Browse Source
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>
stable-1.5
Jeff Cody
14 years ago
committed by
Stefan Hajnoczi
Stefan Hajnoczi
3 changed files with 868 additions and 0 deletions
@ -0,0 +1,853 @@ |
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/*
|
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* Block driver for Hyper-V VHDX Images |
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* |
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* Copyright (c) 2013 Red Hat, Inc., |
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* |
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* Authors: |
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* Jeff Cody <jcody@redhat.com> |
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* |
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* This is based on the "VHDX Format Specification v0.95", published 4/12/2012 |
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* by Microsoft: |
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* https://www.microsoft.com/en-us/download/details.aspx?id=29681
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* |
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* This work is licensed under the terms of the GNU LGPL, version 2 or later. |
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* See the COPYING.LIB file in the top-level directory. |
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* |
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*/ |
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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 "qemu/crc32c.h" |
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#include "block/vhdx.h" |
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/* Several metadata and region table data entries are identified by
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* guids in a MS-specific GUID format. */ |
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/* ------- Known Region Table GUIDs ---------------------- */ |
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static const MSGUID bat_guid = { .data1 = 0x2dc27766, |
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.data2 = 0xf623, |
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.data3 = 0x4200, |
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.data4 = { 0x9d, 0x64, 0x11, 0x5e, |
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0x9b, 0xfd, 0x4a, 0x08} }; |
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static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, |
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.data2 = 0x4790, |
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.data3 = 0x4b9a, |
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.data4 = { 0xb8, 0xfe, 0x57, 0x5f, |
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0x05, 0x0f, 0x88, 0x6e} }; |
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/* ------- Known Metadata Entry GUIDs ---------------------- */ |
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static const MSGUID file_param_guid = { .data1 = 0xcaa16737, |
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.data2 = 0xfa36, |
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.data3 = 0x4d43, |
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.data4 = { 0xb3, 0xb6, 0x33, 0xf0, |
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0xaa, 0x44, 0xe7, 0x6b} }; |
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static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, |
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.data2 = 0xcd1b, |
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.data3 = 0x4876, |
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.data4 = { 0xb2, 0x11, 0x5d, 0xbe, |
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0xd8, 0x3b, 0xf4, 0xb8} }; |
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|
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static const MSGUID page83_guid = { .data1 = 0xbeca12ab, |
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.data2 = 0xb2e6, |
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.data3 = 0x4523, |
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.data4 = { 0x93, 0xef, 0xc3, 0x09, |
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0xe0, 0x00, 0xc7, 0x46} }; |
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static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, |
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.data2 = 0x445d, |
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.data3 = 0x4471, |
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.data4 = { 0x9c, 0xc9, 0xe9, 0x88, |
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0x52, 0x51, 0xc5, 0x56} }; |
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static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, |
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.data2 = 0xb30b, |
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.data3 = 0x454d, |
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.data4 = { 0xab, 0xf7, 0xd3, |
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0xd8, 0x48, 0x34, |
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0xab, 0x0c} }; |
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static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, |
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.data2 = 0xa96f, |
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.data3 = 0x4709, |
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.data4 = { 0xba, 0x47, 0xf2, |
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0x33, 0xa8, 0xfa, |
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0xab, 0x5f} }; |
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/* Each parent type must have a valid GUID; this is for parent images
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* of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would |
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* need to make up our own QCOW2 GUID type */ |
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static const MSGUID parent_vhdx_guid = { .data1 = 0xb04aefb7, |
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.data2 = 0xd19e, |
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.data3 = 0x4a81, |
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.data4 = { 0xb7, 0x89, 0x25, 0xb8, |
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0xe9, 0x44, 0x59, 0x13} }; |
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#define META_FILE_PARAMETER_PRESENT 0x01 |
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#define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 |
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#define META_PAGE_83_PRESENT 0x04 |
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#define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 |
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#define META_PHYS_SECTOR_SIZE_PRESENT 0x10 |
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#define META_PARENT_LOCATOR_PRESENT 0x20 |
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#define META_ALL_PRESENT \ |
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(META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ |
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META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ |
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META_PHYS_SECTOR_SIZE_PRESENT) |
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typedef struct VHDXMetadataEntries { |
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VHDXMetadataTableEntry file_parameters_entry; |
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VHDXMetadataTableEntry virtual_disk_size_entry; |
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VHDXMetadataTableEntry page83_data_entry; |
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VHDXMetadataTableEntry logical_sector_size_entry; |
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VHDXMetadataTableEntry phys_sector_size_entry; |
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VHDXMetadataTableEntry parent_locator_entry; |
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uint16_t present; |
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} VHDXMetadataEntries; |
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typedef struct BDRVVHDXState { |
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CoMutex lock; |
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int curr_header; |
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VHDXHeader *headers[2]; |
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VHDXRegionTableHeader rt; |
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VHDXRegionTableEntry bat_rt; /* region table for the BAT */ |
