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-rw-r--r--qemu/block/vpc.c944
1 files changed, 944 insertions, 0 deletions
diff --git a/qemu/block/vpc.c b/qemu/block/vpc.c
new file mode 100644
index 000000000..3e385d9fb
--- /dev/null
+++ b/qemu/block/vpc.c
@@ -0,0 +1,944 @@
+/*
+ * Block driver for Connectix / Microsoft Virtual PC images
+ *
+ * Copyright (c) 2005 Alex Beregszaszi
+ * Copyright (c) 2009 Kevin Wolf <kwolf@suse.de>
+ *
+ * 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/block_int.h"
+#include "qemu/module.h"
+#include "migration/migration.h"
+#if defined(CONFIG_UUID)
+#include <uuid/uuid.h>
+#endif
+
+/**************************************************************/
+
+#define HEADER_SIZE 512
+
+//#define CACHE
+
+enum vhd_type {
+ VHD_FIXED = 2,
+ VHD_DYNAMIC = 3,
+ VHD_DIFFERENCING = 4,
+};
+
+// Seconds since Jan 1, 2000 0:00:00 (UTC)
+#define VHD_TIMESTAMP_BASE 946684800
+
+#define VHD_MAX_SECTORS (65535LL * 255 * 255)
+#define VHD_MAX_GEOMETRY (65535LL * 16 * 255)
+
+// always big-endian
+typedef struct vhd_footer {
+ char creator[8]; // "conectix"
+ uint32_t features;
+ uint32_t version;
+
+ // Offset of next header structure, 0xFFFFFFFF if none
+ uint64_t data_offset;
+
+ // Seconds since Jan 1, 2000 0:00:00 (UTC)
+ uint32_t timestamp;
+
+ char creator_app[4]; // "vpc "
+ uint16_t major;
+ uint16_t minor;
+ char creator_os[4]; // "Wi2k"
+
+ uint64_t orig_size;
+ uint64_t current_size;
+
+ uint16_t cyls;
+ uint8_t heads;
+ uint8_t secs_per_cyl;
+
+ uint32_t type;
+
+ // Checksum of the Hard Disk Footer ("one's complement of the sum of all
+ // the bytes in the footer without the checksum field")
+ uint32_t checksum;
+
+ // UUID used to identify a parent hard disk (backing file)
+ uint8_t uuid[16];
+
+ uint8_t in_saved_state;
+} QEMU_PACKED VHDFooter;
+
+typedef struct vhd_dyndisk_header {
+ char magic[8]; // "cxsparse"
+
+ // Offset of next header structure, 0xFFFFFFFF if none
+ uint64_t data_offset;
+
+ // Offset of the Block Allocation Table (BAT)
+ uint64_t table_offset;
+
+ uint32_t version;
+ uint32_t max_table_entries; // 32bit/entry
+
+ // 2 MB by default, must be a power of two
+ uint32_t block_size;
+
+ uint32_t checksum;
+ uint8_t parent_uuid[16];
+ uint32_t parent_timestamp;
+ uint32_t reserved;
+
+ // Backing file name (in UTF-16)
+ uint8_t parent_name[512];
+
+ struct {
+ uint32_t platform;
+ uint32_t data_space;
+ uint32_t data_length;
+ uint32_t reserved;
+ uint64_t data_offset;
+ } parent_locator[8];
+} QEMU_PACKED VHDDynDiskHeader;
+
+typedef struct BDRVVPCState {
+ CoMutex lock;
+ uint8_t footer_buf[HEADER_SIZE];
+ uint64_t free_data_block_offset;
+ int max_table_entries;
+ uint32_t *pagetable;
+ uint64_t bat_offset;
+ uint64_t last_bitmap_offset;
+
+ uint32_t block_size;
+ uint32_t bitmap_size;
+
+#ifdef CACHE
+ uint8_t *pageentry_u8;
+ uint32_t *pageentry_u32;
+ uint16_t *pageentry_u16;
+
+ uint64_t last_bitmap;
+#endif
+
+ Error *migration_blocker;
+} BDRVVPCState;
+
+static uint32_t vpc_checksum(uint8_t* buf, size_t size)
+{
+ uint32_t res = 0;
+ int i;
+
+ for (i = 0; i < size; i++)
+ res += buf[i];
+
+ return ~res;
+}
+
+
+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, QDict *options, int flags,
+ Error **errp)
+{
+ BDRVVPCState *s = bs->opaque;
+ int i;
+ VHDFooter *footer;
+ VHDDynDiskHeader *dyndisk_header;
+ uint8_t buf[HEADER_SIZE];
+ uint32_t checksum;
+ uint64_t computed_size;
+ uint64_t pagetable_size;
+ int disk_type = VHD_DYNAMIC;
+ int ret;
+
+ ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ footer = (VHDFooter *) s->footer_buf;
+ if (strncmp(footer->creator, "conectix", 8)) {
+ int64_t offset = bdrv_getlength(bs->file);
+ if (offset < 0) {
+ ret = offset;
+ goto fail;
+ } else if (offset < HEADER_SIZE) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* If a fixed disk, the footer is found only at the end of the file */
+ ret = bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf,
+ HEADER_SIZE);
+ if (ret < 0) {
+ goto fail;
+ }
+ if (strncmp(footer->creator, "conectix", 8)) {
+ error_setg(errp, "invalid VPC image");
+ ret = -EINVAL;
+ goto fail;
+ }
+ disk_type = VHD_FIXED;
+ }
+
+ checksum = be32_to_cpu(footer->checksum);
+ footer->checksum = 0;
+ if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum)
+ fprintf(stderr, "block-vpc: The header checksum of '%s' is "
+ "incorrect.\n", bs->filename);
+
+ /* Write 'checksum' back to footer, or else will leave it with zero. */
+ footer->checksum = cpu_to_be32(checksum);
+
+ // The visible size of a image in Virtual PC depends on the geometry
+ // rather than on the size stored in the footer (the size in the footer
+ // is too large usually)
+ bs->total_sectors = (int64_t)
+ be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
+
+ /* Images that have exactly the maximum geometry are probably bigger and
+ * would be truncated if we adhered to the geometry for them. Rely on
+ * footer->current_size for them. */
+ if (bs->total_sectors == VHD_MAX_GEOMETRY) {
+ bs->total_sectors = be64_to_cpu(footer->current_size) /
+ BDRV_SECTOR_SIZE;
+ }
+
+ /* Allow a maximum disk size of approximately 2 TB */
+ if (bs->total_sectors >= VHD_MAX_SECTORS) {
+ ret = -EFBIG;
+ goto fail;
+ }
+
+ if (disk_type == VHD_DYNAMIC) {
+ ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf,
+ HEADER_SIZE);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ dyndisk_header = (VHDDynDiskHeader *) buf;
+
+ if (strncmp(dyndisk_header->magic, "cxsparse", 8)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ s->block_size = be32_to_cpu(dyndisk_header->block_size);
+ if (!is_power_of_2(s->block_size) || s->block_size < BDRV_SECTOR_SIZE) {
+ error_setg(errp, "Invalid block size %" PRIu32, s->block_size);
+ ret = -EINVAL;
+ goto fail;
+ }
+ s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511;
+
+ s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
+
+ if ((bs->total_sectors * 512) / s->block_size > 0xffffffffU) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (s->max_table_entries > (VHD_MAX_SECTORS * 512) / s->block_size) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ computed_size = (uint64_t) s->max_table_entries * s->block_size;
+ if (computed_size < bs->total_sectors * 512) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (s->max_table_entries > SIZE_MAX / 4 ||
+ s->max_table_entries > (int) INT_MAX / 4) {
+ error_setg(errp, "Max Table Entries too large (%" PRId32 ")",
+ s->max_table_entries);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ pagetable_size = (uint64_t) s->max_table_entries * 4;
+
+ s->pagetable = qemu_try_blockalign(bs->file, pagetable_size);
+ if (s->pagetable == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
+
+ ret = bdrv_pread(bs->file, s->bat_offset, s->pagetable, pagetable_size);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ s->free_data_block_offset =
+ ROUND_UP(s->bat_offset + pagetable_size, 512);
+
+ for (i = 0; i < s->max_table_entries; i++) {
+ be32_to_cpus(&s->pagetable[i]);
+ if (s->pagetable[i] != 0xFFFFFFFF) {
