block: initial VHDX driver support framework - supports open and probe
This is the initial block driver framework for VHDX image support
(i.e. Hyper-V image file formats), that supports opening VHDX files, and
parsing the headers.
This commit does not yet enable:
- reading
- writing
- updating the header
- differencing files (images with parents)
- log replay / dirty logs (only clean images)
This is based on Microsoft's VHDX specification:
"VHDX Format Specification v0.95", published 4/12/2012
https://www.microsoft.com/en-us/download/details.aspx?id=29681
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Jeff Cody
Stefan Hajnoczi
parent
203cdba3bc
commit
e8d4e5ffdb
@ -2,6 +2,7 @@ block-obj-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat
|
||||
block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o
|
||||
block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
|
||||
block-obj-y += qed-check.o
|
||||
block-obj-y += vhdx.o
|
||||
block-obj-y += parallels.o blkdebug.o blkverify.o
|
||||
block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
|
||||
block-obj-$(CONFIG_POSIX) += raw-posix.o
|
||||
|
||||
853
block/vhdx.c
Normal file
853
block/vhdx.c
Normal file
@ -0,0 +1,853 @@
|
||||
/*
|
||||
* Block driver for Hyper-V VHDX Images
|
||||
*
|
||||
* Copyright (c) 2013 Red Hat, Inc.,
|
||||
*
|
||||
* Authors:
|
||||
* Jeff Cody <jcody@redhat.com>
|
||||
*
|
||||
* This is based on the "VHDX Format Specification v0.95", published 4/12/2012
|
||||
* by Microsoft:
|
||||
* https://www.microsoft.com/en-us/download/details.aspx?id=29681
|
||||
*
|
||||
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
|
||||
* See the COPYING.LIB file in the top-level directory.
|
||||
*
|
||||
*/
|
||||
|
||||
#include "qemu-common.h"
|
||||
#include "block/block_int.h"
|
||||
#include "qemu/module.h"
|
||||
#include "qemu/crc32c.h"
|
||||
#include "block/vhdx.h"
|
||||
|
||||
|
||||
/* Several metadata and region table data entries are identified by
|
||||
* guids in a MS-specific GUID format. */
|
||||
|
||||
|
||||
/* ------- Known Region Table GUIDs ---------------------- */
|
||||
static const MSGUID bat_guid = { .data1 = 0x2dc27766,
|
||||
.data2 = 0xf623,
|
||||
.data3 = 0x4200,
|
||||
.data4 = { 0x9d, 0x64, 0x11, 0x5e,
|
||||
0x9b, 0xfd, 0x4a, 0x08} };
|
||||
|
||||
static const MSGUID metadata_guid = { .data1 = 0x8b7ca206,
|
||||
.data2 = 0x4790,
|
||||
.data3 = 0x4b9a,
|
||||
.data4 = { 0xb8, 0xfe, 0x57, 0x5f,
|
||||
0x05, 0x0f, 0x88, 0x6e} };
|
||||
|
||||
|
||||
|
||||
/* ------- Known Metadata Entry GUIDs ---------------------- */
|
||||
static const MSGUID file_param_guid = { .data1 = 0xcaa16737,
|
||||
.data2 = 0xfa36,
|
||||
.data3 = 0x4d43,
|
||||
.data4 = { 0xb3, 0xb6, 0x33, 0xf0,
|
||||
0xaa, 0x44, 0xe7, 0x6b} };
|
||||
|
||||
static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224,
|
||||
.data2 = 0xcd1b,
|
||||
.data3 = 0x4876,
|
||||
.data4 = { 0xb2, 0x11, 0x5d, 0xbe,
|
||||
0xd8, 0x3b, 0xf4, 0xb8} };
|
||||
|
||||
static const MSGUID page83_guid = { .data1 = 0xbeca12ab,
|
||||
.data2 = 0xb2e6,
|
||||
.data3 = 0x4523,
|
||||
.data4 = { 0x93, 0xef, 0xc3, 0x09,
|
||||
0xe0, 0x00, 0xc7, 0x46} };
|
||||
|
||||
|
||||
static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7,
|
||||
.data2 = 0x445d,
|
||||
.data3 = 0x4471,
|
||||
.data4 = { 0x9c, 0xc9, 0xe9, 0x88,
|
||||
0x52, 0x51, 0xc5, 0x56} };
|
||||
|
||||
