 bfb197e0d9
			
		
	
	
		bfb197e0d9
		
	
	
	
	
		
			
			device_name[] can become non-empty only in bdrv_new_root() and bdrv_move_feature_fields(). The latter is used only to undo damage done by bdrv_swap(). The former is called only by blk_new_with_bs(). Therefore, when a BlockDriverState's device_name[] is non-empty, then it's been created with a BlockBackend, and vice versa. Furthermore, blk_new_with_bs() keeps the two names equal. Therefore, device_name[] is redundant. Eliminate it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
		
			
				
	
	
		
			930 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			930 lines
		
	
	
		
			26 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Block driver for Connectix / Microsoft Virtual PC images
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|  *
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|  * Copyright (c) 2005 Alex Beregszaszi
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|  * Copyright (c) 2009 Kevin Wolf <kwolf@suse.de>
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a copy
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|  * of this software and associated documentation files (the "Software"), to deal
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|  * in the Software without restriction, including without limitation the rights
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|  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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|  * copies of the Software, and to permit persons to whom the Software is
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|  * furnished to do so, subject to the following conditions:
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|  *
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|  * The above copyright notice and this permission notice shall be included in
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|  * all copies or substantial portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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|  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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|  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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|  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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|  * THE SOFTWARE.
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|  */
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| #include "qemu-common.h"
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| #include "block/block_int.h"
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| #include "qemu/module.h"
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| #include "migration/migration.h"
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| #if defined(CONFIG_UUID)
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| #include <uuid/uuid.h>
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| #endif
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| 
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| /**************************************************************/
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| 
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| #define HEADER_SIZE 512
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| 
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| //#define CACHE
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| 
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| enum vhd_type {
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|     VHD_FIXED           = 2,
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|     VHD_DYNAMIC         = 3,
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|     VHD_DIFFERENCING    = 4,
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| };
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| 
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| // Seconds since Jan 1, 2000 0:00:00 (UTC)
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| #define VHD_TIMESTAMP_BASE 946684800
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| 
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| #define VHD_MAX_SECTORS       (65535LL * 255 * 255)
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| 
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| // always big-endian
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| typedef struct vhd_footer {
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|     char        creator[8]; // "conectix"
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|     uint32_t    features;
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|     uint32_t    version;
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| 
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|     // Offset of next header structure, 0xFFFFFFFF if none
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|     uint64_t    data_offset;
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| 
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|     // Seconds since Jan 1, 2000 0:00:00 (UTC)
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|     uint32_t    timestamp;
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| 
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|     char        creator_app[4]; // "vpc "
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|     uint16_t    major;
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|     uint16_t    minor;
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|     char        creator_os[4]; // "Wi2k"
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| 
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|     uint64_t    orig_size;
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|     uint64_t    size;
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| 
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|     uint16_t    cyls;
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|     uint8_t     heads;
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|     uint8_t     secs_per_cyl;
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| 
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|     uint32_t    type;
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| 
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|     // Checksum of the Hard Disk Footer ("one's complement of the sum of all
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|     // the bytes in the footer without the checksum field")
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|     uint32_t    checksum;
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| 
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|     // UUID used to identify a parent hard disk (backing file)
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|     uint8_t     uuid[16];
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| 
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|     uint8_t     in_saved_state;
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| } QEMU_PACKED VHDFooter;
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| 
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| typedef struct vhd_dyndisk_header {
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|     char        magic[8]; // "cxsparse"
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| 
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|     // Offset of next header structure, 0xFFFFFFFF if none
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|     uint64_t    data_offset;
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| 
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|     // Offset of the Block Allocation Table (BAT)
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|     uint64_t    table_offset;
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| 
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|     uint32_t    version;
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|     uint32_t    max_table_entries; // 32bit/entry
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| 
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|     // 2 MB by default, must be a power of two
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|     uint32_t    block_size;
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| 
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|     uint32_t    checksum;
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|     uint8_t     parent_uuid[16];
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|     uint32_t    parent_timestamp;
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|     uint32_t    reserved;
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| 
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|     // Backing file name (in UTF-16)
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|     uint8_t     parent_name[512];
