| /* | |
| * Common code for block device models | |
| * | |
| * Copyright (C) 2012 Red Hat, Inc. | |
| * | |
| * This work is licensed under the terms of the GNU GPL, version 2 or | |
| * later. See the COPYING file in the top-level directory. | |
| */ | |
| #include "qemu/osdep.h" | |
| #include "block/block_int-common.h" | |
| #include "system/blockdev.h" | |
| #include "system/block-backend.h" | |
| #include "hw/block/block.h" | |
| #include "migration/cpr.h" | |
| #include "qapi/error.h" | |
| #include "qapi/qapi-types-block.h" | |
| /* | |
| * Read the non-zeroes parts of @blk into @buf | |
| * Reading all of the @blk is expensive if the zeroes parts of @blk | |
| * is large enough. Therefore check the block status and only write | |
| * the non-zeroes block into @buf. | |
| * | |
| * Return 0 on success, non-zero on error. | |
| */ | |
| static int blk_pread_nonzeroes(BlockBackend *blk, hwaddr size, void *buf) | |
| { | |
| int ret; | |
| int64_t bytes, offset = 0; | |
| BlockDriverState *bs = blk_bs(blk); | |
| for (;;) { | |
| bytes = MIN(size - offset, BDRV_REQUEST_MAX_BYTES); | |
| if (bytes <= 0) { | |
| return 0; | |
| } | |
| ret = bdrv_block_status(bs, offset, bytes, &bytes, NULL, NULL); | |
| if (ret < 0) { | |
| return ret; | |
| } | |
| if (!(ret & BDRV_BLOCK_ZERO)) { | |
| ret = blk_pread(blk, offset, bytes, (uint8_t *) buf + offset, 0); | |
| if (ret < 0) { | |
| return ret; | |
| } | |
| } | |
| offset += bytes; | |
| } | |
| } | |
| /* | |
| * Read the entire contents of @blk into @buf. | |
| * @blk's contents must be @size bytes, and @size must be at most | |
| * BDRV_REQUEST_MAX_BYTES. | |
| * On success, return true. | |
| * On failure, store an error through @errp and return false. | |
| * | |
| * This function not intended for actual block devices, which read on | |
| * demand. It's for things like memory devices that (ab)use a block | |
| * backend to provide persistence. | |
| */ | |
| bool blk_check_size_and_read_all(BlockBackend *blk, DeviceState *dev, | |
| void *buf, hwaddr size, Error **errp) | |
| { | |
| int64_t blk_len; | |
| int ret; | |
| g_autofree char *dev_id = NULL; | |
| if (cpr_is_incoming()) { | |
| return true; | |
| } | |
| blk_len = blk_getlength(blk); | |
| if (blk_len < 0) { | |
| error_setg_errno(errp, -blk_len, | |
| "can't get size of %s block backend", blk_name(blk)); | |
| return false; | |
| } | |
| if (blk_len != size) { | |
| dev_id = qdev_get_human_name(dev); | |
| error_setg(errp, "%s device '%s' requires %" HWADDR_PRIu | |
| " bytes, %s block backend provides %" PRIu64 " bytes", | |
| object_get_typename(OBJECT(dev)), dev_id, size, | |
| blk_name(blk), blk_len); | |
| return false; | |
| } | |
| /* | |
| * We could loop for @size > BDRV_REQUEST_MAX_BYTES, but if we | |
| * ever get to the point we want to read *gigabytes* here, we | |
| * should probably rework the device to be more like an actual | |
| * block device and read only on demand. | |
| */ | |
| assert(size <= BDRV_REQUEST_MAX_BYTES); | |
| ret = blk_pread_nonzeroes(blk, size, buf); | |
| if (ret < 0) { | |
| dev_id = qdev_get_human_name(dev); | |
| error_setg_errno(errp, -ret, "can't read %s block backend" | |
| " for %s device '%s'", | |
| blk_name(blk), object_get_typename(OBJECT(dev)), | |
| dev_id); | |
| return false; | |
| } | |
| return true; | |
| } | |
| bool blkconf_blocksizes(BlockConf *conf, Error **errp) | |
| { | |
| BlockBackend *blk = conf->blk; | |
| BlockSizes blocksizes; | |
| BlockDriverState *bs; | |
| bool use_blocksizes; | |
| bool use_bs; | |
| switch (conf->backend_defaults) { | |
| case ON_OFF_AUTO_AUTO: | |