static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d,
|
||||
.data2 = 0xb30b,
|
||||
.data3 = 0x454d,
|
||||
.data4 = { 0xab, 0xf7, 0xd3,
|
||||
0xd8, 0x48, 0x34,
|
||||
0xab, 0x0c} };
|
||||
|
||||
static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d,
|
||||
.data2 = 0xa96f,
|
||||
.data3 = 0x4709,
|
||||
.data4 = { 0xba, 0x47, 0xf2,
|
||||
0x33, 0xa8, 0xfa,
|
||||
0xab, 0x5f} };
|
||||
|
||||
/* Each parent type must have a valid GUID; this is for parent images
|
||||
* of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would
|
||||
* need to make up our own QCOW2 GUID type */
|
||||
static const MSGUID parent_vhdx_guid = { .data1 = 0xb04aefb7,
|
||||
.data2 = 0xd19e,
|
||||
.data3 = 0x4a81,
|
||||
.data4 = { 0xb7, 0x89, 0x25, 0xb8,
|
||||
0xe9, 0x44, 0x59, 0x13} };
|
||||
|
||||
|
||||
#define META_FILE_PARAMETER_PRESENT 0x01
|
||||
#define META_VIRTUAL_DISK_SIZE_PRESENT 0x02
|
||||
#define META_PAGE_83_PRESENT 0x04
|
||||
#define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08
|
||||
#define META_PHYS_SECTOR_SIZE_PRESENT 0x10
|
||||
#define META_PARENT_LOCATOR_PRESENT 0x20
|
||||
|
||||
#define META_ALL_PRESENT \
|
||||
(META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \
|
||||
META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \
|
||||
META_PHYS_SECTOR_SIZE_PRESENT)
|
||||
|
||||
typedef struct VHDXMetadataEntries {
|
||||
VHDXMetadataTableEntry file_parameters_entry;
|
||||
VHDXMetadataTableEntry virtual_disk_size_entry;
|
||||
VHDXMetadataTableEntry page83_data_entry;
|
||||
VHDXMetadataTableEntry logical_sector_size_entry;
|
||||
VHDXMetadataTableEntry phys_sector_size_entry;
|
||||
VHDXMetadataTableEntry parent_locator_entry;
|
||||
uint16_t present;
|
||||
} VHDXMetadataEntries;
|
||||
|
||||
|
||||
typedef struct BDRVVHDXState {
|
||||
CoMutex lock;
|
||||
|
||||
int curr_header;
|
||||
VHDXHeader *headers[2];
|
||||
|
||||
VHDXRegionTableHeader rt;
|
||||
VHDXRegionTableEntry bat_rt; /* region table for the BAT */
|
||||
VHDXRegionTableEntry metadata_rt; /* region table for the metadata */
|
||||
|
||||
VHDXMetadataTableHeader metadata_hdr;
|
||||
VHDXMetadataEntries metadata_entries;
|
||||
|
||||
VHDXFileParameters params;
|
||||
uint32_t block_size;
|
||||
uint32_t block_size_bits;
|
||||
uint32_t sectors_per_block;
|
||||
uint32_t sectors_per_block_bits;
|
||||
|
||||
uint64_t virtual_disk_size;
|
||||
uint32_t logical_sector_size;
|
||||
uint32_t physical_sector_size;
|
||||
|
||||
uint64_t chunk_ratio;
|
||||
uint32_t chunk_ratio_bits;
|
||||
uint32_t logical_sector_size_bits;
|
||||
|
||||
uint32_t bat_entries;
|
||||
VHDXBatEntry *bat;
|
||||
uint64_t bat_offset;
|
||||
|
||||
VHDXParentLocatorHeader parent_header;
|
||||
VHDXParentLocatorEntry *parent_entries;
|
||||
|
||||
} BDRVVHDXState;
|
||||
|
||||
uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
|
||||
int crc_offset)
|
||||
{
|
||||
uint32_t crc_new;
|
||||
uint32_t crc_orig;
|
||||
assert(buf != NULL);
|
||||
|
||||
if (crc_offset > 0) {
|
||||
memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig));
|
||||
memset(buf + crc_offset, 0, sizeof(crc_orig));
|
||||
}
|
||||
|
||||
crc_new = crc32c(crc, buf, size);
|
||||
if (crc_offset > 0) {
|
||||
memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig));
|
||||
}
|
||||
|
||||
return crc_new;
|
||||
}
|
||||
|
||||
/* Validates the checksum of the buffer, with an in-place CRC.
