[qemu.git] / block-vpc.c

/*
 * Block driver for Conectix/Microsoft Virtual PC images
 * 
 * Copyright (c) 2005 Alex Beregszaszi
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "vl.h"
#include "block_int.h"

/**************************************************************/

#define HEADER_SIZE 512

//#define CACHE

// always big-endian
struct vpc_subheader {
    char magic[8]; // "conectix" / "cxsparse"
    union {
	struct {
	    uint32_t unk1[2];
	    uint32_t unk2; // always zero?
	    uint32_t subheader_offset;
	    uint32_t unk3; // some size?
	    char creator[4]; // "vpc "
	    uint16_t major;
	    uint16_t minor;
	    char guest[4]; // "Wi2k"
	    uint32_t unk4[7];
	    uint8_t vnet_id[16]; // virtual network id, purpose unknown
	    // next 16 longs are used, but dunno the purpose
	    // next 6 longs unknown, following 7 long maybe a serial
	    char padding[HEADER_SIZE - 84];
	} main;
	struct {
	    uint32_t unk1[2]; // all bits set
	    uint32_t unk2; // always zero?
	    uint32_t pagetable_offset;
	    uint32_t unk3;
	    uint32_t pagetable_entries; // 32bit/entry
	    uint32_t pageentry_size; // 512*8*512
	    uint32_t nb_sectors;
	    char padding[HEADER_SIZE - 40];
	} sparse;
	char padding[HEADER_SIZE - 8];
    } type;
};

typedef struct BDRVVPCState {
    int fd;
    
    int pagetable_entries;
    uint32_t *pagetable;

    uint32_t pageentry_size;
#ifdef CACHE
    uint8_t *pageentry_u8;
    uint32_t *pageentry_u32;
    uint16_t *pageentry_u16;
    
    uint64_t last_bitmap;
#endif
} BDRVVPCState;

static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
{
    if (buf_size >= 8 && !strncmp(buf, "conectix", 8))
	return 100;
    return 0;
}

static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVVPCState *s = bs->opaque;
    int fd, i;
    struct vpc_subheader header;

    fd = open(filename, O_RDONLY | O_BINARY);
    if (fd < 0)
        return -1;

    bs->read_only = 1; // no write support yet
    
    s->fd = fd;

    if (read(fd, &header, HEADER_SIZE) != HEADER_SIZE)
        goto fail;

    if (strncmp(header.magic, "conectix", 8))
        goto fail;
    lseek(s->fd, be32_to_cpu(header.type.main.subheader_offset), SEEK_SET);

    if (read(fd, &header, HEADER_SIZE) != HEADER_SIZE)
        goto fail;

    if (strncmp(header.magic, "cxsparse", 8))
	goto fail;

    bs->total_sectors = ((uint64_t)be32_to_cpu(header.type.sparse.pagetable_entries) *
			be32_to_cpu(header.type.sparse.pageentry_size)) / 512;

    lseek(s->fd, be32_to_cpu(header.type.sparse.pagetable_offset), SEEK_SET);

    s->pagetable_entries = be32_to_cpu(header.type.sparse.pagetable_entries);
    s->pagetable = qemu_malloc(s->pagetable_entries * 4);
    if (!s->pagetable)
	goto fail;
    if (read(s->fd, s->pagetable, s->pagetable_entries * 4) !=
	s->pagetable_entries * 4)
	goto fail;
    for (i = 0; i < s->pagetable_entries; i++)
	be32_to_cpus(&s->pagetable[i]);

    s->pageentry_size = be32_to_cpu(header.type.sparse.pageentry_size);
#ifdef CACHE
    s->pageentry_u8 = qemu_malloc(512);
    if (!s->pageentry_u8)
	goto fail;
    s->pageentry_u32 = s->pageentry_u8;
    s->pageentry_u16 = s->pageentry_u8;
    s->last_pagetable = -1;
#endif

    return 0;
 fail:
    close(fd);
    return -1;
}

static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
{
    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->pageentry_size;
    pageentry_index = (offset % s->pageentry_size) / 512;
    
    if (pagetable_index > s->pagetable_entries || s->pagetable[pagetable_index] == 0xffffffff)
	return -1; // not allocated

    bitmap_offset = 512 * s->pagetable[pagetable_index];
    block_offset = bitmap_offset + 512 + (512 * pageentry_index);
    
