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block: VHDX endian fixes

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This patch contains several changes for endian conversion fixes for
VHDX, particularly for big-endian machines (multibyte values in VHDX are
all on disk in LE format).

Tests were done with existing qemu-iotests on an IBM POWER7 (8406-71Y).
This includes sample images created by Hyper-V, both with dirty logs and
without.

In addition, VHDX image files created (and written to) on a BE machine
were tested on a LE machine, and vice-versa.

Reported-by: Markus Armburster <armbru@redhat.com>
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Jeff Cody 2014-08-06 15:54:58 -04:00 • committed by Kevin Wolf
parent 349592e0b9
commit 4f75b52a07
4 changed files with 88 additions and 56 deletions
Download patch file Download diff file Expand all files Collapse all files

43
block/vhdx-log.c
View file

@ -84,6 +84,7 @@ static int vhdx_log_peek_hdr(BlockDriverState *bs, VHDXLogEntries *log,
if (ret < 0) {
goto exit;
}
vhdx_log_entry_hdr_le_import(hdr);
exit:
return ret;
@ -211,7 +212,7 @@ static bool vhdx_log_hdr_is_valid(VHDXLogEntries *log, VHDXLogEntryHeader *hdr,
{
int valid = false;
if (memcmp(&hdr->signature, "loge", 4)) {
if (hdr->signature != VHDX_LOG_SIGNATURE) {
goto exit;
}
@ -275,12 +276,12 @@ static bool vhdx_log_desc_is_valid(VHDXLogDescriptor *desc,
goto exit;
}
if (!memcmp(&desc->signature, "zero", 4)) {
if (desc->signature == VHDX_LOG_ZERO_SIGNATURE) {
if (desc->zero_length % VHDX_LOG_SECTOR_SIZE == 0) {
/* valid */
ret = true;
}
} else if (!memcmp(&desc->signature, "desc", 4)) {
} else if (desc->signature == VHDX_LOG_DESC_SIGNATURE) {
/* valid */
ret = true;
}
@ -327,13 +328,15 @@ static int vhdx_compute_desc_sectors(uint32_t desc_cnt)
* passed into this function. Each descriptor will also be validated,
* and error returned if any are invalid. */
static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s,
VHDXLogEntries *log, VHDXLogDescEntries **buffer)
VHDXLogEntries *log, VHDXLogDescEntries **buffer,
bool convert_endian)
{
int ret = 0;
uint32_t desc_sectors;
uint32_t sectors_read;
VHDXLogEntryHeader hdr;
VHDXLogDescEntries *desc_entries = NULL;
VHDXLogDescriptor desc;
int i;
assert(*buffer == NULL);
@ -342,7 +345,7 @@ static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s,
if (ret < 0) {
goto exit;
}
vhdx_log_entry_hdr_le_import(&hdr);
if (vhdx_log_hdr_is_valid(log, &hdr, s) == false) {
ret = -EINVAL;
goto exit;
@ -363,12 +366,19 @@ static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s,
/* put in proper endianness, and validate each desc */
for (i = 0; i < hdr.descriptor_count; i++) {
vhdx_log_desc_le_import(&desc_entries->desc[i]);
if (vhdx_log_desc_is_valid(&desc_entries->desc[i], &hdr) == false) {
desc = desc_entries->desc[i];
vhdx_log_desc_le_import(&desc);
if (convert_endian) {
desc_entries->desc[i] = desc;
}
if (vhdx_log_desc_is_valid(&desc, &hdr) == false) {
ret = -EINVAL;
goto free_and_exit;
}
}
if (convert_endian) {
desc_entries->hdr = hdr;
}
*buffer = desc_entries;
goto exit;
@ -403,7 +413,7 @@ static int vhdx_log_flush_desc(BlockDriverState *bs, VHDXLogDescriptor *desc,
buffer = qemu_blockalign(bs, VHDX_LOG_SECTOR_SIZE);
if (!memcmp(&desc->signature, "desc", 4)) {
if (desc->signature == VHDX_LOG_DESC_SIGNATURE) {
/* data sector */
if (data == NULL) {
ret = -EFAULT;
@ -431,7 +441,7 @@ static int vhdx_log_flush_desc(BlockDriverState *bs, VHDXLogDescriptor *desc,
memcpy(buffer+offset, &desc->trailing_bytes, 4);
} else if (!memcmp(&desc->signature, "zero", 4)) {
} else if (desc->signature == VHDX_LOG_ZERO_SIGNATURE) {
/* write 'count' sectors of sector */
memset(buffer, 0, VHDX_LOG_SECTOR_SIZE);
count = desc->zero_length / VHDX_LOG_SECTOR_SIZE;
@ -498,13 +508,13 @@ static int vhdx_log_flush(BlockDriverState *bs, BDRVVHDXState *s,
goto exit;
}
ret = vhdx_log_read_desc(bs, s, &logs->log, &desc_entries);
ret = vhdx_log_read_desc(bs, s, &logs->log, &desc_entries, true);
if (ret < 0) {
goto exit;
}
for (i = 0; i < desc_entries->hdr.descriptor_count; i++) {
if (!memcmp(&desc_entries->desc[i].signature, "desc", 4)) {
if (desc_entries->desc[i].signature == VHDX_LOG_DESC_SIGNATURE) {
/* data sector, so read a sector to flush */
ret = vhdx_log_read_sectors(bs, &logs->log, &sectors_read,
data, 1, false);
@ -515,6 +525,7 @@ static int vhdx_log_flush(BlockDriverState *bs, BDRVVHDXState *s,
ret = -EINVAL;
goto exit;
}
vhdx_log_data_le_import(data);
}
ret = vhdx_log_flush_desc(bs, &desc_entries->desc[i], data);
@ -563,9 +574,6 @@ static int vhdx_validate_log_entry(BlockDriverState *bs, BDRVVHDXState *s,
goto inc_and_exit;
}
vhdx_log_entry_hdr_le_import(&hdr);
if (vhdx_log_hdr_is_valid(log, &hdr, s) == false) {
goto inc_and_exit;
}
@ -578,13 +586,13 @@ static int vhdx_validate_log_entry(BlockDriverState *bs, BDRVVHDXState *s,
desc_sectors = vhdx_compute_desc_sectors(hdr.descriptor_count);
/* Read desc sectors, and calculate log checksum */
/* Read all log sectors, and calculate log checksum */
total_sectors = hdr.entry_length / VHDX_LOG_SECTOR_SIZE;
/* read_desc() will increment the read idx */
ret = vhdx_log_read_desc(bs, s, log, &desc_buffer);
ret = vhdx_log_read_desc(bs, s, log, &desc_buffer, false);
if (ret < 0) {
goto free_and_exit;
}
@ -607,7 +615,7 @@ static int vhdx_validate_log_entry(BlockDriverState *bs, BDRVVHDXState *s,
}
}
crc ^= 0xffffffff;
if (crc != desc_buffer->hdr.checksum) {
if (crc != hdr.checksum) {
goto free_and_exit;
}
@ -967,7 +975,6 @@ static int vhdx_log_write(BlockDriverState *bs, BDRVVHDXState *s,
* last data sector */
vhdx_update_checksum(buffer, total_length,
offsetof(VHDXLogEntryHeader, checksum));
cpu_to_le32s((uint32_t *)(buffer + 4));
/* now write to the log */
ret = vhdx_log_write_sectors(bs, &s->log, &sectors_written, buffer,