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VHDXRegionTableEntry metadata_rt; /* region table for the metadata */ |
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VHDXMetadataTableHeader metadata_hdr; |
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VHDXMetadataEntries metadata_entries; |
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VHDXFileParameters params; |
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uint32_t block_size; |
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uint32_t block_size_bits; |
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uint32_t sectors_per_block; |
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uint32_t sectors_per_block_bits; |
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uint64_t virtual_disk_size; |
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uint32_t logical_sector_size; |
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uint32_t physical_sector_size; |
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uint64_t chunk_ratio; |
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uint32_t chunk_ratio_bits; |
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uint32_t logical_sector_size_bits; |
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uint32_t bat_entries; |
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VHDXBatEntry *bat; |
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uint64_t bat_offset; |
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VHDXParentLocatorHeader parent_header; |
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VHDXParentLocatorEntry *parent_entries; |
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} BDRVVHDXState; |
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uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, |
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int crc_offset) |
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{ |
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uint32_t crc_new; |
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uint32_t crc_orig; |
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assert(buf != NULL); |
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if (crc_offset > 0) { |
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memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); |
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memset(buf + crc_offset, 0, sizeof(crc_orig)); |
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} |
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crc_new = crc32c(crc, buf, size); |
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if (crc_offset > 0) { |
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memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); |
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} |
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return crc_new; |
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} |
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/* Validates the checksum of the buffer, with an in-place CRC.
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* |
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* Zero is substituted during crc calculation for the original crc field, |
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* and the crc field is restored afterwards. But the buffer will be modifed |
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* during the calculation, so this may not be not suitable for multi-threaded |
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* use. |
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* |
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* crc_offset: byte offset in buf of the buffer crc |
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* buf: buffer pointer |
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* size: size of buffer (must be > crc_offset+4) |
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* |
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* returns true if checksum is valid, false otherwise |
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*/ |
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bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) |
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{ |
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uint32_t crc_orig; |
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uint32_t crc; |
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assert(buf != NULL); |
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assert(size > (crc_offset + 4)); |
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memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); |
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crc_orig = le32_to_cpu(crc_orig); |
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crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); |
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return crc == crc_orig; |
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} |
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/*
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* Per the MS VHDX Specification, for every VHDX file: |
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* - The header section is fixed size - 1 MB |
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* - The header section is always the first "object" |
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* - The first 64KB of the header is the File Identifier |
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* - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") |
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* - The following 512 bytes constitute a UTF-16 string identifiying the |
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* software that created the file, and is optional and diagnostic only. |
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* |
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* Therefore, we probe by looking for the vhdxfile signature "vhdxfile" |
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*/ |
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static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { |
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return 100; |
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} |
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return 0; |
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} |
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/* All VHDX structures on disk are little endian */ |
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static void vhdx_header_le_import(VHDXHeader *h) |
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{ |
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assert(h != NULL); |
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le32_to_cpus(&h->signature); |
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le32_to_cpus(&h->checksum); |
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le64_to_cpus(&h->sequence_number); |
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leguid_to_cpus(&h->file_write_guid); |
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leguid_to_cpus(&h->data_write_guid); |
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leguid_to_cpus(&h->log_guid); |
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le16_to_cpus(&h->log_version); |
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le16_to_cpus(&h->version); |
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le32_to_cpus(&h->log_length); |
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le64_to_cpus(&h->log_offset); |
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} |
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/* opens the specified header block from the VHDX file header section */ |
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static int vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s) |
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{ |
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int ret = 0; |
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VHDXHeader *header1; |
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VHDXHeader *header2; |
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bool h1_valid = false; |
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bool h2_valid = false; |
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uint64_t h1_seq = 0; |
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uint64_t h2_seq = 0; |
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uint8_t *buffer; |
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header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); |