+ int64_t next = (512 * (int64_t) s->pagetable[i]) +
+ s->bitmap_size + s->block_size;
+
+ if (next > s->free_data_block_offset) {
+ s->free_data_block_offset = next;
+ }
+ }
+ }
+
+ if (s->free_data_block_offset > bdrv_getlength(bs->file)) {
+ error_setg(errp, "block-vpc: free_data_block_offset points after "
+ "the end of file. The image has been truncated.");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ s->last_bitmap_offset = (int64_t) -1;
+
+#ifdef CACHE
+ s->pageentry_u8 = g_malloc(512);
+ s->pageentry_u32 = s->pageentry_u8;
+ s->pageentry_u16 = s->pageentry_u8;
+ s->last_pagetable = -1;
+#endif
+ }
+
+ qemu_co_mutex_init(&s->lock);
+
+ /* Disable migration when VHD images are used */
+ error_setg(&s->migration_blocker, "The vpc format used by node '%s' "
+ "does not support live migration",
+ bdrv_get_device_or_node_name(bs));
+ migrate_add_blocker(s->migration_blocker);
+
+ return 0;
+
+fail:
+ qemu_vfree(s->pagetable);
+#ifdef CACHE
+ g_free(s->pageentry_u8);
+#endif
+ return ret;
+}
+
+static int vpc_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ return 0;
+}
+
+/*
+ * Returns the absolute byte offset of the given sector in the image file.
+ * If the sector is not allocated, -1 is returned instead.
+ *
+ * The parameter write must be 1 if the offset will be used for a write
+ * operation (the block bitmaps is updated then), 0 otherwise.
+ */
+static inline int64_t get_sector_offset(BlockDriverState *bs,
+ int64_t sector_num, int write)
+{
+ 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->block_size;
+ pageentry_index = (offset % s->block_size) / 512;
+
+ if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff)
+ return -1; // not allocated
+
+ bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index];
+ block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index);
+
+ // We must ensure that we don't write to any sectors which are marked as
+ // unused in the bitmap. We get away with setting all bits in the block
+ // bitmap each time we write to a new block. This might cause Virtual PC to
+ // miss sparse read optimization, but it's not a problem in terms of
+ // correctness.
+ if (write && (s->last_bitmap_offset != bitmap_offset)) {
+ uint8_t bitmap[s->bitmap_size];
+
+ s->last_bitmap_offset = bitmap_offset;
+ memset(bitmap, 0xff, s->bitmap_size);
+ bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size);
+ }
+
+ return block_offset;
+}
+
+/*
+ * Writes the footer to the end of the image file. This is needed when the
+ * file grows as it overwrites the old footer
+ *
+ * Returns 0 on success and < 0 on error
+ */
+static int rewrite_footer(BlockDriverState* bs)
+{
+ int ret;
+ BDRVVPCState *s = bs->opaque;
+ int64_t offset = s->free_data_block_offset;
+
+ ret = bdrv_pwrite_sync(bs->file, offset, s->footer_buf, HEADER_SIZE);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Allocates a new block. This involves writing a new footer and updating
+ * the Block Allocation Table to use the space at the old end of the image
+ * file (overwriting the old footer)
+ *
+ * Returns the sectors' offset in the image file on success and < 0 on error
+ */
+static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
+{
+ BDRVVPCState *s = bs->opaque;
+ int64_t bat_offset;
+ uint32_t index, bat_value;
+ int ret;
+ uint8_t bitmap[s->bitmap_size];
+
+ // Check if sector_num is valid
+ if ((sector_num < 0) || (sector_num > bs->total_sectors))
+ return -1;
+
+ // Write entry into in-memory BAT
