qemu

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