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header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); |
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buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); |
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s->headers[0] = header1; |
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s->headers[1] = header2; |
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/* We have to read the whole VHDX_HEADER_SIZE instead of
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* sizeof(VHDXHeader), because the checksum is over the whole |
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* region */ |
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ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, VHDX_HEADER_SIZE); |
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if (ret < 0) { |
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goto fail; |
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} |
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/* copy over just the relevant portion that we need */ |
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memcpy(header1, buffer, sizeof(VHDXHeader)); |
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vhdx_header_le_import(header1); |
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if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) && |
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!memcmp(&header1->signature, "head", 4) && |
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header1->version == 1) { |
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h1_seq = header1->sequence_number; |
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h1_valid = true; |
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} |
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ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE); |
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if (ret < 0) { |
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goto fail; |
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} |
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/* copy over just the relevant portion that we need */ |
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memcpy(header2, buffer, sizeof(VHDXHeader)); |
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vhdx_header_le_import(header2); |
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if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) && |
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!memcmp(&header2->signature, "head", 4) && |
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header2->version == 1) { |
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h2_seq = header2->sequence_number; |
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h2_valid = true; |
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} |
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/* If there is only 1 valid header (or no valid headers), we
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* don't care what the sequence numbers are */ |
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if (h1_valid && !h2_valid) { |
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s->curr_header = 0; |
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} else if (!h1_valid && h2_valid) { |
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s->curr_header = 1; |
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} else if (!h1_valid && !h2_valid) { |
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ret = -EINVAL; |
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goto fail; |
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} else { |
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/* If both headers are valid, then we choose the active one by the
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* highest sequence number. If the sequence numbers are equal, that is |
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* invalid */ |
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if (h1_seq > h2_seq) { |
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s->curr_header = 0; |
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} else if (h2_seq > h1_seq) { |
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s->curr_header = 1; |
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} else { |
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ret = -EINVAL; |
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goto fail; |
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} |
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} |
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ret = 0; |
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goto exit; |
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fail: |
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qerror_report(ERROR_CLASS_GENERIC_ERROR, "No valid VHDX header found"); |
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qemu_vfree(header1); |
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qemu_vfree(header2); |
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s->headers[0] = NULL; |
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s->headers[1] = NULL; |
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exit: |
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qemu_vfree(buffer); |
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return ret; |
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} |
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static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) |
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{ |
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int ret = 0; |
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uint8_t *buffer; |
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int offset = 0; |
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VHDXRegionTableEntry rt_entry; |
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uint32_t i; |
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bool bat_rt_found = false; |
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bool metadata_rt_found = false; |
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/* We have to read the whole 64KB block, because the crc32 is over the
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* whole block */ |
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buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); |
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ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, |
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VHDX_HEADER_BLOCK_SIZE); |
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if (ret < 0) { |
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goto fail; |
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} |
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memcpy(&s->rt, buffer, sizeof(s->rt)); |
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le32_to_cpus(&s->rt.signature); |
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le32_to_cpus(&s->rt.checksum); |
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le32_to_cpus(&s->rt.entry_count); |
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le32_to_cpus(&s->rt.reserved); |
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offset += sizeof(s->rt); |
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if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4) || |
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memcmp(&s->rt.signature, "regi", 4)) { |
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ret = -EINVAL; |
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goto fail; |
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} |
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/* Per spec, maximum region table entry count is 2047 */ |
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if (s->rt.entry_count > 2047) { |
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ret = -EINVAL; |
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goto fail; |
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} |
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for (i = 0; i < s->rt.entry_count; i++) { |
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memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); |
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offset += sizeof(rt_entry); |
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leguid_to_cpus(&rt_entry.guid); |
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le64_to_cpus(&rt_entry.file_offset); |
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le32_to_cpus(&rt_entry.length); |