+ index = (sector_num * 512) / s->block_size;
+ if (s->pagetable[index] != 0xFFFFFFFF)
+ return -1;
+
+ s->pagetable[index] = s->free_data_block_offset / 512;
+
+ // Initialize the block's bitmap
+ memset(bitmap, 0xff, s->bitmap_size);
+ ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap,
+ s->bitmap_size);
+ if (ret < 0) {
+ return ret;
+ }
+
+ // Write new footer (the old one will be overwritten)
+ s->free_data_block_offset += s->block_size + s->bitmap_size;
+ ret = rewrite_footer(bs);
+ if (ret < 0)
+ goto fail;
+
+ // Write BAT entry to disk
+ bat_offset = s->bat_offset + (4 * index);
+ bat_value = cpu_to_be32(s->pagetable[index]);
+ ret = bdrv_pwrite_sync(bs->file, bat_offset, &bat_value, 4);
+ if (ret < 0)
+ goto fail;
+
+ return get_sector_offset(bs, sector_num, 0);
+
+fail:
+ s->free_data_block_offset -= (s->block_size + s->bitmap_size);
+ return -1;
+}
+
+static int vpc_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+ BDRVVPCState *s = (BDRVVPCState *)bs->opaque;
+ VHDFooter *footer = (VHDFooter *) s->footer_buf;
+
+ if (be32_to_cpu(footer->type) != VHD_FIXED) {
+ bdi->cluster_size = s->block_size;
+ }
+
+ bdi->unallocated_blocks_are_zero = true;
+ return 0;
+}
+
+static int vpc_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ BDRVVPCState *s = bs->opaque;
+ int ret;
+ int64_t offset;
+ int64_t sectors, sectors_per_block;
+ VHDFooter *footer = (VHDFooter *) s->footer_buf;
+
+ if (be32_to_cpu(footer->type) == VHD_FIXED) {
+ return bdrv_read(bs->file, sector_num, buf, nb_sectors);
+ }
+ while (nb_sectors > 0) {
+ offset = get_sector_offset(bs, sector_num, 0);
+
+ sectors_per_block = s->block_size >> BDRV_SECTOR_BITS;
+ sectors = sectors_per_block - (sector_num % sectors_per_block);
+ if (sectors > nb_sectors) {
+ sectors = nb_sectors;
+ }
+
+ if (offset == -1) {
+ memset(buf, 0, sectors * BDRV_SECTOR_SIZE);
+ } else {
+ ret = bdrv_pread(bs->file, offset, buf,
+ sectors * BDRV_SECTOR_SIZE);
+ if (ret != sectors * BDRV_SECTOR_SIZE) {
+ return -1;
+ }
+ }
+
+ nb_sectors -= sectors;
+ sector_num += sectors;
+ buf += sectors * BDRV_SECTOR_SIZE;
+ }
+ return 0;
+}
+
+static coroutine_fn int vpc_co_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ int ret;
+ BDRVVPCState *s = bs->opaque;
+ qemu_co_mutex_lock(&s->lock);
+ ret = vpc_read(bs, sector_num, buf, nb_sectors);
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+static int vpc_write(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
+{
+ BDRVVPCState *s = bs->opaque;
+ int64_t offset;
+ int64_t sectors, sectors_per_block;
+ int ret;
+ VHDFooter *footer = (VHDFooter *) s->footer_buf;
+
+ if (be32_to_cpu(footer->type) == VHD_FIXED) {
+ return bdrv_write(bs->file, sector_num, buf, nb_sectors);
+ }
+ while (nb_sectors > 0) {
+ offset = get_sector_offset(bs, sector_num, 1);
+
+ sectors_per_block = s->block_size >> BDRV_SECTOR_BITS;
+ sectors = sectors_per_block - (sector_num % sectors_per_block);
+ if (sectors > nb_sectors) {
+ sectors = nb_sectors;
+ }
+
+ if (offset == -1) {
+ offset = alloc_block(bs, sector_num);
+ if (offset < 0)
+ return -1;
+ }
+
+ ret = bdrv_pwrite(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE);
+ if (ret != sectors * BDRV_SECTOR_SIZE) {
+ return -1;
+ }
+
+ nb_sectors -= sectors;
+ sector_num += sectors;
+ buf += sectors * BDRV_SECTOR_SIZE;
+ }
+
+ return 0;
+}
+
+static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
+{
+ int ret;
+ BDRVVPCState *s = bs->opaque;
+ qemu_co_mutex_lock(&s->lock);
+ ret = vpc_write(bs, sector_num, buf, nb_sectors);
