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 1480c71a24SPeter Maydell #include "qemu/osdep.h" 154f1043b4SStefan Hajnoczi #include "trace.h" 16737e150eSPaolo Bonzini #include "block/block_int.h" 17737e150eSPaolo Bonzini #include "block/blockjob.h" 18cc7a8ea7SMarkus Armbruster #include "qapi/qmp/qerror.h" 196ef228fcSPaolo Bonzini #include "qemu/ratelimit.h" 20373340b2SMax Reitz #include "sysemu/block-backend.h" 214f1043b4SStefan Hajnoczi 224f1043b4SStefan Hajnoczi enum { 234f1043b4SStefan Hajnoczi /* 244f1043b4SStefan Hajnoczi * Size of data buffer for populating the image file. This should be large 254f1043b4SStefan Hajnoczi * enough to process multiple clusters in a single call, so that populating 264f1043b4SStefan Hajnoczi * contiguous regions of the image is efficient. 274f1043b4SStefan Hajnoczi */ 284f1043b4SStefan Hajnoczi STREAM_BUFFER_SIZE = 512 * 1024, /* in bytes */ 294f1043b4SStefan Hajnoczi }; 304f1043b4SStefan Hajnoczi 315094a6c0SStefan Hajnoczi #define SLICE_TIME 100000000ULL /* ns */ 325094a6c0SStefan Hajnoczi 334f1043b4SStefan Hajnoczi typedef struct StreamBlockJob { 344f1043b4SStefan Hajnoczi BlockJob common; 355094a6c0SStefan Hajnoczi RateLimit limit; 364f1043b4SStefan Hajnoczi BlockDriverState *base; 371d809098SPaolo Bonzini BlockdevOnError on_error; 3813d8cc51SJeff Cody char *backing_file_str; 394f1043b4SStefan Hajnoczi } StreamBlockJob; 404f1043b4SStefan Hajnoczi 414f1043b4SStefan Hajnoczi static int coroutine_fn stream_populate(BlockDriverState *bs, 424f1043b4SStefan Hajnoczi int64_t sector_num, int nb_sectors, 434f1043b4SStefan Hajnoczi void *buf) 444f1043b4SStefan Hajnoczi { 454f1043b4SStefan Hajnoczi struct iovec iov = { 464f1043b4SStefan Hajnoczi .iov_base = buf, 474f1043b4SStefan Hajnoczi .iov_len = nb_sectors * BDRV_SECTOR_SIZE, 484f1043b4SStefan Hajnoczi }; 494f1043b4SStefan Hajnoczi QEMUIOVector qiov; 504f1043b4SStefan Hajnoczi 514f1043b4SStefan Hajnoczi qemu_iovec_init_external(&qiov, &iov, 1); 524f1043b4SStefan Hajnoczi 534f1043b4SStefan Hajnoczi /* Copy-on-read the unallocated clusters */ 544f1043b4SStefan Hajnoczi return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov); 554f1043b4SStefan Hajnoczi } 564f1043b4SStefan Hajnoczi 57f3e69bebSStefan Hajnoczi typedef struct { 58f3e69bebSStefan Hajnoczi int ret; 59f3e69bebSStefan Hajnoczi bool reached_end; 60f3e69bebSStefan Hajnoczi } StreamCompleteData; 61f3e69bebSStefan Hajnoczi 62f3e69bebSStefan Hajnoczi static void stream_complete(BlockJob *job, void *opaque) 63f3e69bebSStefan Hajnoczi { 64f3e69bebSStefan Hajnoczi StreamBlockJob *s = container_of(job, StreamBlockJob, common); 65f3e69bebSStefan Hajnoczi StreamCompleteData *data = opaque; 66f3e69bebSStefan Hajnoczi BlockDriverState *base = s->base; 67f3e69bebSStefan Hajnoczi 68f3e69bebSStefan Hajnoczi if (!block_job_is_cancelled(&s->common) && data->reached_end && 69f3e69bebSStefan Hajnoczi data->ret == 0) { 70f3e69bebSStefan