diff options
Diffstat (limited to 'hw/block/block.c')
| -rw-r--r-- | hw/block/block.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/hw/block/block.c b/hw/block/block.c new file mode 100644 index 000000000..d47ebf005 --- /dev/null +++ b/hw/block/block.c @@ -0,0 +1,238 @@ +/* + * 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 "sysemu/blockdev.h" +#include "sysemu/block-backend.h" +#include "hw/block/block.h" +#include "qapi/error.h" +#include "qapi/qapi-types-block.h" + +/* + * 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. + * Note that the error messages do not identify the block backend. + * TODO Since callers don't either, this can result in confusing + * errors. + * 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, void *buf, hwaddr size, + Error **errp) +{ + int64_t blk_len; + int ret; + + blk_len = blk_getlength(blk); + if (blk_len < 0) { + error_setg_errno(errp, -blk_len, + "can't get size of block backend"); + return false; + } + if (blk_len != size) { + error_setg(errp, "device requires %" HWADDR_PRIu " bytes, " + "block backend provides %" PRIu64 " bytes", + size, 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(blk, 0, buf, size); + if (ret < 0) { + error_setg_errno(errp, -ret, "can't read block backend"); + 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; +} + +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 | + BLK_PERM_GRAPH_MOD; + 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); + + 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; +} |