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| 
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|     struct {
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|         uint32_t    platform;
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|         uint32_t    data_space;
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|         uint32_t    data_length;
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|         uint32_t    reserved;
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|         uint64_t    data_offset;
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|     } parent_locator[8];
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| } QEMU_PACKED VHDDynDiskHeader;
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| 
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| typedef struct BDRVVPCState {
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|     CoMutex lock;
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|     uint8_t footer_buf[HEADER_SIZE];
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|     uint64_t free_data_block_offset;
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|     int max_table_entries;
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|     uint32_t *pagetable;
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|     uint64_t bat_offset;
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|     uint64_t last_bitmap_offset;
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| 
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|     uint32_t block_size;
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|     uint32_t bitmap_size;
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| 
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| #ifdef CACHE
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|     uint8_t *pageentry_u8;
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|     uint32_t *pageentry_u32;
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|     uint16_t *pageentry_u16;
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| 
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|     uint64_t last_bitmap;
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| #endif
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| 
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|     Error *migration_blocker;
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| } BDRVVPCState;
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| 
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| static uint32_t vpc_checksum(uint8_t* buf, size_t size)
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| {
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|     uint32_t res = 0;
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|     int i;
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| 
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|     for (i = 0; i < size; i++)
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|         res += buf[i];
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| 
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|     return ~res;
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| }
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| 
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| 
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| static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
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| {
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|     if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8))
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| 	return 100;
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|     return 0;
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| }
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| 
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| static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
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|                     Error **errp)
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| {
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|     BDRVVPCState *s = bs->opaque;
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|     int i;
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|     VHDFooter *footer;
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|     VHDDynDiskHeader *dyndisk_header;
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|     uint8_t buf[HEADER_SIZE];
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|     uint32_t checksum;
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|     uint64_t computed_size;
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|     int disk_type = VHD_DYNAMIC;
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|     int ret;
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| 
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|     ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE);
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|     if (ret < 0) {
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|         goto fail;
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|     }
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| 
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|     footer = (VHDFooter *) s->footer_buf;
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|     if (strncmp(footer->creator, "conectix", 8)) {
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|         int64_t offset = bdrv_getlength(bs->file);
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|         if (offset < 0) {
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|             ret = offset;
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|             goto fail;
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|         } else if (offset < HEADER_SIZE) {
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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| 
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|         /* If a fixed disk, the footer is found only at the end of the file */
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|         ret = bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf,
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|                          HEADER_SIZE);
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|         if (ret < 0) {
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|             goto fail;
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|         }
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|         if (strncmp(footer->creator, "conectix", 8)) {
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|             error_setg(errp, "invalid VPC image");
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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|         disk_type = VHD_FIXED;
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|     }
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| 
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|     checksum = be32_to_cpu(footer->checksum);
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|     footer->checksum = 0;
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|     if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum)
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|         fprintf(stderr, "block-vpc: The header checksum of '%s' is "
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|             "incorrect.\n", bs->filename);
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| 
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|     /* Write 'checksum' back to footer, or else will leave it with zero. */
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|     footer->checksum = cpu_to_be32(checksum);
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| 
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|     // The visible size of a image in Virtual PC depends on the geometry
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|     // rather than on the size stored in the footer (the size in the footer
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|     // is too large usually)
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|     bs->total_sectors = (int64_t)
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|         be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
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| 
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|     /* images created with disk2vhd report a far higher virtual size
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|      * than expected with the cyls * heads * sectors_per_cyl formula.
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|      * use the footer->size instead if the image was created with
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|      * disk2vhd.
