/*
* 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 "qemu-common.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((char *)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,
};
