diff options
| -rw-r--r-- | block/qcow2.c | 66 | ||||
| -rw-r--r-- | block/qcow2.h | 12 |
2 files changed, 69 insertions, 9 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 9a8b354d0e..41b195d91b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -54,6 +54,7 @@ typedef struct { } QCowExtension; #define QCOW2_EXT_MAGIC_END 0 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA +#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) { @@ -76,7 +77,7 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) * return 0 upon success, non-0 otherwise */ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, - uint64_t end_offset) + uint64_t end_offset, void **p_feature_table) { BDRVQcowState *s = bs->opaque; QCowExtension ext; @@ -134,6 +135,18 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, #endif break; + case QCOW2_EXT_MAGIC_FEATURE_TABLE: + if (p_feature_table != NULL) { + void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); + ret = bdrv_pread(bs->file, offset , feature_table, ext.len); + if (ret < 0) { + return ret; + } + + *p_feature_table = feature_table; + } + break; + default: /* unknown magic - save it in case we need to rewrite the header */ { @@ -182,6 +195,24 @@ static void report_unsupported(BlockDriverState *bs, const char *fmt, ...) bs->device_name, "qcow2", msg); } +static void report_unsupported_feature(BlockDriverState *bs, + Qcow2Feature *table, uint64_t mask) +{ + while (table && table->name[0] != '\0') { + if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { + if (mask & (1 << table->bit)) { + report_unsupported(bs, "%.46s",table->name); + mask &= ~(1 << table->bit); + } + } + table++; + } + + if (mask) { + report_unsupported(bs, "Unknown incompatible feature: %" PRIx64, mask); + } +} + static int qcow2_open(BlockDriverState *bs, int flags) { BDRVQcowState *s = bs->opaque; @@ -245,14 +276,23 @@ static int qcow2_open(BlockDriverState *bs, int flags) } } + if (header.backing_file_offset) { + ext_end = header.backing_file_offset; + } else { + ext_end = 1 << header.cluster_bits; + } + /* Handle feature bits */ s->incompatible_features = header.incompatible_features; s->compatible_features = header.compatible_features; s->autoclear_features = header.autoclear_features; if (s->incompatible_features != 0) { - report_unsupported(bs, "incompatible features mask %" PRIx64, - header.incompatible_features); + void *feature_table = NULL; + qcow2_read_extensions(bs, header.header_length, ext_end, + &feature_table); + report_unsupported_feature(bs, feature_table, + s->incompatible_features); ret = -ENOTSUP; goto fail; } @@ -343,12 +383,7 @@ static int qcow2_open(BlockDriverState *bs, int flags) QLIST_INIT(&s->cluster_allocs); /* read qcow2 extensions */ - if (header.backing_file_offset) { - ext_end = header.backing_file_offset; - } else { - ext_end = s->cluster_size; - } - if (qcow2_read_extensions(bs, header.header_length, ext_end)) { + if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) { ret = -EINVAL; goto fail; } @@ -912,6 +947,19 @@ int qcow2_update_header(BlockDriverState *bs) buflen -= ret; } + /* Feature table */ + Qcow2Feature features[] = { + /* no feature defined yet */ + }; + + ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, + features, sizeof(features), buflen); + if (ret < 0) { + goto fail; + } + buf += ret; + buflen -= ret; + /* Keep unknown header extensions */ QLIST_FOREACH(uext, &s->unknown_header_ext, next) { ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); diff --git a/block/qcow2.h b/block/qcow2.h index df2bdfd0c6..2a982445a1 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -104,6 +104,18 @@ typedef struct Qcow2UnknownHeaderExtension { uint8_t data[]; } Qcow2UnknownHeaderExtension; +enum { + QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, + QCOW2_FEAT_TYPE_COMPATIBLE = 1, + QCOW2_FEAT_TYPE_AUTOCLEAR = 2, +}; + +typedef struct Qcow2Feature { + uint8_t type; + uint8_t bit; + char name[46]; +} QEMU_PACKED Qcow2Feature; + typedef struct BDRVQcowState { int cluster_bits; int cluster_size; |