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le32_to_cpus(&rt_entry.data_bits); |
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/* see if we recognize the entry */ |
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if (guid_eq(rt_entry.guid, bat_guid)) { |
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/* must be unique; if we have already found it this is invalid */ |
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if (bat_rt_found) { |
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ret = -EINVAL; |
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goto fail; |
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} |
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bat_rt_found = true; |
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s->bat_rt = rt_entry; |
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continue; |
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} |
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if (guid_eq(rt_entry.guid, metadata_guid)) { |
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/* must be unique; if we have already found it this is invalid */ |
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if (metadata_rt_found) { |
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ret = -EINVAL; |
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goto fail; |
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} |
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metadata_rt_found = true; |
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s->metadata_rt = rt_entry; |
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continue; |
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} |
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|
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if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { |
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/* cannot read vhdx file - required region table entry that
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* we do not understand. per spec, we must fail to open */ |
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ret = -ENOTSUP; |
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goto fail; |
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} |
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} |
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ret = 0; |
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fail: |
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qemu_vfree(buffer); |
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return ret; |
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} |
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|
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|
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|
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/* Metadata initial parser
|
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* |
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* This loads all the metadata entry fields. This may cause additional |
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* fields to be processed (e.g. parent locator, etc..). |
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* |
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* There are 5 Metadata items that are always required: |
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* - File Parameters (block size, has a parent) |
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* - Virtual Disk Size (size, in bytes, of the virtual drive) |
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* - Page 83 Data (scsi page 83 guid) |
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* - Logical Sector Size (logical sector size in bytes, either 512 or |
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* 4096. We only support 512 currently) |
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* - Physical Sector Size (512 or 4096) |
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* |
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* Also, if the File Parameters indicate this is a differencing file, |
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* we must also look for the Parent Locator metadata item. |
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*/ |
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static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) |
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{ |
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int ret = 0; |
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uint8_t *buffer; |
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int offset = 0; |
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uint32_t i = 0; |
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VHDXMetadataTableEntry md_entry; |
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|
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buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); |
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|
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ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, |
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VHDX_METADATA_TABLE_MAX_SIZE); |
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if (ret < 0) { |
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goto exit; |
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} |
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memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); |
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offset += sizeof(s->metadata_hdr); |
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|
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le64_to_cpus(&s->metadata_hdr.signature); |
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le16_to_cpus(&s->metadata_hdr.reserved); |
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le16_to_cpus(&s->metadata_hdr.entry_count); |
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|
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if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) { |
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ret = -EINVAL; |
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goto exit; |
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} |
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|
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s->metadata_entries.present = 0; |
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|
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if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > |
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(VHDX_METADATA_TABLE_MAX_SIZE - offset)) { |
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ret = -EINVAL; |
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goto exit; |
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} |
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|
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for (i = 0; i < s->metadata_hdr.entry_count; i++) { |
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memcpy(&md_entry, buffer + offset, sizeof(md_entry)); |
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offset += sizeof(md_entry); |
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|
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leguid_to_cpus(&md_entry.item_id); |
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le32_to_cpus(&md_entry.offset); |
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le32_to_cpus(&md_entry.length); |
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le32_to_cpus(&md_entry.data_bits); |
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le32_to_cpus(&md_entry.reserved2); |
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|
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if (guid_eq(md_entry.item_id, file_param_guid)) { |
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if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { |
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ret = -EINVAL; |
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goto exit; |
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} |
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s->metadata_entries.file_parameters_entry = md_entry; |
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s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; |
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continue; |
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} |
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|
|||
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); |
|||
Loading…
Reference in new issue