Bochs/bochs/iodev/hdimage/vmware4.cc
Volker Ruppert 35ec96f740 - implemented restore function for 'vmeare3' mode images
- 'vmware4' image mode: handle restore failure
2012-09-26 16:20:38 +00:00

361 lines
11 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
/*
* This file provides support for VMWare's virtual disk image
* format version 4 and above.
*
* Author: Sharvil Nanavati
* Contact: snrrrub@gmail.com
*
* Copyright (C) 2006 Sharvil Nanavati.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
// Define BX_PLUGGABLE in files that can be compiled into plugins. For
// platforms that require a special tag on exported symbols, BX_PLUGGABLE
// is used to know when we are exporting symbols and when we are importing.
#define BX_PLUGGABLE
#include "iodev.h"
#include "hdimage.h"
#include "vmware4.h"
#define LOG_THIS bx_devices.pluginHDImageCtl->
const off_t vmware4_image_t::INVALID_OFFSET = (off_t)-1;
const int vmware4_image_t::SECTOR_SIZE = 512;
vmware4_image_t::vmware4_image_t()
: file_descriptor(-1),
tlb(0),
tlb_offset(INVALID_OFFSET),
current_offset(INVALID_OFFSET),
is_dirty(0)
{
}
vmware4_image_t::~vmware4_image_t()
{
close();
}
int vmware4_image_t::open(const char* _pathname)
{
pathname = _pathname;
close();
int flags = O_RDWR;
#ifdef O_BINARY
flags |= O_BINARY;
#endif
file_descriptor = ::open(pathname, flags);
if (!is_open())
return -1;
if (!read_header())
BX_PANIC(("unable to read vmware4 virtual disk header from file '%s'", pathname));
tlb = new Bit8u[(unsigned)header.tlb_size_sectors * SECTOR_SIZE];
if (tlb == 0)
BX_PANIC(("unable to allocate " FMT_LL "d bytes for vmware4 image's tlb", header.tlb_size_sectors * SECTOR_SIZE));
tlb_offset = INVALID_OFFSET;
current_offset = 0;
is_dirty = 0;
hd_size = header.total_sectors * SECTOR_SIZE;
cylinders = (unsigned)hd_size / (16 * 63);
heads = 16;
spt = 63;
BX_DEBUG(("VMware 4 disk geometry:"));
BX_DEBUG((" .size = " FMT_LL "d", hd_size));
BX_DEBUG((" .cylinders = %d", cylinders));
BX_DEBUG((" .heads = %d", heads));
BX_DEBUG((" .sectors = %d", spt));
return 1;
}
void vmware4_image_t::close()
{
if (file_descriptor == -1)
return;
flush();
delete [] tlb; tlb = 0;
::close(file_descriptor);
file_descriptor = -1;
}
Bit64s vmware4_image_t::lseek(Bit64s offset, int whence)
{
switch (whence) {
case SEEK_SET:
current_offset = (off_t)offset;
return current_offset;
case SEEK_CUR:
current_offset += (off_t)offset;
return current_offset;
case SEEK_END:
current_offset = header.total_sectors * SECTOR_SIZE + (off_t)offset;
return current_offset;
default:
BX_DEBUG(("unknown 'whence' value (%d) when trying to seek vmware4 image", whence));
return INVALID_OFFSET;
}
}
ssize_t vmware4_image_t::read(void * buf, size_t count)
{
ssize_t total = 0;
while (count > 0) {
off_t readable = perform_seek();
if (readable == INVALID_OFFSET) {
BX_DEBUG(("vmware4 disk image read failed on %u bytes at " FMT_LL "d", (unsigned)count, current_offset));
return -1;
}
off_t copysize = ((off_t)count > readable) ? readable : count;
memcpy(buf, tlb + current_offset - tlb_offset, (size_t)copysize);
