolo Bonzini } 187f6133defSPaolo Bonzini ret = bdrv_change_backing_file(bs, base_id, base_fmt); 1885a67a104SMarcelo Tosatti close_unused_images(bs, base, base_id); 1894f1043b4SStefan Hajnoczi } 1904f1043b4SStefan Hajnoczi 1914f1043b4SStefan Hajnoczi qemu_vfree(buf); 19265f46322SPaolo Bonzini block_job_completed(&s->common, ret); 1934f1043b4SStefan Hajnoczi } 1944f1043b4SStefan Hajnoczi 195882ec7ceSStefan Hajnoczi static void stream_set_speed(BlockJob *job, int64_t speed, Error **errp) 1965094a6c0SStefan Hajnoczi { 1975094a6c0SStefan Hajnoczi StreamBlockJob *s = container_of(job, StreamBlockJob, common); 1985094a6c0SStefan Hajnoczi 199882ec7ceSStefan Hajnoczi if (speed < 0) { 200882ec7ceSStefan Hajnoczi error_set(errp, QERR_INVALID_PARAMETER, "speed"); 2019e6636c7SStefan Hajnoczi return; 2025094a6c0SStefan Hajnoczi } 2036ef228fcSPaolo Bonzini ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME); 2045094a6c0SStefan Hajnoczi } 2055094a6c0SStefan Hajnoczi 2063fc4b10aSFam Zheng static const BlockJobDriver stream_job_driver = { 2074f1043b4SStefan Hajnoczi .instance_size = sizeof(StreamBlockJob), 208*79e14bf7SFam Zheng .job_type = BLOCK_JOB_TYPE_STREAM, 2095094a6c0SStefan Hajnoczi .set_speed = stream_set_speed, 2104f1043b4SStefan Hajnoczi }; 2114f1043b4SStefan Hajnoczi 212fd7f8c65SStefan Hajnoczi void stream_start(BlockDriverState *bs, BlockDriverState *base, 213c83c66c3SStefan Hajnoczi const char *base_id, int64_t speed, 2141d809098SPaolo Bonzini BlockdevOnError on_error, 215c83c66c3SStefan Hajnoczi BlockDriverCompletionFunc *cb, 216fd7f8c65SStefan Hajnoczi void *opaque, Error **errp) 2174f1043b4SStefan Hajnoczi { 2184f1043b4SStefan Hajnoczi StreamBlockJob *s; 2194f1043b4SStefan Hajnoczi 2201d809098SPaolo Bonzini if ((on_error == BLOCKDEV_ON_ERROR_STOP || 2211d809098SPaolo Bonzini on_error == BLOCKDEV_ON_ERROR_ENOSPC) && 2221d809098SPaolo Bonzini !bdrv_iostatus_is_enabled(bs)) { 2231d809098SPaolo Bonzini error_set(errp, QERR_INVALID_PARAMETER, "on-error"); 2241d809098SPaolo Bonzini return; 2251d809098SPaolo Bonzini } 2261d809098SPaolo Bonzini 2273fc4b10aSFam Zheng s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp); 2284f1043b4SStefan Hajnoczi if (!s) { 229fd7f8c65SStefan Hajnoczi return; 2304f1043b4SStefan Hajnoczi } 2314f1043b4SStefan Hajnoczi 2324f1043b4SStefan Hajnoczi s->base = base; 233c8c3080fSMarcelo Tosatti if (base_id) { 234c8c3080fSMarcelo Tosatti pstrcpy(s->backing_file_id, sizeof(s->backing_file_id), base_id); 235c8c3080fSMarcelo Tosatti } 2364f1043b4SStefan Hajnoczi 2371d809098SPaolo Bonzini s->on_error = on_error; 238fa4478d5SPaolo Bonzini s->common.co = qemu_coroutine_create(stream_run); 239fa4478d5SPaolo Bonzini trace_stream_start(bs, base, s, s->common.co, opaque); 240fa4478d5SPaolo Bonzini qemu_coroutine_enter(s->common.co, s); 2414f1043b4SStefan Hajnoczi } 242