//    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
    lseek(s->fd, block_offset, SEEK_SET);

    return 0;
}

static int vpc_read(BlockDriverState *bs, int64_t sector_num, 
                    uint8_t *buf, int nb_sectors)
{
    BDRVVPCState *s = bs->opaque;
    int ret;

    while (nb_sectors > 0) {
	if (!seek_to_sector(bs, sector_num))
	{
	    ret = read(s->fd, buf, 512);
	    if (ret != 512)
		return -1;
	}
	else
            memset(buf, 0, 512);
        nb_sectors--;
        sector_num++;
        buf += 512;
    }
    return 0;
}

static void vpc_close(BlockDriverState *bs)
{
    BDRVVPCState *s = bs->opaque;
    qemu_free(s->pagetable);
#ifdef CACHE
    qemu_free(s->pageentry_u8);
#endif
    close(s->fd);
}

BlockDriver bdrv_vpc = {
    "vpc",
    sizeof(BDRVVPCState),
    vpc_probe,
    vpc_open,
    vpc_read,
    NULL,
    vpc_close,
};
Commit	Line	Data
6a0f9e82 FB	1	/*
	2	* Block driver for Conectix/Microsoft Virtual PC images
	3	*
	4	* Copyright (c) 2005 Alex Beregszaszi
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24	#include "vl.h"
	25	#include "block_int.h"
	26
	27	/**************************************************************/
	28
	29	#define HEADER_SIZE 512
	30
	31	//#define CACHE
	32
	33	// always big-endian
	34	struct vpc_subheader {
	35	char magic[8]; // "conectix" / "cxsparse"
	36	union {
	37	struct {
	38	uint32_t unk1[2];
	39	uint32_t unk2; // always zero?
	40	uint32_t subheader_offset;
	41	uint32_t unk3; // some size?
	42	char creator[4]; // "vpc "
	43	uint16_t major;
	44	uint16_t minor;
	45	char guest[4]; // "Wi2k"
	46	uint32_t unk4[7];
	47	uint8_t vnet_id[16]; // virtual network id, purpose unknown
	48	// next 16 longs are used, but dunno the purpose
	49	// next 6 longs unknown, following 7 long maybe a serial
	50	char padding[HEADER_SIZE - 84];
	51	} main;
	52	struct {
	53	uint32_t unk1[2]; // all bits set
	54	uint32_t unk2; // always zero?
	55	uint32_t pagetable_offset;
	56	uint32_t unk3;
	57	uint32_t pagetable_entries; // 32bit/entry
	58	uint32_t pageentry_size; // 5128512
	59	uint32_t nb_sectors;
	60	char padding[HEADER_SIZE - 40];
	61	} sparse;
	62	char padding[HEADER_SIZE - 8];
	63	} type;
	64	};
65
66	typedef struct BDRVVPCState {
67	int fd;
68
69	int pagetable_entries;
70	uint32_t *pagetable;
71
72	uint32_t pageentry_size;
73	#ifdef CACHE
74	uint8_t *pageentry_u8;
75	uint32_t *pageentry_u32;
76	uint16_t *pageentry_u16;
77
78	uint64_t last_bitmap;
79	#endif
80	} BDRVVPCState;
81
82	static int vpc_probe(const uint8_t buf, int buf_size, const char filename)
83	{
712e7874	84	if (buf_size >= 8 && !strncmp(buf, "conectix", 8))
6a0f9e82	85	return 100;
6a0f9e82 FB	86	return 0;
	87	}
	88
83f64091	89	static int vpc_open(BlockDriverState bs, const char filename, int flags)
6a0f9e82 FB	90	{
	91	BDRVVPCState *s = bs->opaque;
	92	int fd, i;
	93	struct vpc_subheader header;
	94
83f64091 FB	95	fd = open(filename, O_RDONLY \| O_BINARY);
	96	if (fd < 0)
	97	return -1;
	98
6a0f9e82 FB	99	bs->read_only = 1; // no write support yet
	100
	101	s->fd = fd;
	102
	103	if (read(fd, &header, HEADER_SIZE) != HEADER_SIZE)
	104	goto fail;
	105
	106	if (strncmp(header.magic, "conectix", 8))
	107	goto fail;
	108	lseek(s->fd, be32_to_cpu(header.type.main.subheader_offset), SEEK_SET);
	109
	110	if (read(fd, &header, HEADER_SIZE) != HEADER_SIZE)
	111	goto fail;
	112
	113	if (strncmp(header.magic, "cxsparse", 8))
	114	goto fail;
	115
