/* * QEMU System Emulator block write threshold notification * * Copyright Red Hat, Inc. 2014 * * Authors: * Francesco Romani <fromani@redhat.com> * * This work is licensed under the terms of the GNU LGPL, version 2 or later. * See the COPYING.LIB file in the top-level directory. */ #include "qemu/osdep.h" #include "block/block-io.h" #include "block/block_int.h" #include "block/write-threshold.h" #include "qapi/error.h" #include "qapi/qapi-commands-block-core.h" #include "qapi/qapi-events-block-core.h" uint64_t bdrv_write_threshold_get(const BlockDriverState *bs) { return bs->write_threshold_offset; } void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes) { bs->write_threshold_offset = threshold_bytes; } void qmp_block_set_write_threshold(const char *node_name, uint64_t threshold_bytes, Error **errp) { BlockDriverState *bs; AioContext *aio_context; bs = bdrv_find_node(node_name); if (!bs) { error_setg(errp, "Device '%s' not found", node_name); return; } aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); bdrv_write_threshold_set(bs, threshold_bytes); aio_context_release(aio_context); } void bdrv_write_threshold_check_write(BlockDriverState *bs, int64_t offset, int64_t bytes) { int64_t end = offset + bytes; uint64_t wtr = bs->write_threshold_offset; if (wtr > 0 && end > wtr) { qapi_event_send_block_write_threshold(bs->node_name, end - wtr, wtr); /* autodisable to avoid flooding the monitor */ bdrv_write_threshold_set(bs, 0); } }