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 */ 28 void 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 }