| use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes); | |
| use_bs = false; | |
| break; | |
| case ON_OFF_AUTO_ON: | |
| use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes); | |
| bs = blk_bs(blk); | |
| use_bs = bs; | |
| break; | |
| case ON_OFF_AUTO_OFF: | |
| use_blocksizes = false; | |
| use_bs = false; | |
| break; | |
| default: | |
| abort(); | |
| } | |
| /* fill in detected values if they are not defined via qemu command line */ | |
| if (!conf->physical_block_size) { | |
| if (use_blocksizes) { | |
| conf->physical_block_size = blocksizes.phys; | |
| } else { | |
| conf->physical_block_size = BDRV_SECTOR_SIZE; | |
| } | |
| } | |
| if (!conf->logical_block_size) { | |
| if (use_blocksizes) { | |
| conf->logical_block_size = blocksizes.log; | |
| } else { | |
| conf->logical_block_size = BDRV_SECTOR_SIZE; | |
| } | |
| } | |
| if (use_bs) { | |
| if (!conf->opt_io_size) { | |
| conf->opt_io_size = bs->bl.opt_transfer; | |
| } | |
| if (conf->discard_granularity == -1) { | |
| if (bs->bl.pdiscard_alignment) { | |
| conf->discard_granularity = bs->bl.pdiscard_alignment; | |
| } else if (bs->bl.request_alignment != 1) { | |
| conf->discard_granularity = bs->bl.request_alignment; | |
| } | |
| } | |
| } | |
| if (conf->logical_block_size > conf->physical_block_size) { | |
| error_setg(errp, | |
| "logical_block_size > physical_block_size not supported"); | |
| return false; | |
| } | |
| if (!QEMU_IS_ALIGNED(conf->min_io_size, conf->logical_block_size)) { | |
| error_setg(errp, | |
| "min_io_size must be a multiple of logical_block_size"); | |
| return false; | |
| } | |
| /* | |
| * all devices which support min_io_size (scsi and virtio-blk) expose it to | |
| * the guest as a uint16_t in units of logical blocks | |
| */ | |
| if (conf->min_io_size / conf->logical_block_size > UINT16_MAX) { | |
| error_setg(errp, "min_io_size must not exceed %u logical blocks", | |
| UINT16_MAX); | |
| return false; | |
| } | |
| if (!QEMU_IS_ALIGNED(conf->opt_io_size, conf->logical_block_size)) { | |
| error_setg(errp, | |
| "opt_io_size must be a multiple of logical_block_size"); | |
| return false; | |
| } | |
| if (conf->discard_granularity != -1 && | |
| !QEMU_IS_ALIGNED(conf->discard_granularity, | |
| conf->logical_block_size)) { | |
| error_setg(errp, "discard_granularity must be " | |
| "a multiple of logical_block_size"); | |
| return false; | |
| } | |
| return true; | |
| } | |
| uint32_t blkconf_zone_write_granularity(BlockConf *conf) | |
| { | |
| return MAX(conf->logical_block_size, conf->physical_block_size); | |
| } | |
| bool blkconf_check_zoned_geometry(BlockConf *conf, Error **errp) | |
| { | |
| BlockDriverState *bs = blk_bs(conf->blk); | |
| uint32_t wg; | |
| if (bs->bl.zoned == BLK_Z_NONE) { | |
| return true; | |
| } | |
| wg = blkconf_zone_write_granularity(conf); | |
| /* | |
| * A backend that requires a coarser granularity than the one that is about | |
| * to be reported would reject writes that the guest has been told are | |
| * valid, leaving it with a plain I/O error. | |
| */ | |
| if (bs->bl.write_granularity > wg) { | |
| error_setg(errp, "the backend requires writes to sequential zones to " | |
| "be a multiple of %" PRIu32 " bytes, which is coarser than " | |
| "the zone write granularity %" PRIu32 " that would be " | |
| "reported", bs->bl.write_granularity, wg); | |
| error_append_hint(errp, "Set physical_block_size=%" PRIu32 ".\n", | |
| bs->bl.write_granularity); | |
| return false; | |
| } | |
| if (!QEMU_IS_ALIGNED(bs->bl.zone_size, wg)) { | |
| error_setg(errp, "zone size %" PRIu64 " is not a multiple of the zone " | |