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, int *pnum)
+{
+ BDRVVPCState *s = bs->opaque;
+ VHDFooter *footer = (VHDFooter*) s->footer_buf;
+ int64_t start, offset;
+ bool allocated;
+ int n;
+
+ if (be32_to_cpu(footer->type) == VHD_FIXED) {
+ *pnum = nb_sectors;
+ return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
+ (sector_num << BDRV_SECTOR_BITS);
+ }
+
+ offset = get_sector_offset(bs, sector_num, 0);
+ start = offset;
+ allocated = (offset != -1);
+ *pnum = 0;
+
+ do {
+ /* All sectors in a block are contiguous (without using the bitmap) */
+ n = ROUND_UP(sector_num + 1, s->block_size / BDRV_SECTOR_SIZE)
+ - sector_num;
+ n = MIN(n, nb_sectors);
+
+ *pnum += n;
+ sector_num += n;
+ nb_sectors -= n;
+ /* *pnum can't be greater than one block for allocated
+ * sectors since there is always a bitmap in between. */
+ if (allocated) {
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+ }
+ if (nb_sectors == 0) {
+ break;
+ }
+ offset = get_sector_offset(bs, sector_num, 0);
+ } while (offset == -1);
+
+ return 0;
+}
+
+/*
+ * Calculates the number of cylinders, heads and sectors per cylinder
+ * based on a given number of sectors. This is the algorithm described
+ * in the VHD specification.
+ *
+ * Note that the geometry doesn't always exactly match total_sectors but
+ * may round it down.
+ *
+ * Returns 0 on success, -EFBIG if the size is larger than ~2 TB. Override
+ * the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB)
+ * and instead allow up to 255 heads.
+ */
+static int calculate_geometry(int64_t total_sectors, uint16_t* cyls,
+ uint8_t* heads, uint8_t* secs_per_cyl)
+{
+ uint32_t cyls_times_heads;
+
+ total_sectors = MIN(total_sectors, VHD_MAX_GEOMETRY);
+
+ if (total_sectors >= 65535LL * 16 * 63) {
+ *secs_per_cyl = 255;
+ *heads = 16;
+ cyls_times_heads = total_sectors / *secs_per_cyl;
+ } else {
+ *secs_per_cyl = 17;
+ cyls_times_heads = total_sectors / *secs_per_cyl;
+ *heads = (cyls_times_heads + 1023) / 1024;
+
+ if (*heads < 4) {
+ *heads = 4;
+ }
+
+ if (cyls_times_heads >= (*heads * 1024) || *heads > 16) {
+ *secs_per_cyl = 31;
+ *heads = 16;
+ cyls_times_heads = total_sectors / *secs_per_cyl;
+ }
+
+ if (cyls_times_heads >= (*heads * 1024)) {
+ *secs_per_cyl = 63;
+ *heads = 16;
+ cyls_times_heads = total_sectors / *secs_per_cyl;
+ }
+ }
+
+ *cyls = cyls_times_heads / *heads;
+
+ return 0;
+}
+
+static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf,
+ int64_t total_sectors)
+{
+ VHDDynDiskHeader *dyndisk_header =
+ (VHDDynDiskHeader *) buf;
+ size_t block_size, num_bat_entries;
+ int i;
+ int ret;
+ int64_t offset = 0;
+
+ // Write the footer (twice: at the beginning and at the end)
+ block_size = 0x200000;
+ num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512);
+
+ ret = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE);
+ if (ret) {
+ goto fail;
+ }
+
+ offset = 1536 + ((num_bat_entries * 4 + 511) & ~511);
+ ret = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ // Write the initial BAT
+ offset = 3 * 512;
+
+ memset(buf, 0xFF, 512);
+ for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) {
+ ret = bdrv_pwrite_sync(bs, offset, buf, 512);
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += 512;
+ }
+
+ // Prepare the Dynamic Disk Header
+ memset(buf, 0, 1024);
+
+ memcpy(dyndisk_header->magic, "cxsparse", 8);
+
+ /*
+ * Note: The spec is actually wrong here for data_offset, it says
+ * 0xFFFFFFFF, but MS tools expect all 64 bits to be set.