Hajnoczi const char *base_id = NULL, *base_fmt = NULL; 71f3e69bebSStefan Hajnoczi if (base) { 72f3e69bebSStefan Hajnoczi base_id = s->backing_file_str; 73f3e69bebSStefan Hajnoczi if (base->drv) { 74f3e69bebSStefan Hajnoczi base_fmt = base->drv->format_name; 75f3e69bebSStefan Hajnoczi } 76f3e69bebSStefan Hajnoczi } 77f3e69bebSStefan Hajnoczi data->ret = bdrv_change_backing_file(job->bs, base_id, base_fmt); 785db15a57SKevin Wolf bdrv_set_backing_hd(job->bs, base); 79f3e69bebSStefan Hajnoczi } 80f3e69bebSStefan Hajnoczi 81f3e69bebSStefan Hajnoczi g_free(s->backing_file_str); 82f3e69bebSStefan Hajnoczi block_job_completed(&s->common, data->ret); 83f3e69bebSStefan Hajnoczi g_free(data); 84f3e69bebSStefan Hajnoczi } 85f3e69bebSStefan Hajnoczi 864f1043b4SStefan Hajnoczi static void coroutine_fn stream_run(void *opaque) 874f1043b4SStefan Hajnoczi { 884f1043b4SStefan Hajnoczi StreamBlockJob *s = opaque; 89f3e69bebSStefan Hajnoczi StreamCompleteData *data; 904f1043b4SStefan Hajnoczi BlockDriverState *bs = s->common.bs; 91c8c3080fSMarcelo Tosatti BlockDriverState *base = s->base; 92*6578629eSAlberto Garcia int64_t sector_num = 0; 93*6578629eSAlberto Garcia int64_t end = -1; 941d809098SPaolo Bonzini int error = 0; 954f1043b4SStefan Hajnoczi int ret = 0; 9604120e3bSAnthony Liguori int n = 0; 974f1043b4SStefan Hajnoczi void *buf; 984f1043b4SStefan Hajnoczi 99760e0063SKevin Wolf if (!bs->backing) { 100*6578629eSAlberto Garcia goto out; 101f4a193e7SMax Reitz } 102f4a193e7SMax Reitz 1034f1043b4SStefan Hajnoczi s->common.len = bdrv_getlength(bs); 1044f1043b4SStefan Hajnoczi if (s->common.len < 0) { 105*6578629eSAlberto Garcia ret = s->common.len; 106*6578629eSAlberto Garcia goto out; 1074f1043b4SStefan Hajnoczi } 1084f1043b4SStefan Hajnoczi 1094f1043b4SStefan Hajnoczi end = s->common.len >> BDRV_SECTOR_BITS; 1104f1043b4SStefan Hajnoczi buf = qemu_blockalign(bs, STREAM_BUFFER_SIZE); 1114f1043b4SStefan Hajnoczi 1124f1043b4SStefan Hajnoczi /* Turn on copy-on-read for the whole block device so that guest read 1134f1043b4SStefan Hajnoczi * requests help us make progress. Only do this when copying the entire 1144f1043b4SStefan Hajnoczi * backing chain since the copy-on-read operation does not take base into 1154f1043b4SStefan Hajnoczi * account. 1164f1043b4SStefan Hajnoczi */ 1174f1043b4SStefan Hajnoczi if (!base) { 1184f1043b4SStefan Hajnoczi bdrv_enable_copy_on_read(bs); 1194f1043b4SStefan Hajnoczi } 1204f1043b4SStefan Hajnoczi 1214f1043b4SStefan Hajnoczi for (sector_num = 0; sector_num < end; sector_num += n) { 1224513eafeSPaolo Bonzini uint64_t delay_ns = 0; 123f9749f28SPaolo Bonzini bool copy; 1244513eafeSPaolo Bonzini 1254513eafeSPaolo Bonzini wait: 1264513eafeSPaolo Bonzini /* Note that even when no rate limit is applied we need to yield 127c57b6656SKevin Wolf * with no pending I/O here so that bdrv_drain_all() returns. 