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|      */
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|     if (!strncmp(footer->creator_app, "d2v", 4)) {
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|         bs->total_sectors = be64_to_cpu(footer->size) / BDRV_SECTOR_SIZE;
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|     }
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| 
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|     /* Allow a maximum disk size of approximately 2 TB */
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|     if (bs->total_sectors >= VHD_MAX_SECTORS) {
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|         ret = -EFBIG;
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|         goto fail;
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|     }
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| 
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|     if (disk_type == VHD_DYNAMIC) {
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|         ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf,
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|                          HEADER_SIZE);
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|         if (ret < 0) {
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|             goto fail;
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|         }
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| 
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|         dyndisk_header = (VHDDynDiskHeader *) buf;
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| 
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|         if (strncmp(dyndisk_header->magic, "cxsparse", 8)) {
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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| 
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|         s->block_size = be32_to_cpu(dyndisk_header->block_size);
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|         if (!is_power_of_2(s->block_size) || s->block_size < BDRV_SECTOR_SIZE) {
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|             error_setg(errp, "Invalid block size %" PRIu32, s->block_size);
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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|         s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511;
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| 
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|         s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
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| 
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|         if ((bs->total_sectors * 512) / s->block_size > 0xffffffffU) {
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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|         if (s->max_table_entries > (VHD_MAX_SECTORS * 512) / s->block_size) {
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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| 
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|         computed_size = (uint64_t) s->max_table_entries * s->block_size;
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|         if (computed_size < bs->total_sectors * 512) {
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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| 
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|         s->pagetable = qemu_try_blockalign(bs->file, s->max_table_entries * 4);
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|         if (s->pagetable == NULL) {
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|             ret = -ENOMEM;
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|             goto fail;
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|         }
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| 
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|         s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
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| 
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|         ret = bdrv_pread(bs->file, s->bat_offset, s->pagetable,
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|                          s->max_table_entries * 4);
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|         if (ret < 0) {
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|             goto fail;
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|         }
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| 
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|         s->free_data_block_offset =
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|             (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511;
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| 
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|         for (i = 0; i < s->max_table_entries; i++) {
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|             be32_to_cpus(&s->pagetable[i]);
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|             if (s->pagetable[i] != 0xFFFFFFFF) {
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|                 int64_t next = (512 * (int64_t) s->pagetable[i]) +
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|                     s->bitmap_size + s->block_size;
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| 
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|                 if (next > s->free_data_block_offset) {
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|                     s->free_data_block_offset = next;
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|                 }
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|             }
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|         }
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| 
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|         if (s->free_data_block_offset > bdrv_getlength(bs->file)) {
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|             error_setg(errp, "block-vpc: free_data_block_offset points after "
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|                              "the end of file. The image has been truncated.");
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|             ret = -EINVAL;
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|             goto fail;
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|         }
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| 
 | |
|         s->last_bitmap_offset = (int64_t) -1;
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| 
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| #ifdef CACHE
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|         s->pageentry_u8 = g_malloc(512);
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|         s->pageentry_u32 = s->pageentry_u8;
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|         s->pageentry_u16 = s->pageentry_u8;
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|         s->last_pagetable = -1;
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| #endif
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|     }
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| 
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|     qemu_co_mutex_init(&s->lock);
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| 
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|     /* Disable migration when VHD images are used */
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|     error_set(&s->migration_blocker,
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|               QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
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|               "vpc", bdrv_get_device_name(bs), "live migration");
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|     migrate_add_blocker(s->migration_blocker);
 | |
| 
 | |
|     return 0;
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| 
 | |
| fail:
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|     qemu_vfree(s->pagetable);
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| #ifdef CACHE
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|     g_free(s->pageentry_u8);
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| #endif
 | |
|     return ret;
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| }
 | |
| 
 | |
| static int vpc_reopen_prepare(BDRVReopenState *state,
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|                               BlockReopenQueue *queue, Error **errp)
 | |
| {
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|     return 0;
 | |
| }
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| 
 | |
| /*
 | |
|  * Returns the absolute byte offset of the given sector in the image file.
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|  * If the sector is not allocated, -1 is returned instead.
 | |
|  *
 | |
|  * The parameter write must be 1 if the offset will be used for a write
 | |
|  * operation (the block bitmaps is updated then), 0 otherwise.
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|  */
 | |
| static inline int64_t get_sector_offset(BlockDriverState *bs,
 | |
|     int64_t sector_num, int write)
 | |
| {
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     uint64_t offset = sector_num * 512;
 | |
|     uint64_t bitmap_offset, block_offset;
 | |
|     uint32_t pagetable_index, pageentry_index;
 | |
| 
 | |
|     pagetable_index = offset / s->block_size;
 | |
|     pageentry_index = (offset % s->block_size) / 512;
 | |
| 
 | |
|     if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff)
 | |
|         return -1; // not allocated
 | |
| 
 | |
|     bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index];
 | |
|     block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index);
 | |
| 
 | |
|     // We must ensure that we don't write to any sectors which are marked as
 | |
|     // unused in the bitmap. We get away with setting all bits in the block
 | |
|     // bitmap each time we write to a new block. This might cause Virtual PC to
 | |
|     // miss sparse read optimization, but it's not a problem in terms of
 | |
|     // correctness.