+ */
+ dyndisk_header->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL);
+ dyndisk_header->table_offset = cpu_to_be64(3 * 512);
+ dyndisk_header->version = cpu_to_be32(0x00010000);
+ dyndisk_header->block_size = cpu_to_be32(block_size);
+ dyndisk_header->max_table_entries = cpu_to_be32(num_bat_entries);
+
+ dyndisk_header->checksum = cpu_to_be32(vpc_checksum(buf, 1024));
+
+ // Write the header
+ offset = 512;
+
+ ret = bdrv_pwrite_sync(bs, offset, buf, 1024);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ fail:
+ return ret;
+}
+
+static int create_fixed_disk(BlockDriverState *bs, uint8_t *buf,
+ int64_t total_size)
+{
+ int ret;
+
+ /* Add footer to total size */
+ total_size += HEADER_SIZE;
+
+ ret = bdrv_truncate(bs, total_size);
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = bdrv_pwrite_sync(bs, total_size - HEADER_SIZE, buf, HEADER_SIZE);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return ret;
+}
+
+static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
+{
+ uint8_t buf[1024];
+ VHDFooter *footer = (VHDFooter *) buf;
+ char *disk_type_param;
+ int i;
+ uint16_t cyls = 0;
+ uint8_t heads = 0;
+ uint8_t secs_per_cyl = 0;
+ int64_t total_sectors;
+ int64_t total_size;
+ int disk_type;
+ int ret = -EIO;
+ Error *local_err = NULL;
+ BlockDriverState *bs = NULL;
+
+ /* Read out options */
+ total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+ BDRV_SECTOR_SIZE);
+ disk_type_param = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);
+ if (disk_type_param) {
+ if (!strcmp(disk_type_param, "dynamic")) {
+ disk_type = VHD_DYNAMIC;
+ } else if (!strcmp(disk_type_param, "fixed")) {
+ disk_type = VHD_FIXED;
+ } else {
+ ret = -EINVAL;
+ goto out;
+ }
+ } else {
+ disk_type = VHD_DYNAMIC;
+ }
+
+ ret = bdrv_create_file(filename, opts, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ goto out;
+ }
+ ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
+ NULL, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ goto out;
+ }
+
+ /*
+ * Calculate matching total_size and geometry. Increase the number of
+ * sectors requested until we get enough (or fail). This ensures that
+ * qemu-img convert doesn't truncate images, but rather rounds up.
+ *
+ * If the image size can't be represented by a spec conform CHS geometry,
+ * we set the geometry to 65535 x 16 x 255 (CxHxS) sectors and use
+ * the image size from the VHD footer to calculate total_sectors.
