cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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block-helpers.c (1378B)

      1/*
      2 * Block utility functions
      3 *
      4 * Copyright IBM, Corp. 2011
      5 * Copyright (c) 2020 Coiby Xu <coiby.xu@gmail.com>
      6 *
      7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
      8 * See the COPYING file in the top-level directory.
      9 */
     10
     11#include "qemu/osdep.h"
     12#include "qapi/error.h"
     13#include "qapi/qmp/qerror.h"
     14#include "block-helpers.h"
     15
     16/**
     17 * check_block_size:
     18 * @id: The unique ID of the object
     19 * @name: The name of the property being validated
     20 * @value: The block size in bytes
     21 * @errp: A pointer to an area to store an error
     22 *
     23 * This function checks that the block size meets the following conditions:
     24 * 1. At least MIN_BLOCK_SIZE
     25 * 2. No larger than MAX_BLOCK_SIZE
     26 * 3. A power of 2
     27 */
     28void check_block_size(const char *id, const char *name, int64_t value,
     29                      Error **errp)
     30{
     31    /* value of 0 means "unset" */
     32    if (value && (value < MIN_BLOCK_SIZE || value > MAX_BLOCK_SIZE)) {
     33        error_setg(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE,
     34                   id, name, value, MIN_BLOCK_SIZE, MAX_BLOCK_SIZE);
     35        return;
     36    }
     37
     38    /* We rely on power-of-2 blocksizes for bitmasks */
     39    if ((value & (value - 1)) != 0) {
     40        error_setg(errp,
     41                   "Property %s.%s doesn't take value '%" PRId64
     42                   "', it's not a power of 2",
     43                   id, name, value);
     44        return;
     45    }
     46}