diff options
Diffstat (limited to 'block/vpc.c')
| -rw-r--r-- | block/vpc.c | 165 |
1 files changed, 138 insertions, 27 deletions
diff --git a/block/vpc.c b/block/vpc.c index f504536..0d1524d 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -25,6 +25,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "block/block_int.h" +#include "sysemu/block-backend.h" #include "qemu/module.h" #include "migration/migration.h" #if defined(CONFIG_UUID) @@ -46,8 +47,14 @@ enum vhd_type { // Seconds since Jan 1, 2000 0:00:00 (UTC) #define VHD_TIMESTAMP_BASE 946684800 +#define VHD_CHS_MAX_C 65535LL +#define VHD_CHS_MAX_H 16 +#define VHD_CHS_MAX_S 255 + #define VHD_MAX_SECTORS (65535LL * 255 * 255) -#define VHD_MAX_GEOMETRY (65535LL * 16 * 255) +#define VHD_MAX_GEOMETRY (VHD_CHS_MAX_C * VHD_CHS_MAX_H * VHD_CHS_MAX_S) + +#define VPC_OPT_FORCE_SIZE "force_size" // always big-endian typedef struct vhd_footer { @@ -128,6 +135,8 @@ typedef struct BDRVVPCState { uint32_t block_size; uint32_t bitmap_size; + bool force_use_chs; + bool force_use_sz; #ifdef CACHE uint8_t *pageentry_u8; @@ -140,6 +149,22 @@ typedef struct BDRVVPCState { Error *migration_blocker; } BDRVVPCState; +#define VPC_OPT_SIZE_CALC "force_size_calc" +static QemuOptsList vpc_runtime_opts = { + .name = "vpc-runtime-opts", + .head = QTAILQ_HEAD_INITIALIZER(vpc_runtime_opts.head), + .desc = { + { + .name = VPC_OPT_SIZE_CALC, + .type = QEMU_OPT_STRING, + .help = "Force disk size calculation to use either CHS geometry, " + "or use the disk current_size specified in the VHD footer. " + "{chs, current_size}" + }, + { /* end of list */ } + } +}; + static uint32_t vpc_checksum(uint8_t* buf, size_t size) { uint32_t res = 0; @@ -159,6 +184,25 @@ static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename) return 0; } +static void vpc_parse_options(BlockDriverState *bs, QemuOpts *opts, + Error **errp) +{ + BDRVVPCState *s = bs->opaque; + const char *size_calc; + + size_calc = qemu_opt_get(opts, VPC_OPT_SIZE_CALC); + + if (!size_calc) { + /* no override, use autodetect only */ + } else if (!strcmp(size_calc, "current_size")) { + s->force_use_sz = true; + } else if (!strcmp(size_calc, "chs")) { + s->force_use_chs = true; + } else { + error_setg(errp, "Invalid size calculation mode: '%s'", size_calc); + } +} + static int vpc_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { @@ -166,6 +210,9 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, int i; VHDFooter *footer; VHDDynDiskHeader *dyndisk_header; + QemuOpts *opts = NULL; + Error *local_err = NULL; + bool use_chs; uint8_t buf[HEADER_SIZE]; uint32_t checksum; uint64_t computed_size; @@ -173,6 +220,21 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, int disk_type = VHD_DYNAMIC; int ret; + opts = qemu_opts_create(&vpc_runtime_opts, NULL, 0, &error_abort); + qemu_opts_absorb_qdict(opts, options, &local_err); + if (local_err) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto fail; + } + + vpc_parse_options(bs, opts, &local_err); + if (local_err) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto fail; + } + ret = bdrv_pread(bs->file->bs, 0, s->footer_buf, HEADER_SIZE); if (ret < 0) { goto fail; @@ -218,12 +280,36 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, 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) { + /* Microsoft Virtual PC and Microsoft Hyper-V produce and read + * VHD image sizes differently. VPC will rely on CHS geometry, + * while Hyper-V and disk2vhd use the size specified in the footer. + * + * We use a couple of approaches to try and determine the correct method: + * look at the Creator App field, and look for images that have CHS + * geometry that is the maximum value. + * + * If the CHS geometry is the maximum CHS geometry, then we assume that + * the size is the footer->current_size to avoid truncation. Otherwise, + * we follow the table based on footer->creator_app: + * + * Known creator apps: + * 'vpc ' : CHS Virtual PC (uses disk geometry) + * 'qemu' : CHS QEMU (uses disk geometry) + * 'qem2' : current_size QEMU (uses current_size) + * 'win ' : current_size Hyper-V + * 'd2v ' : current_size Disk2vhd + * + * The user can override the table values via drive options, however + * even with an override we will still use current_size for images + * that have CHS geometry of the maximum size. + */ + use_chs = (!!strncmp(footer->creator_app, "win ", 4) && + !!strncmp(footer->creator_app, "qem2", 4) && + !!strncmp(footer->creator_app, "d2v ", 4)) || s->force_use_chs; + + if (!use_chs || bs->total_sectors == VHD_MAX_GEOMETRY || s->force_use_sz) { bs->total_sectors = be64_to_cpu(footer->current_size) / - BDRV_SECTOR_SIZE; + BDRV_SECTOR_SIZE; } /* Allow a maximum disk size of approximately 2 TB */ @@ -673,7 +759,7 @@ static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, return 0; } -static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf, +static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf, int64_t total_sectors) { VHDDynDiskHeader *dyndisk_header = @@ -687,13 +773,13 @@ static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf, block_size = 0x200000; num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512); - ret = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE); + ret = blk_pwrite(blk, 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); + ret = blk_pwrite(blk, offset, buf, HEADER_SIZE); if (ret < 0) { goto fail; } @@ -703,7 +789,7 @@ static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf, memset(buf, 0xFF, 512); for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) { - ret = bdrv_pwrite_sync(bs, offset, buf, 512); + ret = blk_pwrite(blk, offset, buf, 512); if (ret < 0) { goto fail; } @@ -730,7 +816,7 @@ static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf, // Write the header offset = 512; - ret = bdrv_pwrite_sync(bs, offset, buf, 1024); + ret = blk_pwrite(blk, offset, buf, 1024); if (ret < 0) { goto fail; } @@ -739,7 +825,7 @@ static int create_dynamic_disk(BlockDriverState *bs, uint8_t *buf, return ret; } -static int create_fixed_disk(BlockDriverState *bs, uint8_t *buf, +static int create_fixed_disk(BlockBackend *blk, uint8_t *buf, int64_t total_size) { int ret; @@ -747,12 +833,12 @@ static int create_fixed_disk(BlockDriverState *bs, uint8_t *buf, /* Add footer to total size */ total_size += HEADER_SIZE; - ret = bdrv_truncate(bs, total_size); + ret = blk_truncate(blk, total_size); if (ret < 0) { return ret; } - ret = bdrv_pwrite_sync(bs, total_size - HEADER_SIZE, buf, HEADER_SIZE); + ret = blk_pwrite(blk, total_size - HEADER_SIZE, buf, HEADER_SIZE); if (ret < 0) { return ret; } @@ -773,8 +859,9 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp) int64_t total_size; int disk_type; int ret = -EIO; + bool force_size; Error *local_err = NULL; - BlockDriverState *bs = NULL; + BlockBackend *blk = NULL; /* Read out options */ total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), @@ -793,30 +880,44 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp) disk_type = VHD_DYNAMIC; } + force_size = qemu_opt_get_bool_del(opts, VPC_OPT_FORCE_SIZE, false); + 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, - &local_err); - if (ret < 0) { + + blk = blk_new_open("image", filename, NULL, NULL, + BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL, + &local_err); + if (blk == NULL) { error_propagate(errp, local_err); + ret = -EIO; goto out; } + blk_set_allow_write_beyond_eof(blk, true); + /* * 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, + * If the image size can't be represented by a spec conformant 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 (force_size) { + /* This will force the use of total_size for sector count, below */ + cyls = VHD_CHS_MAX_C; + heads = VHD_CHS_MAX_H; + secs_per_cyl = VHD_CHS_MAX_S; + } else { + 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) { @@ -835,8 +936,11 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp) 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); + if (force_size) { + memcpy(footer->creator_app, "qem2", 4); + } else { + memcpy(footer->creator_app, "qemu", 4); + } memcpy(footer->creator_os, "Wi2k", 4); footer->features = cpu_to_be32(0x02); @@ -866,13 +970,13 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp) footer->checksum = cpu_to_be32(vpc_checksum(buf, HEADER_SIZE)); if (disk_type == VHD_DYNAMIC) { - ret = create_dynamic_disk(bs, buf, total_sectors); + ret = create_dynamic_disk(blk, buf, total_sectors); } else { - ret = create_fixed_disk(bs, buf, total_size); + ret = create_fixed_disk(blk, buf, total_size); } out: - bdrv_unref(bs); + blk_unref(blk); g_free(disk_type_param); return ret; } @@ -917,6 +1021,13 @@ static QemuOptsList vpc_create_opts = { "Type of virtual hard disk format. Supported formats are " "{dynamic (default) | fixed} " }, + { + .name = VPC_OPT_FORCE_SIZE, + .type = QEMU_OPT_BOOL, + .help = "Force disk size calculation to use the actual size " + "specified, rather than using the nearest CHS-based " + "calculation" + }, { /* end of list */ } } }; |