+ */
+ total_sectors = MIN(VHD_MAX_GEOMETRY, total_size / BDRV_SECTOR_SIZE);
+ for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
+ calculate_geometry(total_sectors + i, &cyls, &heads, &secs_per_cyl);
+ }
+
+ if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) {
+ total_sectors = total_size / BDRV_SECTOR_SIZE;
+ /* Allow a maximum disk size of approximately 2 TB */
+ if (total_sectors > VHD_MAX_SECTORS) {
+ ret = -EFBIG;
+ goto out;
+ }
+ } else {
+ total_sectors = (int64_t)cyls * heads * secs_per_cyl;
+ total_size = total_sectors * BDRV_SECTOR_SIZE;
+ }
+
+ /* Prepare the Hard Disk Footer */
+ memset(buf, 0, 1024);
+
+ memcpy(footer->creator, "conectix", 8);
+ /* TODO Check if "qemu" creator_app is ok for VPC */
+ memcpy(footer->creator_app, "qemu", 4);
+ memcpy(footer->creator_os, "Wi2k", 4);
+
+ footer->features = cpu_to_be32(0x02);
+ footer->version = cpu_to_be32(0x00010000);
+ if (disk_type == VHD_DYNAMIC) {
+ footer->data_offset = cpu_to_be64(HEADER_SIZE);
+ } else {
+ footer->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL);
+ }
+ footer->timestamp = cpu_to_be32(time(NULL) - VHD_TIMESTAMP_BASE);
+
+ /* Version of Virtual PC 2007 */
+ footer->major = cpu_to_be16(0x0005);
+ footer->minor = cpu_to_be16(0x0003);
+ footer->orig_size = cpu_to_be64(total_size);
+ footer->current_size = cpu_to_be64(total_size);
+ footer->cyls = cpu_to_be16(cyls);
+ footer->heads = heads;
+ footer->secs_per_cyl = secs_per_cyl;
+
+ footer->type = cpu_to_be32(disk_type);
+
+#if defined(CONFIG_UUID)
+ uuid_generate(footer->uuid);
+#endif
+
+ footer->checksum = cpu_to_be32(vpc_checksum(buf, HEADER_SIZE));
+
+ if (disk_type == VHD_DYNAMIC) {
+ ret = create_dynamic_disk(bs, buf, total_sectors);
+ } else {
+ ret = create_fixed_disk(bs, buf, total_size);
+ }
+
+out:
+ bdrv_unref(bs);
+ g_free(disk_type_param);
+ return ret;
+}
+
+static int vpc_has_zero_init(BlockDriverState *bs)
+{
+ BDRVVPCState *s = bs->opaque;
+ VHDFooter *footer = (VHDFooter *) s->footer_buf;
+
+ if (be32_to_cpu(footer->type) == VHD_FIXED) {
+ return bdrv_has_zero_init(bs->file);
+ } else {
+ return 1;
+ }
+}
+
+static void vpc_close(BlockDriverState *bs)
+{
+ BDRVVPCState *s = bs->opaque;
+ qemu_vfree(s->pagetable);
+#ifdef CACHE
+ g_free(s->pageentry_u8);
+#endif
+
+ migrate_del_blocker(s->migration_blocker);
+ error_free(s->migration_blocker);
+}
+
+static QemuOptsList vpc_create_opts = {
+ .name = "vpc-create-opts",
+ .head = QTAILQ_HEAD_INITIALIZER(vpc_create_opts.head),
+ .desc = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_OPT_SUBFMT,
+ .type = QEMU_OPT_STRING,
+ .help =
+ "Type of virtual hard disk format. Supported formats are "
+ "{dynamic (default) | fixed} "
+ },
+ { /* end of list */ }
+ }
+};
+
+static BlockDriver bdrv_vpc = {
+ .format_name = "vpc",
+ .instance_size = sizeof(BDRVVPCState),
+
+ .bdrv_probe = vpc_probe,
+ .bdrv_open = vpc_open,
+ .bdrv_close = vpc_close,
+ .bdrv_reopen_prepare = vpc_reopen_prepare,
+ .bdrv_create = vpc_create,
+
+ .bdrv_read = vpc_co_read,
+ .bdrv_write = vpc_co_write,
+ .bdrv_co_get_block_status = vpc_co_get_block_status,
+
+ .bdrv_get_info = vpc_get_info,
+
+ .create_opts = &vpc_create_opts,
+ .bdrv_has_zero_init = vpc_has_zero_init,
+};
+
+static void bdrv_vpc_init(void)
+{
+ bdrv_register(&bdrv_vpc);
+}
+
+block_init(bdrv_vpc_init);