|
||||
*
|
||||
* Zero is substituted during crc calculation for the original crc field,
|
||||
* and the crc field is restored afterwards. But the buffer will be modifed
|
||||
* during the calculation, so this may not be not suitable for multi-threaded
|
||||
* use.
|
||||
*
|
||||
* crc_offset: byte offset in buf of the buffer crc
|
||||
* buf: buffer pointer
|
||||
* size: size of buffer (must be > crc_offset+4)
|
||||
*
|
||||
* returns true if checksum is valid, false otherwise
|
||||
*/
|
||||
bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset)
|
||||
{
|
||||
uint32_t crc_orig;
|
||||
uint32_t crc;
|
||||
|
||||
assert(buf != NULL);
|
||||
assert(size > (crc_offset + 4));
|
||||
|
||||
memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig));
|
||||
crc_orig = le32_to_cpu(crc_orig);
|
||||
|
||||
crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset);
|
||||
|
||||
return crc == crc_orig;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Per the MS VHDX Specification, for every VHDX file:
|
||||
* - The header section is fixed size - 1 MB
|
||||
* - The header section is always the first "object"
|
||||
* - The first 64KB of the header is the File Identifier
|
||||
* - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile")
|
||||
* - The following 512 bytes constitute a UTF-16 string identifiying the
|
||||
* software that created the file, and is optional and diagnostic only.
|
||||
*
|
||||
* Therefore, we probe by looking for the vhdxfile signature "vhdxfile"
|
||||
*/
|
||||
static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename)
|
||||
{
|
||||
if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) {
|
||||
return 100;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* All VHDX structures on disk are little endian */
|
||||
static void vhdx_header_le_import(VHDXHeader *h)
|
||||
{
|
||||
assert(h != NULL);
|
||||
|
||||
le32_to_cpus(&h->signature);
|
||||
le32_to_cpus(&h->checksum);
|
||||
le64_to_cpus(&h->sequence_number);
|
||||
|
||||
leguid_to_cpus(&h->file_write_guid);
|
||||
leguid_to_cpus(&h->data_write_guid);
|
||||
leguid_to_cpus(&h->log_guid);
|
||||
|
||||
le16_to_cpus(&h->log_version);
|
||||
le16_to_cpus(&h->version);
|
||||
le32_to_cpus(&h->log_length);
|
||||
le64_to_cpus(&h->log_offset);
|
||||
}
|
||||
|
||||
|
||||
/* opens the specified header block from the VHDX file header section */
|
||||
static int vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s)
|
||||
{
|
||||
int ret = 0;
|
||||
VHDXHeader *header1;
|
||||
VHDXHeader *header2;
|
||||
bool h1_valid = false;
|
||||
bool h2_valid = false;
|
||||
uint64_t h1_seq = 0;
|
||||
uint64_t h2_seq = 0;
|
||||
uint8_t *buffer;
|
||||
|
||||
header1 = qemu_blockalign(bs, sizeof(VHDXHeader));
|
||||
header2 = qemu_blockalign(bs, sizeof(VHDXHeader));
|
||||
|
||||
buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE);
|
||||
|
||||
s->headers[0] = header1;
|
||||
s->headers[1] = header2;
|
||||
|
||||
/* We have to read the whole VHDX_HEADER_SIZE instead of
|
||||
* sizeof(VHDXHeader), because the checksum is over the whole
|
||||
* region */
|
||||
ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, VHDX_HEADER_SIZE);
|
||||
if (ret < 0) {
|
||||
goto fail;
|
||||
}
|
||||
/* copy over just the relevant portion that we need */
|
||||
memcpy(header1, buffer, sizeof(VHDXHeader));
|
||||
vhdx_header_le_import(header1);
|
||||
|
||||
if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) &&
|
||||
!memcmp(&header1->signature, "head", 4) &&
|
||||
header1->version == 1) {
|
||||
h1_seq = header1->sequence_number;
|
||||
h1_valid = true;
|
||||
}
|
||||
|
||||
ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE);
|
||||
if (ret < 0) {
|
||||
goto fail;
|
||||
}
|
||||
/* copy over just the relevant portion that we need */