1284513eafeSPaolo Bonzini */ 1297483d1e5SAlex Bligh block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); 1304f1043b4SStefan Hajnoczi if (block_job_is_cancelled(&s->common)) { 1314f1043b4SStefan Hajnoczi break; 1324f1043b4SStefan Hajnoczi } 1334f1043b4SStefan Hajnoczi 134c3e4f43aSStefan Weil copy = false; 135c3e4f43aSStefan Weil 136bdad13b9SPaolo Bonzini ret = bdrv_is_allocated(bs, sector_num, 1374f1043b4SStefan Hajnoczi STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n); 138f9749f28SPaolo Bonzini if (ret == 1) { 139f9749f28SPaolo Bonzini /* Allocated in the top, no need to copy. */ 140d663640cSPaolo Bonzini } else if (ret >= 0) { 141f9749f28SPaolo Bonzini /* Copy if allocated in the intermediate images. Limit to the 142f9749f28SPaolo Bonzini * known-unallocated area [sector_num, sector_num+n). */ 143760e0063SKevin Wolf ret = bdrv_is_allocated_above(backing_bs(bs), base, 144188a7bbfSPaolo Bonzini sector_num, n, &n); 145571cd9dcSStefan Hajnoczi 146571cd9dcSStefan Hajnoczi /* Finish early if end of backing file has been reached */ 147571cd9dcSStefan Hajnoczi if (ret == 0 && n == 0) { 148571cd9dcSStefan Hajnoczi n = end - sector_num; 149571cd9dcSStefan Hajnoczi } 150571cd9dcSStefan Hajnoczi 151f9749f28SPaolo Bonzini copy = (ret == 1); 152f9749f28SPaolo Bonzini } 1534f1043b4SStefan Hajnoczi trace_stream_one_iteration(s, sector_num, n, ret); 154c3e4f43aSStefan Weil if (copy) { 1555094a6c0SStefan Hajnoczi if (s->common.speed) { 1564513eafeSPaolo Bonzini delay_ns = ratelimit_calculate_delay(&s->limit, n); 1575094a6c0SStefan Hajnoczi if (delay_ns > 0) { 1584513eafeSPaolo Bonzini goto wait; 1595094a6c0SStefan Hajnoczi } 1605094a6c0SStefan Hajnoczi } 1614f1043b4SStefan Hajnoczi ret = stream_populate(bs, sector_num, n, buf); 1624f1043b4SStefan Hajnoczi } 1634f1043b4SStefan Hajnoczi if (ret < 0) { 1641d809098SPaolo Bonzini BlockErrorAction action = 1651d809098SPaolo Bonzini block_job_error_action(&s->common, s->common.bs, s->on_error, 1661d809098SPaolo Bonzini true, -ret); 167a589569fSWenchao Xia if (action == BLOCK_ERROR_ACTION_STOP) { 1681d809098SPaolo Bonzini n = 0; 1691d809098SPaolo Bonzini continue; 1701d809098SPaolo Bonzini } 1711d809098SPaolo Bonzini if (error == 0) { 1721d809098SPaolo Bonzini error = ret; 1731d809098SPaolo Bonzini } 174a589569fSWenchao Xia if (action == BLOCK_ERROR_ACTION_REPORT) { 1754f1043b4SStefan Hajnoczi break; 1764f1043b4SStefan Hajnoczi } 1771d809098SPaolo Bonzini } 178c8c3080fSMarcelo Tosatti ret = 0; 1794f1043b4SStefan Hajnoczi 1804f1043b4SStefan Hajnoczi /* Publish progress */ 1814f1043b4SStefan Hajnoczi s->common.offset += n * BDRV_SECTOR_SIZE; 1824f1043b4SStefan Hajnoczi } 1834f1043b4SStefan Hajnoczi 1844f1043b4SStefan Hajnoczi if (!base) { 1854f1043b4SStefan Hajnoczi bdrv_disable_copy_on_read(bs); 1864f1043b4SStefan Hajnoczi } 1874f1043b4SStefan Hajnoczi 1881d809098SPaolo Bonzini /* Do not remove the backing file if an error was there but ignored. */ 1891d809098SPaolo Bonzini ret = error; 