	116	bs->total_sectors = ((uint64_t)be32_to_cpu(header.type.sparse.pagetable_entries) *
	117	be32_to_cpu(header.type.sparse.pageentry_size)) / 512;
	118
	119	lseek(s->fd, be32_to_cpu(header.type.sparse.pagetable_offset), SEEK_SET);
	120
	121	s->pagetable_entries = be32_to_cpu(header.type.sparse.pagetable_entries);
	122	s->pagetable = qemu_malloc(s->pagetable_entries * 4);
	123	if (!s->pagetable)
	124	goto fail;
	125	if (read(s->fd, s->pagetable, s->pagetable_entries * 4) !=
	126	s->pagetable_entries * 4)
	127	goto fail;
	128	for (i = 0; i < s->pagetable_entries; i++)
	129	be32_to_cpus(&s->pagetable[i]);
	130
	131	s->pageentry_size = be32_to_cpu(header.type.sparse.pageentry_size);
	132	#ifdef CACHE
	133	s->pageentry_u8 = qemu_malloc(512);
	134	if (!s->pageentry_u8)
	135	goto fail;
	136	s->pageentry_u32 = s->pageentry_u8;
	137	s->pageentry_u16 = s->pageentry_u8;
	138	s->last_pagetable = -1;
	139	#endif
	140
	141	return 0;
	142	fail:
	143	close(fd);
	144	return -1;
	145	}
	146
	147	static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
	148	{
	149	BDRVVPCState *s = bs->opaque;
	150	uint64_t offset = sector_num * 512;
	151	uint64_t bitmap_offset, block_offset;
	152	uint32_t pagetable_index, pageentry_index;
	153
	154	pagetable_index = offset / s->pageentry_size;
	155	pageentry_index = (offset % s->pageentry_size) / 512;
	156
	157	if (pagetable_index > s->pagetable_entries \|\| s->pagetable[pagetable_index] == 0xffffffff)
	158	return -1; // not allocated
	159
	160	bitmap_offset = 512 * s->pagetable[pagetable_index];
	161	block_offset = bitmap_offset + 512 + (512 * pageentry_index);
	162
26a76461	163	// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",
6a0f9e82 FB	164	// sector_num, pagetable_index, pageentry_index,
	165	// bitmap_offset, block_offset);
	166
	167	// disabled by reason
	168	#if 0
	169	#ifdef CACHE
	170	if (bitmap_offset != s->last_bitmap)
	171	{
	172	lseek(s->fd, bitmap_offset, SEEK_SET);
	173
	174	s->last_bitmap = bitmap_offset;
	175
	176	// Scary! Bitmap is stored as big endian 32bit entries,
	177	// while we used to look it up byte by byte
	178	read(s->fd, s->pageentry_u8, 512);
	179	for (i = 0; i < 128; i++)
	180	be32_to_cpus(&s->pageentry_u32[i]);
	181	}
	182
	183	if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1)
	184	return -1;
	185	#else
	186	lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET);
	187
	188	read(s->fd, &bitmap_entry, 1);
	189
	190	if ((bitmap_entry >> (pageentry_index % 8)) & 1)
	191	return -1; // not allocated
	192	#endif
	193	#endif
	194	lseek(s->fd, block_offset, SEEK_SET);
	195
	196	return 0;
	197	}
	198
	199	static int vpc_read(BlockDriverState *bs, int64_t sector_num,
	200	uint8_t *buf, int nb_sectors)
	201	{
	202	BDRVVPCState *s = bs->opaque;
	203	int ret;
	204
	205	while (nb_sectors > 0) {
	206	if (!seek_to_sector(bs, sector_num))
	207	{
	208	ret = read(s->fd, buf, 512);
	209	if (ret != 512)
	210	return -1;
	211	}
	212	else
	213	memset(buf, 0, 512);
	214	nb_sectors--;
	215	sector_num++;
	216	buf += 512;
	217	}
	218	return 0;
	219	}
	220
	221	static void vpc_close(BlockDriverState *bs)
	222	{
	223	BDRVVPCState *s = bs->opaque;
	224	qemu_free(s->pagetable);
	225	#ifdef CACHE
	226	qemu_free(s->pageentry_u8);
	227	#endif
228	close(s->fd);
229	}
230
231	BlockDriver bdrv_vpc = {
232	"vpc",
233	sizeof(BDRVVPCState),
234	vpc_probe,
235	vpc_open,
236	vpc_read,
237	NULL,
238	vpc_close,
239	};