|
||||
memcpy(header2, buffer, sizeof(VHDXHeader));
|
||||
vhdx_header_le_import(header2);
|
||||
|
||||
if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) &&
|
||||
!memcmp(&header2->signature, "head", 4) &&
|
||||
header2->version == 1) {
|
||||
h2_seq = header2->sequence_number;
|
||||
h2_valid = true;
|
||||
}
|
||||
|
||||
/* If there is only 1 valid header (or no valid headers), we
|
||||
* don't care what the sequence numbers are */
|
||||
if (h1_valid && !h2_valid) {
|
||||
s->curr_header = 0;
|
||||
} else if (!h1_valid && h2_valid) {
|
||||
s->curr_header = 1;
|
||||
} else if (!h1_valid && !h2_valid) {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
} else {
|
||||
/* If both headers are valid, then we choose the active one by the
|
||||
* highest sequence number. If the sequence numbers are equal, that is
|
||||
* invalid */
|
||||
if (h1_seq > h2_seq) {
|
||||
s->curr_header = 0;
|
||||
} else if (h2_seq > h1_seq) {
|
||||
s->curr_header = 1;
|
||||
} else {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
}
|
||||
|
||||
ret = 0;
|
||||
|
||||
goto exit;
|
||||
|
||||
fail:
|
||||
qerror_report(ERROR_CLASS_GENERIC_ERROR, "No valid VHDX header found");
|
||||
qemu_vfree(header1);
|
||||
qemu_vfree(header2);
|
||||
s->headers[0] = NULL;
|
||||
s->headers[1] = NULL;
|
||||
exit:
|
||||
qemu_vfree(buffer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s)
|
||||
{
|
||||
int ret = 0;
|
||||
uint8_t *buffer;
|
||||
int offset = 0;
|
||||
VHDXRegionTableEntry rt_entry;
|
||||
uint32_t i;
|
||||
bool bat_rt_found = false;
|
||||
bool metadata_rt_found = false;
|
||||
|
||||
/* We have to read the whole 64KB block, because the crc32 is over the
|
||||
* whole block */
|
||||
buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE);
|
||||
|
||||
ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer,
|
||||
VHDX_HEADER_BLOCK_SIZE);
|
||||
if (ret < 0) {
|
||||
goto fail;
|
||||
}
|
||||
memcpy(&s->rt, buffer, sizeof(s->rt));
|
||||
le32_to_cpus(&s->rt.signature);
|
||||
le32_to_cpus(&s->rt.checksum);
|
||||
le32_to_cpus(&s->rt.entry_count);
|
||||
le32_to_cpus(&s->rt.reserved);
|
||||
offset += sizeof(s->rt);
|
||||
|
||||
if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4) ||
|
||||
memcmp(&s->rt.signature, "regi", 4)) {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
|
||||
/* Per spec, maximum region table entry count is 2047 */
|
||||
if (s->rt.entry_count > 2047) {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
|
||||
for (i = 0; i < s->rt.entry_count; i++) {
|
||||
memcpy(&rt_entry, buffer + offset, sizeof(rt_entry));
|
||||
offset += sizeof(rt_entry);
|
||||
|
||||
leguid_to_cpus(&rt_entry.guid);
|
||||
le64_to_cpus(&rt_entry.file_offset);
|
||||
le32_to_cpus(&rt_entry.length);
|
||||
le32_to_cpus(&rt_entry.data_bits);
|
||||
|
||||
/* see if we recognize the entry */
|
||||
if (guid_eq(rt_entry.guid, bat_guid)) {
|
||||
/* must be unique; if we have already found it this is invalid */
|
||||
if (bat_rt_found) {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
bat_rt_found = true;
|
||||
s->bat_rt = rt_entry;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (guid_eq(rt_entry.guid, metadata_guid)) {
|
||||
/* must be unique; if we have already found it this is invalid */
|
||||
if (metadata_rt_found) {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
metadata_rt_found = true;
|
||||
s->metadata_rt = rt_entry;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) {
|
||||
/* cannot read vhdx file - required region table entry that
|
||||
* we do not understand. per spec, we must fail to open */
|
||||
ret = -ENOTSUP;
|
||||
goto fail;
|
||||
}
|
||||
}
|
||||
ret = 0;
|
||||
|
||||
fail:
|
||||
qemu_vfree(buffer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