current_offset += copysize;
total += (long)copysize;
count -= (size_t)copysize;
}
return total;
}
ssize_t vmware4_image_t::write(const void * buf, size_t count)
{
ssize_t total = 0;
while (count > 0) {
off_t writable = perform_seek();
if (writable == INVALID_OFFSET) {
BX_DEBUG(("vmware4 disk image write failed on %u bytes at " FMT_LL "d", (unsigned)count, current_offset));
return -1;
}
off_t writesize = ((off_t)count > writable) ? writable : count;
memcpy(tlb + current_offset - tlb_offset, buf, (size_t)writesize);
current_offset += writesize;
total += (long)writesize;
count -= (size_t)writesize;
is_dirty = 1;
}
return total;
}
bx_bool vmware4_image_t::is_open() const
{
return (file_descriptor != -1);
}
bx_bool vmware4_image_t::is_valid_header() const
{
if (header.id[0] != 'K' || header.id[1] != 'D' || header.id[2] != 'M' ||
header.id[3] != 'V') {
BX_DEBUG(("not a vmware4 image"));
return 0;
}
if (header.version != 1) {
BX_DEBUG(("unsupported vmware4 image version"));
return 0;
}
return 1;
}
bx_bool vmware4_image_t::read_header()
{
if (!is_open())
BX_PANIC(("attempt to read vmware4 header from a closed file"));
if (::read(file_descriptor, &header, sizeof(VM4_Header)) != sizeof(VM4_Header))
return 0;
header.version = dtoh32(header.version);
header.flags = dtoh32(header.flags);
header.total_sectors = dtoh64(header.total_sectors);
header.tlb_size_sectors = dtoh64(header.tlb_size_sectors);
header.description_offset_sectors = dtoh64(header.description_offset_sectors);
header.description_size_sectors = dtoh64(header.description_size_sectors);
header.slb_count = dtoh32(header.slb_count);
header.flb_offset_sectors = dtoh64(header.flb_offset_sectors);
header.flb_copy_offset_sectors = dtoh64(header.flb_copy_offset_sectors);
header.tlb_offset_sectors = dtoh64(header.tlb_offset_sectors);
if(!is_valid_header())
BX_PANIC(("invalid vmware4 virtual disk image"));
BX_DEBUG(("VM4_Header (size=%u)", (unsigned)sizeof(VM4_Header)));
BX_DEBUG((" .version = %d", header.version));
BX_DEBUG((" .flags = %d", header.flags));
BX_DEBUG((" .total_sectors = " FMT_LL "d", header.total_sectors));
BX_DEBUG((" .tlb_size_sectors = " FMT_LL "d", header.tlb_size_sectors));
BX_DEBUG((" .description_offset_sectors = " FMT_LL "d", header.description_offset_sectors));
BX_DEBUG((" .description_size_sectors = " FMT_LL "d", header.description_size_sectors));
BX_DEBUG((" .slb_count = %d", header.slb_count));
BX_DEBUG((" .flb_offset_sectors = " FMT_LL "d", header.flb_offset_sectors));
BX_DEBUG((" .flb_copy_offset_sectors = " FMT_LL "d", header.flb_copy_offset_sectors));
BX_DEBUG((" .tlb_offset_sectors = " FMT_LL "d", header.tlb_offset_sectors));
return 1;
}
//
// Returns the number of bytes that can be read from the current offset before needing
// to perform another seek.
//
off_t vmware4_image_t::perform_seek()
{
if (current_offset == INVALID_OFFSET) {
BX_DEBUG(("invalid offset specified in vmware4 seek"));
return INVALID_OFFSET;
}
//
// The currently loaded tlb can service the request.