 | |
|     if (write && (s->last_bitmap_offset != bitmap_offset)) {
 | |
|         uint8_t bitmap[s->bitmap_size];
 | |
| 
 | |
|         s->last_bitmap_offset = bitmap_offset;
 | |
|         memset(bitmap, 0xff, s->bitmap_size);
 | |
|         bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size);
 | |
|     }
 | |
| 
 | |
| //    printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",
 | |
| //	sector_num, pagetable_index, pageentry_index,
 | |
| //	bitmap_offset, block_offset);
 | |
| 
 | |
| // disabled by reason
 | |
| #if 0
 | |
| #ifdef CACHE
 | |
|     if (bitmap_offset != s->last_bitmap)
 | |
|     {
 | |
| 	lseek(s->fd, bitmap_offset, SEEK_SET);
 | |
| 
 | |
| 	s->last_bitmap = bitmap_offset;
 | |
| 
 | |
| 	// Scary! Bitmap is stored as big endian 32bit entries,
 | |
| 	// while we used to look it up byte by byte
 | |
| 	read(s->fd, s->pageentry_u8, 512);
 | |
| 	for (i = 0; i < 128; i++)
 | |
| 	    be32_to_cpus(&s->pageentry_u32[i]);
 | |
|     }
 | |
| 
 | |
|     if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1)
 | |
| 	return -1;
 | |
| #else
 | |
|     lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET);
 | |
| 
 | |
|     read(s->fd, &bitmap_entry, 1);
 | |
| 
 | |
|     if ((bitmap_entry >> (pageentry_index % 8)) & 1)
 | |
| 	return -1; // not allocated
 | |
| #endif
 | |
| #endif
 | |
| 
 | |
|     return block_offset;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Writes the footer to the end of the image file. This is needed when the
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|  * file grows as it overwrites the old footer
 | |
|  *
 | |
|  * Returns 0 on success and < 0 on error
 | |
|  */
 | |
| static int rewrite_footer(BlockDriverState* bs)
 | |
| {
 | |
|     int ret;
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     int64_t offset = s->free_data_block_offset;
 | |
| 
 | |
|     ret = bdrv_pwrite_sync(bs->file, offset, s->footer_buf, HEADER_SIZE);
 | |
|     if (ret < 0)
 | |
|         return ret;
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Allocates a new block. This involves writing a new footer and updating
 | |
|  * the Block Allocation Table to use the space at the old end of the image
 | |
|  * file (overwriting the old footer)
 | |
|  *
 | |
|  * Returns the sectors' offset in the image file on success and < 0 on error
 | |
|  */
 | |
| static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
 | |
| {
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     int64_t bat_offset;
 | |
|     uint32_t index, bat_value;
 | |
|     int ret;
 | |
|     uint8_t bitmap[s->bitmap_size];
 | |
| 
 | |
|     // Check if sector_num is valid
 | |
|     if ((sector_num < 0) || (sector_num > bs->total_sectors))
 | |
|         return -1;
 | |
| 
 | |
|     // Write entry into in-memory BAT
 | |
|     index = (sector_num * 512) / s->block_size;
 | |
|     if (s->pagetable[index] != 0xFFFFFFFF)
 | |
|         return -1;
 | |
| 
 | |
|     s->pagetable[index] = s->free_data_block_offset / 512;
 | |
| 
 | |
|     // Initialize the block's bitmap
 | |
|     memset(bitmap, 0xff, s->bitmap_size);
 | |
|     ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap,
 | |
|         s->bitmap_size);
 | |
|     if (ret < 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     // Write new footer (the old one will be overwritten)
 | |
|     s->free_data_block_offset += s->block_size + s->bitmap_size;
 | |
|     ret = rewrite_footer(bs);
 | |
|     if (ret < 0)
 | |
|         goto fail;
 | |
| 
 | |
|     // Write BAT entry to disk
 | |
|     bat_offset = s->bat_offset + (4 * index);
 | |
|     bat_value = cpu_to_be32(s->pagetable[index]);
 | |
|     ret = bdrv_pwrite_sync(bs->file, bat_offset, &bat_value, 4);
 | |
|     if (ret < 0)
 | |
|         goto fail;
 | |
| 
 | |
|     return get_sector_offset(bs, sector_num, 0);
 | |
| 
 | |
| fail:
 | |
|     s->free_data_block_offset -= (s->block_size + s->bitmap_size);
 | |
|     return -1;
 | |
| }
 | |
| 
 | |
| static int vpc_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 | |
| {
 | |
|     BDRVVPCState *s = (BDRVVPCState *)bs->opaque;
 | |