1901d809098SPaolo Bonzini 1914f1043b4SStefan Hajnoczi qemu_vfree(buf); 192f3e69bebSStefan Hajnoczi 193*6578629eSAlberto Garcia out: 194f3e69bebSStefan Hajnoczi /* Modify backing chain and close BDSes in main loop */ 195f3e69bebSStefan Hajnoczi data = g_malloc(sizeof(*data)); 196f3e69bebSStefan Hajnoczi data->ret = ret; 197f3e69bebSStefan Hajnoczi data->reached_end = sector_num == end; 198f3e69bebSStefan Hajnoczi block_job_defer_to_main_loop(&s->common, stream_complete, data); 1994f1043b4SStefan Hajnoczi } 2004f1043b4SStefan Hajnoczi 201882ec7ceSStefan Hajnoczi static void stream_set_speed(BlockJob *job, int64_t speed, Error **errp) 2025094a6c0SStefan Hajnoczi { 2035094a6c0SStefan Hajnoczi StreamBlockJob *s = container_of(job, StreamBlockJob, common); 2045094a6c0SStefan Hajnoczi 205882ec7ceSStefan Hajnoczi if (speed < 0) { 206c6bd8c70SMarkus Armbruster error_setg(errp, QERR_INVALID_PARAMETER, "speed"); 2079e6636c7SStefan Hajnoczi return; 2085094a6c0SStefan Hajnoczi } 2096ef228fcSPaolo Bonzini ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME); 2105094a6c0SStefan Hajnoczi } 2115094a6c0SStefan Hajnoczi 2123fc4b10aSFam Zheng static const BlockJobDriver stream_job_driver = { 2134f1043b4SStefan Hajnoczi .instance_size = sizeof(StreamBlockJob), 21479e14bf7SFam Zheng .job_type = BLOCK_JOB_TYPE_STREAM, 2155094a6c0SStefan Hajnoczi .set_speed = stream_set_speed, 2164f1043b4SStefan Hajnoczi }; 2174f1043b4SStefan Hajnoczi 218fd7f8c65SStefan Hajnoczi void stream_start(BlockDriverState *bs, BlockDriverState *base, 21913d8cc51SJeff Cody const char *backing_file_str, int64_t speed, 2201d809098SPaolo Bonzini BlockdevOnError on_error, 221097310b5SMarkus Armbruster BlockCompletionFunc *cb, 222fd7f8c65SStefan Hajnoczi void *opaque, Error **errp) 2234f1043b4SStefan Hajnoczi { 2244f1043b4SStefan Hajnoczi StreamBlockJob *s; 2254f1043b4SStefan Hajnoczi 2261d809098SPaolo Bonzini if ((on_error == BLOCKDEV_ON_ERROR_STOP || 2271d809098SPaolo Bonzini on_error == BLOCKDEV_ON_ERROR_ENOSPC) && 228373340b2SMax Reitz (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) { 229c6bd8c70SMarkus Armbruster error_setg(errp, QERR_INVALID_PARAMETER, "on-error"); 2301d809098SPaolo Bonzini return; 2311d809098SPaolo Bonzini } 2321d809098SPaolo Bonzini 2333fc4b10aSFam Zheng s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp); 2344f1043b4SStefan Hajnoczi if (!s) { 235fd7f8c65SStefan Hajnoczi return; 2364f1043b4SStefan Hajnoczi } 2374f1043b4SStefan Hajnoczi 2384f1043b4SStefan Hajnoczi s->base = base; 23913d8cc51SJeff Cody s->backing_file_str = g_strdup(backing_file_str); 2404f1043b4SStefan Hajnoczi 2411d809098SPaolo Bonzini s->on_error = on_error; 242fa4478d5SPaolo Bonzini s->common.co = qemu_coroutine_create(stream_run); 243fa4478d5SPaolo Bonzini trace_stream_start(bs, base, s, s->common.co, opaque); 244fa4478d5SPaolo Bonzini qemu_coroutine_enter(s->common.co, s); 2454f1043b4SStefan Hajnoczi } 246