//
if (tlb_offset / (header.tlb_size_sectors * SECTOR_SIZE) == current_offset / (header.tlb_size_sectors * SECTOR_SIZE))
return (header.tlb_size_sectors * SECTOR_SIZE) - (current_offset - tlb_offset);
flush();
Bit64u index = current_offset / (header.tlb_size_sectors * SECTOR_SIZE);
Bit32u slb_index = (Bit32u)(index % header.slb_count);
Bit32u flb_index = (Bit32u)(index / header.slb_count);
Bit32u slb_sector = read_block_index(header.flb_offset_sectors, flb_index);
Bit32u slb_copy_sector = read_block_index(header.flb_copy_offset_sectors, flb_index);
if (slb_sector == 0 && slb_copy_sector == 0) {
BX_DEBUG(("loaded vmware4 disk image requires un-implemented feature"));
return INVALID_OFFSET;
}
if (slb_sector == 0)
slb_sector = slb_copy_sector;
Bit32u tlb_sector = read_block_index(slb_sector, slb_index);
tlb_offset = index * header.tlb_size_sectors * SECTOR_SIZE;
if (tlb_sector == 0) {
//
// Allocate a new tlb
//
memset(tlb, 0, (size_t)header.tlb_size_sectors * SECTOR_SIZE);
//
// Instead of doing a write to increase the file size, we could use
// ftruncate but it is not portable.
//
off_t eof = ((::lseek(file_descriptor, 0, SEEK_END) + SECTOR_SIZE - 1) / SECTOR_SIZE) * SECTOR_SIZE;
::write(file_descriptor, tlb, (unsigned)header.tlb_size_sectors * SECTOR_SIZE);
tlb_sector = (Bit32u)eof / SECTOR_SIZE;
write_block_index(slb_sector, slb_index, tlb_sector);
write_block_index(slb_copy_sector, slb_index, tlb_sector);
::lseek(file_descriptor, eof, SEEK_SET);
} else {
::lseek(file_descriptor, tlb_sector * SECTOR_SIZE, SEEK_SET);
::read(file_descriptor, tlb, (unsigned)header.tlb_size_sectors * SECTOR_SIZE);
::lseek(file_descriptor, tlb_sector * SECTOR_SIZE, SEEK_SET);
}
return (header.tlb_size_sectors * SECTOR_SIZE) - (current_offset - tlb_offset);
}
void vmware4_image_t::flush()
{
if (!is_dirty)
return;
//
// Write dirty sectors to disk first. Assume that the file is already at the
// position for the current tlb.
//
::write(file_descriptor, tlb, (unsigned)header.tlb_size_sectors * SECTOR_SIZE);
is_dirty = 0;
}
Bit32u vmware4_image_t::read_block_index(Bit64u sector, Bit32u index)
{
Bit32u ret;
bx_read_image(file_descriptor, sector * SECTOR_SIZE + index * sizeof(Bit32u),
&ret, sizeof(Bit32u));
return dtoh32(ret);
}
void vmware4_image_t::write_block_index(Bit64u sector, Bit32u index, Bit32u block_sector)
{
block_sector = htod32(block_sector);
bx_write_image(file_descriptor, sector * SECTOR_SIZE + index * sizeof(Bit32u),
&block_sector, sizeof(Bit32u));
}
Bit32u vmware4_image_t::get_capabilities(void)
{
return HDIMAGE_HAS_GEOMETRY;
}
bx_bool vmware4_image_t::save_state(const char *backup_fname)
{
return hdimage_backup_file(file_descriptor, backup_fname);
}
void vmware4_image_t::restore_state(const char *backup_fname)
{
VM4_Header temp_header;
int backup_fd = ::open(backup_fname, O_RDONLY
#ifdef O_BINARY
| O_BINARY
#endif
);
if (backup_fd < 0) {
BX_PANIC(("Could not open vmware4 image backup"));
return;
}
if (::read(backup_fd, &temp_header, sizeof(VM4_Header)) != sizeof(VM4_Header)) {
::close(backup_fd);
BX_PANIC(("Could not read vmware4 image header"));
return;
}
::close(backup_fd);
if ((temp_header.id[0] != 'K') || (temp_header.id[1] != 'D') ||
(temp_header.id[2] != 'M') || (temp_header.id[3] != 'V') ||
(header.version != 1)) {
BX_PANIC(("Could not detect vmware4 image header"));
return;
}
close();
if (!hdimage_copy_file(backup_fname, pathname)) {
BX_PANIC(("Failed to restore vmware4 image '%s'", pathname));
return;
}
open(pathname);
}