|     VHDFooter *footer = (VHDFooter *) s->footer_buf;
 | |
| 
 | |
|     if (be32_to_cpu(footer->type) != VHD_FIXED) {
 | |
|         bdi->cluster_size = s->block_size;
 | |
|     }
 | |
| 
 | |
|     bdi->unallocated_blocks_are_zero = true;
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static int vpc_read(BlockDriverState *bs, int64_t sector_num,
 | |
|                     uint8_t *buf, int nb_sectors)
 | |
| {
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     int ret;
 | |
|     int64_t offset;
 | |
|     int64_t sectors, sectors_per_block;
 | |
|     VHDFooter *footer = (VHDFooter *) s->footer_buf;
 | |
| 
 | |
|     if (be32_to_cpu(footer->type) == VHD_FIXED) {
 | |
|         return bdrv_read(bs->file, sector_num, buf, nb_sectors);
 | |
|     }
 | |
|     while (nb_sectors > 0) {
 | |
|         offset = get_sector_offset(bs, sector_num, 0);
 | |
| 
 | |
|         sectors_per_block = s->block_size >> BDRV_SECTOR_BITS;
 | |
|         sectors = sectors_per_block - (sector_num % sectors_per_block);
 | |
|         if (sectors > nb_sectors) {
 | |
|             sectors = nb_sectors;
 | |
|         }
 | |
| 
 | |
|         if (offset == -1) {
 | |
|             memset(buf, 0, sectors * BDRV_SECTOR_SIZE);
 | |
|         } else {
 | |
|             ret = bdrv_pread(bs->file, offset, buf,
 | |
|                 sectors * BDRV_SECTOR_SIZE);
 | |
|             if (ret != sectors * BDRV_SECTOR_SIZE) {
 | |
|                 return -1;
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         nb_sectors -= sectors;
 | |
|         sector_num += sectors;
 | |
|         buf += sectors * BDRV_SECTOR_SIZE;
 | |
|     }
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static coroutine_fn int vpc_co_read(BlockDriverState *bs, int64_t sector_num,
 | |
|                                     uint8_t *buf, int nb_sectors)
 | |
| {
 | |
|     int ret;
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     qemu_co_mutex_lock(&s->lock);
 | |
|     ret = vpc_read(bs, sector_num, buf, nb_sectors);
 | |
|     qemu_co_mutex_unlock(&s->lock);
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static int vpc_write(BlockDriverState *bs, int64_t sector_num,
 | |
|     const uint8_t *buf, int nb_sectors)
 | |
| {
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     int64_t offset;
 | |
|     int64_t sectors, sectors_per_block;
 | |
|     int ret;
 | |
|     VHDFooter *footer =  (VHDFooter *) s->footer_buf;
 | |
| 
 | |
|     if (be32_to_cpu(footer->type) == VHD_FIXED) {
 | |
|         return bdrv_write(bs->file, sector_num, buf, nb_sectors);
 | |
|     }
 | |
|     while (nb_sectors > 0) {
 | |
|         offset = get_sector_offset(bs, sector_num, 1);
 | |
| 
 | |
|         sectors_per_block = s->block_size >> BDRV_SECTOR_BITS;
 | |
|         sectors = sectors_per_block - (sector_num % sectors_per_block);
 | |
|         if (sectors > nb_sectors) {
 | |
|             sectors = nb_sectors;
 | |
|         }
 | |
| 
 | |
|         if (offset == -1) {
 | |
|             offset = alloc_block(bs, sector_num);
 | |
|             if (offset < 0)
 | |
|                 return -1;
 | |
|         }
 | |
| 
 | |
|         ret = bdrv_pwrite(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE);
 | |
|         if (ret != sectors * BDRV_SECTOR_SIZE) {
 | |
|             return -1;
 | |
|         }
 | |
| 
 | |
|         nb_sectors -= sectors;
 | |
|         sector_num += sectors;
 | |
|         buf += sectors * BDRV_SECTOR_SIZE;
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num,
 | |
|                                      const uint8_t *buf, int nb_sectors)
 | |
| {
 | |
|     int ret;
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     qemu_co_mutex_lock(&s->lock);
 | |
|     ret = vpc_write(bs, sector_num, buf, nb_sectors);
 | |
|     qemu_co_mutex_unlock(&s->lock);
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Calculates the number of cylinders, heads and sectors per cylinder
 | |
|  * based on a given number of sectors. This is the algorithm described
 | |
|  * in the VHD specification.
 | |
|  *
 | |
|  * Note that the geometry doesn't always exactly match total_sectors but
 | |
|  * may round it down.
