diff options
Diffstat (limited to 'block/vpc.c')
| -rw-r--r-- | block/vpc.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/block/vpc.c b/block/vpc.c index 82229ef5a0..b4ff5646a2 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -34,6 +34,8 @@ #define HEADER_SIZE 512 +#define VHD_SECTOR_SIZE 512 + //#define CACHE enum vhd_type { @@ -204,11 +206,13 @@ static int vpc_open(BlockDriverState *bs, int flags) /* Write 'checksum' back to footer, or else will leave it with zero. */ footer->checksum = be32_to_cpu(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; + /* The visible size of a image in Virtual PC depends on the guest: + * QEMU and other emulators report the real size (here in sectors). + * All modern operating systems use this real size. + * Very old operating systems use CHS values to calculate the total size. + * This calculated size is usually smaller than the real size. + */ + bs->total_sectors = be64_to_cpu(footer->size) / VHD_SECTOR_SIZE; /* Allow a maximum disk size of approximately 2 TB */ if (bs->total_sectors >= 65535LL * 255 * 255) { |