|
||||
/* Metadata initial parser
|
||||
*
|
||||
* This loads all the metadata entry fields. This may cause additional
|
||||
* fields to be processed (e.g. parent locator, etc..).
|
||||
*
|
||||
* There are 5 Metadata items that are always required:
|
||||
* - File Parameters (block size, has a parent)
|
||||
* - Virtual Disk Size (size, in bytes, of the virtual drive)
|
||||
* - Page 83 Data (scsi page 83 guid)
|
||||
* - Logical Sector Size (logical sector size in bytes, either 512 or
|
||||
* 4096. We only support 512 currently)
|
||||
* - Physical Sector Size (512 or 4096)
|
||||
*
|
||||
* Also, if the File Parameters indicate this is a differencing file,
|
||||
* we must also look for the Parent Locator metadata item.
|
||||
*/
|
||||
static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s)
|
||||
{
|
||||
int ret = 0;
|
||||
uint8_t *buffer;
|
||||
int offset = 0;
|
||||
uint32_t i = 0;
|
||||
VHDXMetadataTableEntry md_entry;
|
||||
|
||||
buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE);
|
||||
|
||||
ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer,
|
||||
VHDX_METADATA_TABLE_MAX_SIZE);
|
||||
if (ret < 0) {
|
||||
goto exit;
|
||||
}
|
||||
memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr));
|
||||
offset += sizeof(s->metadata_hdr);
|
||||
|
||||
le64_to_cpus(&s->metadata_hdr.signature);
|
||||
le16_to_cpus(&s->metadata_hdr.reserved);
|
||||
le16_to_cpus(&s->metadata_hdr.entry_count);
|
||||
|
||||
if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
s->metadata_entries.present = 0;
|
||||
|
||||
if ((s->metadata_hdr.entry_count * sizeof(md_entry)) >
|
||||
(VHDX_METADATA_TABLE_MAX_SIZE - offset)) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
for (i = 0; i < s->metadata_hdr.entry_count; i++) {
|
||||
memcpy(&md_entry, buffer + offset, sizeof(md_entry));
|
||||
offset += sizeof(md_entry);
|
||||
|
||||
leguid_to_cpus(&md_entry.item_id);
|
||||
le32_to_cpus(&md_entry.offset);
|
||||
le32_to_cpus(&md_entry.length);
|
||||
le32_to_cpus(&md_entry.data_bits);
|
||||
le32_to_cpus(&md_entry.reserved2);
|
||||
|
||||
if (guid_eq(md_entry.item_id, file_param_guid)) {
|
||||
if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->metadata_entries.file_parameters_entry = md_entry;
|
||||
s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (guid_eq(md_entry.item_id, virtual_size_guid)) {
|
||||
if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->metadata_entries.virtual_disk_size_entry = md_entry;
|
||||
s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (guid_eq(md_entry.item_id, page83_guid)) {
|
||||
if (s->metadata_entries.present & META_PAGE_83_PRESENT) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->metadata_entries.page83_data_entry = md_entry;
|
||||
s->metadata_entries.present |= META_PAGE_83_PRESENT;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (guid_eq(md_entry.item_id, logical_sector_guid)) {
|
||||
if (s->metadata_entries.present &
|
||||
META_LOGICAL_SECTOR_SIZE_PRESENT) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->metadata_entries.logical_sector_size_entry = md_entry;
|
||||
s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (guid_eq(md_entry.item_id, phys_sector_guid)) {
|
||||
if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->metadata_entries.phys_sector_size_entry = md_entry;
|
||||
s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (guid_eq(md_entry.item_id, parent_locator_guid)) {
|
||||
if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->metadata_entries.parent_locator_entry = md_entry;
|
||||
s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) {
|
||||
/* cannot read vhdx file - required region table entry that
|
||||
* we do not understand. per spec, we must fail to open */
|
||||
ret = -ENOTSUP;
|
||||