 | |
|  *
 | |
|  * Returns 0 on success, -EFBIG if the size is larger than ~2 TB. Override
 | |
|  * the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB)
 | |
|  * and instead allow up to 255 heads.
 | |
|  */
 | |
| static int calculate_geometry(int64_t total_sectors, uint16_t* cyls,
 | |
|     uint8_t* heads, uint8_t* secs_per_cyl)
 | |
| {
 | |
|     uint32_t cyls_times_heads;
 | |
| 
 | |
|     /* Allow a maximum disk size of approximately 2 TB */
 | |
|     if (total_sectors > 65535LL * 255 * 255) {
 | |
|         return -EFBIG;
 | |
|     }
 | |
| 
 | |
|     if (total_sectors > 65535 * 16 * 63) {
 | |
|         *secs_per_cyl = 255;
 | |
|         if (total_sectors > 65535 * 16 * 255) {
 | |
|             *heads = 255;
 | |
|         } else {
 | |
|             *heads = 16;
 | |
|         }
 | |
|         cyls_times_heads = total_sectors / *secs_per_cyl;
 | |
|     } else {
 | |
|         *secs_per_cyl = 17;
 | |
|         cyls_times_heads = total_sectors / *secs_per_cyl;
 | |
|         *heads = (cyls_times_heads + 1023) / 1024;
 | |
| 
 | |
|         if (*heads < 4)
 | |
|             *heads = 4;
 | |
| 
 | |
|         if (cyls_times_heads >= (*heads * 1024) || *heads > 16) {
 | |
|             *secs_per_cyl = 31;
 | |
|             *heads = 16;
 | |
|             cyls_times_heads = total_sectors / *secs_per_cyl;
 | |
|         }
 | |
| 
 | |
|         if (cyls_times_heads >= (*heads * 1024)) {
 | |
|             *secs_per_cyl = 63;
 | |
|             *heads = 16;
 | |
|             cyls_times_heads = total_sectors / *secs_per_cyl;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     *cyls = cyls_times_heads / *heads;
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf,
 | |
|                                int64_t total_sectors)
 | |
| {
 | |
|     VHDDynDiskHeader *dyndisk_header =
 | |
|         (VHDDynDiskHeader *) buf;
 | |
|     size_t block_size, num_bat_entries;
 | |
|     int i;
 | |
|     int ret;
 | |
|     int64_t offset = 0;
 | |
| 
 | |
|     // Write the footer (twice: at the beginning and at the end)
 | |
|     block_size = 0x200000;
 | |
|     num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512);
 | |
| 
 | |
|     ret = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE);
 | |
|     if (ret) {
 | |
|         goto fail;
 | |
|     }
 | |
| 
 | |
|     offset = 1536 + ((num_bat_entries * 4 + 511) & ~511);
 | |
|     ret = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE);
 | |
|     if (ret < 0) {
 | |
|         goto fail;
 | |
|     }
 | |
| 
 | |
|     // Write the initial BAT
 | |
|     offset = 3 * 512;
 | |
| 
 | |
|     memset(buf, 0xFF, 512);
 | |
|     for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) {
 | |
|         ret = bdrv_pwrite_sync(bs, offset, buf, 512);
 | |
|         if (ret < 0) {
 | |
|             goto fail;
 | |
|         }
 | |
|         offset += 512;
 | |
|     }
 | |
| 
 | |
|     // Prepare the Dynamic Disk Header
 | |
|     memset(buf, 0, 1024);
 | |
| 
 | |
|     memcpy(dyndisk_header->magic, "cxsparse", 8);
 | |
| 
 | |
|     /*
 | |
|      * Note: The spec is actually wrong here for data_offset, it says
 | |
|      * 0xFFFFFFFF, but MS tools expect all 64 bits to be set.
