diff options
| -rw-r--r-- | hw/block/block.c | 48 | ||||
| -rw-r--r-- | hw/block/pflash_cfi01.c | 8 | ||||
| -rw-r--r-- | hw/block/pflash_cfi02.c | 7 | ||||
| -rw-r--r-- | include/hw/block/block.h | 7 |
4 files changed, 59 insertions, 11 deletions
diff --git a/hw/block/block.c b/hw/block/block.c index cf0eb82..bf56c76 100644 --- a/hw/block/block.c +++ b/hw/block/block.c @@ -13,7 +13,53 @@ #include "hw/block/block.h" #include "qapi/error.h" #include "qapi/qapi-types-block.h" -#include "qemu/error-report.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; +} void blkconf_blocksizes(BlockConf *conf) { diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c index 125f70b..9937739 100644 --- a/hw/block/pflash_cfi01.c +++ b/hw/block/pflash_cfi01.c @@ -38,6 +38,7 @@ #include "qemu/osdep.h" #include "hw/hw.h" +#include "hw/block/block.h" #include "hw/block/flash.h" #include "sysemu/block-backend.h" #include "qapi/error.h" @@ -763,12 +764,9 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp) } if (pfl->blk) { - /* read the initial flash content */ - ret = blk_pread(pfl->blk, 0, pfl->storage, total_len); - - if (ret < 0) { + if (!blk_check_size_and_read_all(pfl->blk, pfl->storage, total_len, + errp)) { vmstate_unregister_ram(&pfl->mem, DEVICE(pfl)); - error_setg(errp, "failed to read the initial flash content"); return; } } diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c index c9db430..9b93430 100644 --- a/hw/block/pflash_cfi02.c +++ b/hw/block/pflash_cfi02.c @@ -37,6 +37,7 @@ #include "qemu/osdep.h" #include "hw/hw.h" +#include "hw/block/block.h" #include "hw/block/flash.h" #include "qapi/error.h" #include "qemu/timer.h" @@ -581,11 +582,9 @@ static void pflash_cfi02_realize(DeviceState *dev, Error **errp) } if (pfl->blk) { - /* read the initial flash content */ - ret = blk_pread(pfl->blk, 0, pfl->storage, chip_len); - if (ret < 0) { + if (!blk_check_size_and_read_all(pfl->blk, pfl->storage, chip_len, + errp)) { vmstate_unregister_ram(&pfl->orig_mem, DEVICE(pfl)); - error_setg(errp, "failed to read the initial flash content"); return; } } diff --git a/include/hw/block/block.h b/include/hw/block/block.h index e9f9e22..d06f25a 100644 --- a/include/hw/block/block.h +++ b/include/hw/block/block.h @@ -11,7 +11,7 @@ #ifndef HW_BLOCK_H #define HW_BLOCK_H -#include "qemu-common.h" +#include "exec/hwaddr.h" #include "qapi/qapi-types-block-core.h" /* Configuration */ @@ -70,6 +70,11 @@ static inline unsigned int get_physical_block_exp(BlockConf *conf) DEFINE_PROP_BLOCKDEV_ON_ERROR("werror", _state, _conf.werror, \ BLOCKDEV_ON_ERROR_AUTO) +/* Backend access helpers */ + +bool blk_check_size_and_read_all(BlockBackend *blk, void *buf, hwaddr size, + Error **errp); + /* Configuration helpers */ bool blkconf_geometry(BlockConf *conf, int *trans, |