goto exit;
|
||||
}
|
||||
}
|
||||
|
||||
if (s->metadata_entries.present != META_ALL_PRESENT) {
|
||||
ret = -ENOTSUP;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
ret = bdrv_pread(bs->file,
|
||||
s->metadata_entries.file_parameters_entry.offset
|
||||
+ s->metadata_rt.file_offset,
|
||||
&s->params,
|
||||
sizeof(s->params));
|
||||
|
||||
if (ret < 0) {
|
||||
goto exit;
|
||||
}
|
||||
|
||||
le32_to_cpus(&s->params.block_size);
|
||||
le32_to_cpus(&s->params.data_bits);
|
||||
|
||||
|
||||
/* We now have the file parameters, so we can tell if this is a
|
||||
* differencing file (i.e.. has_parent), is dynamic or fixed
|
||||
* sized (leave_blocks_allocated), and the block size */
|
||||
|
||||
/* The parent locator required iff the file parameters has_parent set */
|
||||
if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
|
||||
if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
|
||||
/* TODO: parse parent locator fields */
|
||||
ret = -ENOTSUP; /* temp, until differencing files are supported */
|
||||
goto exit;
|
||||
} else {
|
||||
/* if has_parent is set, but there is not parent locator present,
|
||||
* then that is an invalid combination */
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
}
|
||||
|
||||
/* determine virtual disk size, logical sector size,
|
||||
* and phys sector size */
|
||||
|
||||
ret = bdrv_pread(bs->file,
|
||||
s->metadata_entries.virtual_disk_size_entry.offset
|
||||
+ s->metadata_rt.file_offset,
|
||||
&s->virtual_disk_size,
|
||||
sizeof(uint64_t));
|
||||
if (ret < 0) {
|
||||
goto exit;
|
||||
}
|
||||
ret = bdrv_pread(bs->file,
|
||||
s->metadata_entries.logical_sector_size_entry.offset
|
||||
+ s->metadata_rt.file_offset,
|
||||
&s->logical_sector_size,
|
||||
sizeof(uint32_t));
|
||||
if (ret < 0) {
|
||||
goto exit;
|
||||
}
|
||||
ret = bdrv_pread(bs->file,
|
||||
s->metadata_entries.phys_sector_size_entry.offset
|
||||
+ s->metadata_rt.file_offset,
|
||||
&s->physical_sector_size,
|
||||
sizeof(uint32_t));
|
||||
if (ret < 0) {
|
||||
goto exit;
|
||||
}
|
||||
|
||||
le64_to_cpus(&s->virtual_disk_size);
|
||||
le32_to_cpus(&s->logical_sector_size);
|
||||
le32_to_cpus(&s->physical_sector_size);
|
||||
|
||||
if (s->logical_sector_size == 0 || s->params.block_size == 0) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
/* both block_size and sector_size are guaranteed powers of 2 */
|
||||
s->sectors_per_block = s->params.block_size / s->logical_sector_size;
|
||||
s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
|
||||
(uint64_t)s->logical_sector_size /
|
||||
(uint64_t)s->params.block_size;
|
||||
|
||||
/* These values are ones we will want to use for division / multiplication
|
||||
* later on, and they are all guaranteed (per the spec) to be powers of 2,
|
||||
* so we can take advantage of that for shift operations during
|
||||
* reads/writes */
|
||||
if (s->logical_sector_size & (s->logical_sector_size - 1)) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
if (s->sectors_per_block & (s->sectors_per_block - 1)) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
if (s->chunk_ratio & (s->chunk_ratio - 1)) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
s->block_size = s->params.block_size;
|
||||
if (s->block_size & (s->block_size - 1)) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size);
|
||||
s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block);
|
||||
s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio);
|
||||
s->block_size_bits = 31 - clz32(s->block_size);
|
||||
|
||||
ret = 0;
|
||||
|
||||
exit:
|
||||
qemu_vfree(buffer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Parse the replay log. Per the VHDX spec, if the log is present
|
||||
* it must be replayed prior to opening the file, even read-only.