 | |
|      */
 | |
|     dyndisk_header->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL);
 | |
|     dyndisk_header->table_offset = cpu_to_be64(3 * 512);
 | |
|     dyndisk_header->version = cpu_to_be32(0x00010000);
 | |
|     dyndisk_header->block_size = cpu_to_be32(block_size);
 | |
|     dyndisk_header->max_table_entries = cpu_to_be32(num_bat_entries);
 | |
| 
 | |
|     dyndisk_header->checksum = cpu_to_be32(vpc_checksum(buf, 1024));
 | |
| 
 | |
|     // Write the header
 | |
|     offset = 512;
 | |
| 
 | |
|     ret = bdrv_pwrite_sync(bs, offset, buf, 1024);
 | |
|     if (ret < 0) {
 | |
|         goto fail;
 | |
|     }
 | |
| 
 | |
|  fail:
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static int create_fixed_disk(BlockDriverState *bs, uint8_t *buf,
 | |
|                              int64_t total_size)
 | |
| {
 | |
|     int ret;
 | |
| 
 | |
|     /* Add footer to total size */
 | |
|     total_size += HEADER_SIZE;
 | |
| 
 | |
|     ret = bdrv_truncate(bs, total_size);
 | |
|     if (ret < 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     ret = bdrv_pwrite_sync(bs, total_size - HEADER_SIZE, buf, HEADER_SIZE);
 | |
|     if (ret < 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
 | |
| {
 | |
|     uint8_t buf[1024];
 | |
|     VHDFooter *footer = (VHDFooter *) buf;
 | |
|     char *disk_type_param;
 | |
|     int i;
 | |
|     uint16_t cyls = 0;
 | |
|     uint8_t heads = 0;
 | |
|     uint8_t secs_per_cyl = 0;
 | |
|     int64_t total_sectors;
 | |
|     int64_t total_size;
 | |
|     int disk_type;
 | |
|     int ret = -EIO;
 | |
|     Error *local_err = NULL;
 | |
|     BlockDriverState *bs = NULL;
 | |
| 
 | |
|     /* Read out options */
 | |
|     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 | |
|                           BDRV_SECTOR_SIZE);
 | |
|     disk_type_param = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);
 | |
|     if (disk_type_param) {
 | |
|         if (!strcmp(disk_type_param, "dynamic")) {
 | |
|             disk_type = VHD_DYNAMIC;
 | |
|         } else if (!strcmp(disk_type_param, "fixed")) {
 | |
|             disk_type = VHD_FIXED;
 | |
|         } else {
 | |
|             ret = -EINVAL;
 | |
|             goto out;
 | |
|         }
 | |
|     } else {
 | |
|         disk_type = VHD_DYNAMIC;
 | |
|     }
 | |
| 
 | |
|     ret = bdrv_create_file(filename, opts, &local_err);
 | |
|     if (ret < 0) {
 | |
|         error_propagate(errp, local_err);
 | |
|         goto out;
 | |
|     }
 | |
|     ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
 | |
|                     NULL, &local_err);
 | |
|     if (ret < 0) {
 | |
|         error_propagate(errp, local_err);
 | |
|         goto out;
 | |
|     }
 | |
| 
 | |
|     /*
 | |
|      * Calculate matching total_size and geometry. Increase the number of
 | |
|      * sectors requested until we get enough (or fail). This ensures that
 | |
|      * qemu-img convert doesn't truncate images, but rather rounds up.
 | |
|      */
 | |
|     total_sectors = total_size / BDRV_SECTOR_SIZE;
 | |
|     for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
 | |
|         if (calculate_geometry(total_sectors + i, &cyls, &heads,
 | |
|                                &secs_per_cyl))
 | |
|         {
 | |
|             ret = -EFBIG;
 | |
|             goto out;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     total_sectors = (int64_t) cyls * heads * secs_per_cyl;
 | |
| 
 | |
|     /* Prepare the Hard Disk Footer */
 | |
|     memset(buf, 0, 1024);
 | |
| 
 | |
|     memcpy(footer->creator, "conectix", 8);
 | |
|     /* TODO Check if "qemu" creator_app is ok for VPC */
 | |
|     memcpy(footer->creator_app, "qemu", 4);
 | |
|     memcpy(footer->creator_os, "Wi2k", 4);
 | |
| 
 | |
|     footer->features = cpu_to_be32(0x02);
 | |
|     footer->version = cpu_to_be32(0x00010000);
 | |