| "write granularity %" PRIu32, bs->bl.zone_size, wg); | |
| return false; | |
| } | |
| /* | |
| * A write pointer that is not a multiple of the write granularity does not | |
| * fall on a logical block boundary, so the guest can neither read nor write | |
| * at it and the zone can only be recovered by resetting it. A backend that | |
| * records its write pointers, rather than reading them back from a device, | |
| * can hand us such a pointer when the zones were written while the device | |
| * was configured with a smaller logical block size. | |
| */ | |
| for (uint32_t i = 0; i < bs->bl.nr_zones; i++) { | |
| uint64_t wp; | |
| if (bdrv_zone_is_conv(bs, i)) { | |
| continue; | |
| } | |
| wp = bs->wps->wp[i]; | |
| if (!QEMU_IS_ALIGNED(wp, wg)) { | |
| error_setg(errp, "write pointer 0x%" PRIx64 " of zone %" PRIu32 | |
| " is not a multiple of the zone write granularity %" | |
| PRIu32, wp, i, wg); | |
| error_append_hint(errp, "The zones were written with a finer zone " | |
| "write granularity. Reset them, or attach the " | |
| "device with the block sizes that they were " | |
| "written with.\n"); | |
| return false; | |
| } | |
| } | |
| return true; | |
| } | |
| bool blkconf_apply_backend_options(BlockConf *conf, bool readonly, | |
| bool resizable, Error **errp) | |
| { | |
| BlockBackend *blk = conf->blk; | |
| BlockdevOnError rerror, werror; | |
| uint64_t perm, shared_perm; | |
| bool wce; | |
| int ret; | |
| perm = BLK_PERM_CONSISTENT_READ; | |
| if (!readonly) { | |
| perm |= BLK_PERM_WRITE; | |
| } | |
| shared_perm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED; | |
| if (resizable) { | |
| shared_perm |= BLK_PERM_RESIZE; | |
| } | |
| if (conf->share_rw) { | |
| shared_perm |= BLK_PERM_WRITE; | |
| } | |
| ret = blk_set_perm(blk, perm, shared_perm, errp); | |
| if (ret < 0) { | |
| return false; | |
| } | |
| switch (conf->wce) { | |
| case ON_OFF_AUTO_ON: wce = true; break; | |
| case ON_OFF_AUTO_OFF: wce = false; break; | |
| case ON_OFF_AUTO_AUTO: wce = blk_enable_write_cache(blk); break; | |
| default: | |
| abort(); | |
| } | |
| rerror = conf->rerror; | |
| if (rerror == BLOCKDEV_ON_ERROR_AUTO) { | |
| rerror = blk_get_on_error(blk, true); | |
| } | |
| werror = conf->werror; | |
| if (werror == BLOCKDEV_ON_ERROR_AUTO) { | |
| werror = blk_get_on_error(blk, false); | |
| } | |
| blk_set_enable_write_cache(blk, wce); | |
| blk_set_on_error(blk, rerror, werror); | |
| if (!block_acct_setup(blk_get_stats(blk), conf->account_invalid, | |
| conf->account_failed, conf->stats_intervals, | |
| conf->num_stats_intervals, errp)) { | |
| return false; | |
| } | |
| return true; | |
| } | |
| bool blkconf_geometry(BlockConf *conf, int *ptrans, | |
| unsigned cyls_max, unsigned heads_max, unsigned secs_max, | |
| Error **errp) | |
| { | |
| if (!conf->cyls && !conf->heads && !conf->secs) { | |
| hd_geometry_guess(conf->blk, | |
| &conf->cyls, &conf->heads, &conf->secs, | |
| ptrans); | |
| } else if (ptrans && *ptrans == BIOS_ATA_TRANSLATION_AUTO) { | |
| *ptrans = hd_bios_chs_auto_trans(conf->cyls, conf->heads, conf->secs); | |
| } | |
| if (conf->cyls || conf->heads || conf->secs) { | |
| if (conf->cyls < 1 || conf->cyls > cyls_max) { | |
| error_setg(errp, "cyls must be between 1 and %u", cyls_max); | |
| return false; | |
| } | |
| if (conf->heads < 1 || conf->heads > heads_max) { | |
| error_setg(errp, "heads must be between 1 and %u", heads_max); | |
| return false; | |
| } | |
| if (conf->secs < 1 || conf->secs > secs_max) { | |
| error_setg(errp, "secs must be between 1 and %u", secs_max); | |
| return false; | |
| } | |
| } | |
| return true; | |
| } |