|
||||
*
|
||||
* If read-only, we must replay the log in RAM (or refuse to open
|
||||
* a dirty VHDX file read-only */
|
||||
static int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s)
|
||||
{
|
||||
int ret = 0;
|
||||
int i;
|
||||
VHDXHeader *hdr;
|
||||
|
||||
hdr = s->headers[s->curr_header];
|
||||
|
||||
/* either the log guid, or log length is zero,
|
||||
* then a replay log is present */
|
||||
for (i = 0; i < sizeof(hdr->log_guid.data4); i++) {
|
||||
ret |= hdr->log_guid.data4[i];
|
||||
}
|
||||
if (hdr->log_guid.data1 == 0 &&
|
||||
hdr->log_guid.data2 == 0 &&
|
||||
hdr->log_guid.data3 == 0 &&
|
||||
ret == 0) {
|
||||
goto exit;
|
||||
}
|
||||
|
||||
/* per spec, only log version of 0 is supported */
|
||||
if (hdr->log_version != 0) {
|
||||
ret = -EINVAL;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
if (hdr->log_length == 0) {
|
||||
goto exit;
|
||||
}
|
||||
|
||||
/* We currently do not support images with logs to replay */
|
||||
ret = -ENOTSUP;
|
||||
|
||||
exit:
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
static int vhdx_open(BlockDriverState *bs, QDict *options, int flags)
|
||||
{
|
||||
BDRVVHDXState *s = bs->opaque;
|
||||
int ret = 0;
|
||||
uint32_t i;
|
||||
uint64_t signature;
|
||||
uint32_t data_blocks_cnt, bitmap_blocks_cnt;
|
||||
|
||||
|
||||
s->bat = NULL;
|
||||
|
||||
qemu_co_mutex_init(&s->lock);
|
||||
|
||||
/* validate the file signature */
|
||||
ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t));
|
||||
if (ret < 0) {
|
||||
goto fail;
|
||||
}
|
||||
if (memcmp(&signature, "vhdxfile", 8)) {
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
|
||||
ret = vhdx_parse_header(bs, s);
|
||||
if (ret) {
|
||||
goto fail;
|
||||
}
|
||||
|
||||
ret = vhdx_parse_log(bs, s);
|
||||
if (ret) {
|
||||
goto fail;
|
||||
}
|
||||
|
||||
ret = vhdx_open_region_tables(bs, s);
|
||||
if (ret) {
|
||||
goto fail;
|
||||
}
|
||||
|
||||
ret = vhdx_parse_metadata(bs, s);
|
||||
if (ret) {
|
||||
goto fail;
|
||||
}
|
||||
s->block_size = s->params.block_size;
|
||||
|
||||
/* the VHDX spec dictates that virtual_disk_size is always a multiple of
|
||||
* logical_sector_size */
|
||||
bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits;
|
||||
|
||||
data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits;
|
||||
if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) {
|
||||
data_blocks_cnt++;
|
||||
}
|
||||
bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits;
|
||||
if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) {
|
||||
bitmap_blocks_cnt++;
|
||||
}
|
||||
|
||||
if (s->parent_entries) {
|
||||
s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1);
|
||||
} else {
|
||||