|     if (disk_type == VHD_DYNAMIC) {
 | |
|         footer->data_offset = cpu_to_be64(HEADER_SIZE);
 | |
|     } else {
 | |
|         footer->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL);
 | |
|     }
 | |
|     footer->timestamp = cpu_to_be32(time(NULL) - VHD_TIMESTAMP_BASE);
 | |
| 
 | |
|     /* Version of Virtual PC 2007 */
 | |
|     footer->major = cpu_to_be16(0x0005);
 | |
|     footer->minor = cpu_to_be16(0x0003);
 | |
|     if (disk_type == VHD_DYNAMIC) {
 | |
|         footer->orig_size = cpu_to_be64(total_sectors * 512);
 | |
|         footer->size = cpu_to_be64(total_sectors * 512);
 | |
|     } else {
 | |
|         footer->orig_size = cpu_to_be64(total_size);
 | |
|         footer->size = cpu_to_be64(total_size);
 | |
|     }
 | |
|     footer->cyls = cpu_to_be16(cyls);
 | |
|     footer->heads = heads;
 | |
|     footer->secs_per_cyl = secs_per_cyl;
 | |
| 
 | |
|     footer->type = cpu_to_be32(disk_type);
 | |
| 
 | |
| #if defined(CONFIG_UUID)
 | |
|     uuid_generate(footer->uuid);
 | |
| #endif
 | |
| 
 | |
|     footer->checksum = cpu_to_be32(vpc_checksum(buf, HEADER_SIZE));
 | |
| 
 | |
|     if (disk_type == VHD_DYNAMIC) {
 | |
|         ret = create_dynamic_disk(bs, buf, total_sectors);
 | |
|     } else {
 | |
|         ret = create_fixed_disk(bs, buf, total_size);
 | |
|     }
 | |
| 
 | |
| out:
 | |
|     bdrv_unref(bs);
 | |
|     g_free(disk_type_param);
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static int vpc_has_zero_init(BlockDriverState *bs)
 | |
| {
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     VHDFooter *footer =  (VHDFooter *) s->footer_buf;
 | |
| 
 | |
|     if (be32_to_cpu(footer->type) == VHD_FIXED) {
 | |
|         return bdrv_has_zero_init(bs->file);
 | |
|     } else {
 | |
|         return 1;
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void vpc_close(BlockDriverState *bs)
 | |
| {
 | |
|     BDRVVPCState *s = bs->opaque;
 | |
|     qemu_vfree(s->pagetable);
 | |
| #ifdef CACHE
 | |
|     g_free(s->pageentry_u8);
 | |
| #endif
 | |
| 
 | |
|     migrate_del_blocker(s->migration_blocker);
 | |
|     error_free(s->migration_blocker);
 | |
| }
 | |
| 
 | |
| static QemuOptsList vpc_create_opts = {
 | |
|     .name = "vpc-create-opts",
 | |
|     .head = QTAILQ_HEAD_INITIALIZER(vpc_create_opts.head),
 | |
|     .desc = {
 | |
|         {
 | |
|             .name = BLOCK_OPT_SIZE,
 | |
|             .type = QEMU_OPT_SIZE,
 | |
|             .help = "Virtual disk size"
 | |
|         },
 | |
|         {
 | |
|             .name = BLOCK_OPT_SUBFMT,
 | |
|             .type = QEMU_OPT_STRING,
 | |
|             .help =
 | |
|                 "Type of virtual hard disk format. Supported formats are "
 | |
|                 "{dynamic (default) | fixed} "
 | |
|         },
 | |
|         {
 | |
|             .name = BLOCK_OPT_NOCOW,
 | |
|             .type = QEMU_OPT_BOOL,
 | |
|             .help = "Turn off copy-on-write (valid only on btrfs)"
 | |
|         },
 | |
|         { /* end of list */ }
 | |
|     }
 | |
| };
 | |
| 
 | |
| static BlockDriver bdrv_vpc = {
 | |
|     .format_name    = "vpc",
 | |
|     .instance_size  = sizeof(BDRVVPCState),
 | |
| 
 | |
|     .bdrv_probe             = vpc_probe,
 | |
|     .bdrv_open              = vpc_open,
 | |
|     .bdrv_close             = vpc_close,
 | |
|     .bdrv_reopen_prepare    = vpc_reopen_prepare,
 | |
|     .bdrv_create            = vpc_create,
 | |
| 
 | |
|     .bdrv_read              = vpc_co_read,
 | |
|     .bdrv_write             = vpc_co_write,
 | |
| 
 | |
|     .bdrv_get_info          = vpc_get_info,
 | |
| 
 | |
|     .create_opts            = &vpc_create_opts,
 | |
|     .bdrv_has_zero_init     = vpc_has_zero_init,
 | |
| };
 | |
| 
 | |
| static void bdrv_vpc_init(void)
 | |
| {
 | |
|     bdrv_register(&bdrv_vpc);
 | |
| }
 | |
| 
 | |
| block_init(bdrv_vpc_init);
 |