s->bat_entries = data_blocks_cnt +
|
||||
((data_blocks_cnt - 1) >> s->chunk_ratio_bits);
|
||||
}
|
||||
|
||||
s->bat_offset = s->bat_rt.file_offset;
|
||||
|
||||
if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) {
|
||||
/* BAT allocation is not large enough for all entries */
|
||||
ret = -EINVAL;
|
||||
goto fail;
|
||||
}
|
||||
|
||||
s->bat = qemu_blockalign(bs, s->bat_rt.length);
|
||||
|
||||
ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length);
|
||||
if (ret < 0) {
|
||||
goto fail;
|
||||
}
|
||||
|
||||
for (i = 0; i < s->bat_entries; i++) {
|
||||
le64_to_cpus(&s->bat[i]);
|
||||
}
|
||||
|
||||
if (flags & BDRV_O_RDWR) {
|
||||
ret = -ENOTSUP;
|
||||
goto fail;
|
||||
}
|
||||
|
||||
/* TODO: differencing files, read, write */
|
||||
|
||||
return 0;
|
||||
fail:
|
||||
qemu_vfree(s->headers[0]);
|
||||
qemu_vfree(s->headers[1]);
|
||||
qemu_vfree(s->bat);
|
||||
qemu_vfree(s->parent_entries);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int vhdx_reopen_prepare(BDRVReopenState *state,
|
||||
BlockReopenQueue *queue, Error **errp)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num,
|
||||
int nb_sectors, QEMUIOVector *qiov)
|
||||
{
|
||||
return -ENOTSUP;
|
||||
}
|
||||
|
||||
|
||||
|
||||
static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,
|
||||
int nb_sectors, QEMUIOVector *qiov)
|
||||
{
|
||||
return -ENOTSUP;
|
||||
}
|
||||
|
||||
|
||||
static void vhdx_close(BlockDriverState *bs)
|
||||
{
|
||||
BDRVVHDXState *s = bs->opaque;
|
||||
qemu_vfree(s->headers[0]);
|
||||
qemu_vfree(s->headers[1]);
|
||||
qemu_vfree(s->bat);
|
||||
qemu_vfree(s->parent_entries);
|
||||
}
|
||||
|
||||
static BlockDriver bdrv_vhdx = {
|
||||
.format_name = "vhdx",
|
||||
.instance_size = sizeof(BDRVVHDXState),
|
||||
.bdrv_probe = vhdx_probe,
|
||||
.bdrv_open = vhdx_open,
|
||||
.bdrv_close = vhdx_close,
|
||||
.bdrv_reopen_prepare = vhdx_reopen_prepare,
|
||||
.bdrv_co_readv = vhdx_co_readv,
|
||||
.bdrv_co_writev = vhdx_co_writev,
|
||||
};
|
||||
|
||||
static void bdrv_vhdx_init(void)
|
||||
{
|
||||
bdrv_register(&bdrv_vhdx);
|
||||
}
|
||||
|
||||
block_init(bdrv_vhdx_init);
|
||||
14
block/vhdx.h
14
block/vhdx.h
@ -308,4 +308,18 @@ typedef struct QEMU_PACKED VHDXParentLocatorEntry {
|
||||
|
||||
/* ----- END VHDX SPECIFICATION STRUCTURES ---- */
|
||||
|
||||
|
||||
uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
|
||||
int crc_offset);
|
||||
|
||||
bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset);
|
||||
|
||||
|
||||
static void leguid_to_cpus(MSGUID *guid)
|
||||
{
|
||||
le32_to_cpus(&guid->data1);
|
||||
le16_to_cpus(&guid->data2);
|
||||
le16_to_cpus(&guid->data3);
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user