uint64_t ptimer_get_count(ptimer_state *s)
{
uint64_t counter;
if (s->enabled) {
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
int64_t next = s->next_event;
bool expired = (now - next >= 0);
bool oneshot = (s->enabled == 2);
/* Figure out the current counter value. */
if (expired) {
/* Prevent timer underflowing if it should already have
triggered. */
counter = 0;
} else {
uint64_t rem;
uint64_t div;
int clz1, clz2;
int shift;
uint32_t period_frac = s->period_frac;
uint64_t period = s->period;
if (!oneshot && (s->delta * period < 10000) && !use_icount) {
period = 10000 / s->delta;
period_frac = 0;
}
/* We need to divide time by period, where time is stored in
rem (64-bit integer) and period is stored in period/period_frac
(64.32 fixed point).
Doing full precision division is hard, so scale values and
do a 64-bit division. The result should be rounded down,
so that the rounding error never causes the timer to go
backwards.
*/
rem = next - now;
div = period;
clz1 = clz64(rem);
clz2 = clz64(div);
shift = clz1 < clz2 ? clz1 : clz2;
rem <<= shift;
div <<= shift;
if (shift >= 32) {
div |= ((uint64_t)period_frac << (shift - 32));
} else {
if (shift != 0)
div |= (period_frac >> (32 - shift));
/* Look at remaining bits of period_frac and round div up if
necessary. */
if ((uint32_t)(period_frac << shift))
div += 1;
}
counter = rem / div;
}
} else {
unsigned
StdpProcess::closestPostFire(uint64_t arrivals) const
{
uint64_t validArrivals = arrivals & m_postPreBits;
int dt = clz64(validArrivals << uint64_t(64 - m_postPreWindow));
return validArrivals ? (unsigned) dt : STDP_NO_APPLICATION;
}
/* calculate condition code for insert character under mask insn */
static uint32_t cc_calc_icm(uint64_t mask, uint64_t val)
{
if ((val & mask) == 0) {
return 0;
} else {
int top = clz64(mask);
if ((int64_t)(val << top) < 0) {
return 1;
} else {
return 2;
}
}
}
static uint32_t cc_calc_tm_64(uint64_t val, uint64_t mask)
{
uint64_t r = val & mask;
if (r == 0) {
return 0;
} else if (r == mask) {
return 3;
} else {
int top = clz64(mask);
if ((int64_t)(val << top) < 0) {
return 2;
} else {
return 1;
}
}
}
/* count leading zeros, for find leftmost one */
uint64_t HELPER(clz)(uint64_t v)
{
return clz64(v);
}
uint64_t HELPER(clz_i64)(uint64_t arg, uint64_t zero_val)
{
return arg ? clz64(arg) : zero_val;
}
/* Metadata initial parser
*
* This loads all the metadata entry fields. This may cause additional
* fields to be processed (e.g. parent locator, etc..).
*
* There are 5 Metadata items that are always required:
* - File Parameters (block size, has a parent)
* - Virtual Disk Size (size, in bytes, of the virtual drive)
* - Page 83 Data (scsi page 83 guid)
* - Logical Sector Size (logical sector size in bytes, either 512 or
* 4096. We only support 512 currently)
* - Physical Sector Size (512 or 4096)
*
* Also, if the File Parameters indicate this is a differencing file,
* we must also look for the Parent Locator metadata item.
*/
static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s)
{
int ret = 0;
uint8_t *buffer;
int offset = 0;
uint32_t i = 0;
VHDXMetadataTableEntry md_entry;
buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE);
ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer,
VHDX_METADATA_TABLE_MAX_SIZE);
if (ret < 0) {
goto exit;
}
memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr));
offset += sizeof(s->metadata_hdr);
le64_to_cpus(&s->metadata_hdr.signature);
le16_to_cpus(&s->metadata_hdr.reserved);
le16_to_cpus(&s->metadata_hdr.entry_count);
if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.present = 0;
if ((s->metadata_hdr.entry_count * sizeof(md_entry)) >
(VHDX_METADATA_TABLE_MAX_SIZE - offset)) {
ret = -EINVAL;
goto exit;
}
for (i = 0; i < s->metadata_hdr.entry_count; i++) {
memcpy(&md_entry, buffer + offset, sizeof(md_entry));
offset += sizeof(md_entry);
leguid_to_cpus(&md_entry.item_id);
le32_to_cpus(&md_entry.offset);
le32_to_cpus(&md_entry.length);
le32_to_cpus(&md_entry.data_bits);
le32_to_cpus(&md_entry.reserved2);
if (guid_eq(md_entry.item_id, file_param_guid)) {
if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.file_parameters_entry = md_entry;
s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT;
continue;
}
if (guid_eq(md_entry.item_id, virtual_size_guid)) {
if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.virtual_disk_size_entry = md_entry;
s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT;
continue;
}
if (guid_eq(md_entry.item_id, page83_guid)) {
if (s->metadata_entries.present & META_PAGE_83_PRESENT) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.page83_data_entry = md_entry;
s->metadata_entries.present |= META_PAGE_83_PRESENT;
continue;
}
if (guid_eq(md_entry.item_id, logical_sector_guid)) {
if (s->metadata_entries.present &
META_LOGICAL_SECTOR_SIZE_PRESENT) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.logical_sector_size_entry = md_entry;
s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT;
continue;
}
if (guid_eq(md_entry.item_id, phys_sector_guid)) {
if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.phys_sector_size_entry = md_entry;
s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT;
continue;
}
if (guid_eq(md_entry.item_id, parent_locator_guid)) {
if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
ret = -EINVAL;
goto exit;
}
s->metadata_entries.parent_locator_entry = md_entry;
s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT;
continue;
}
if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) {
/* cannot read vhdx file - required region table entry that
* we do not understand. per spec, we must fail to open */
ret = -ENOTSUP;
goto exit;
}
}
if (s->metadata_entries.present != META_ALL_PRESENT) {
ret = -ENOTSUP;
goto exit;
}
ret = bdrv_pread(bs->file,
s->metadata_entries.file_parameters_entry.offset
+ s->metadata_rt.file_offset,
&s->params,
sizeof(s->params));
if (ret < 0) {
goto exit;
}
le32_to_cpus(&s->params.block_size);
le32_to_cpus(&s->params.data_bits);
/* We now have the file parameters, so we can tell if this is a
* differencing file (i.e.. has_parent), is dynamic or fixed
* sized (leave_blocks_allocated), and the block size */
/* The parent locator required iff the file parameters has_parent set */
if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
/* TODO: parse parent locator fields */
ret = -ENOTSUP; /* temp, until differencing files are supported */
goto exit;
} else {
/* if has_parent is set, but there is not parent locator present,
* then that is an invalid combination */
ret = -EINVAL;
goto exit;
}
}
/* determine virtual disk size, logical sector size,
* and phys sector size */
ret = bdrv_pread(bs->file,
s->metadata_entries.virtual_disk_size_entry.offset
+ s->metadata_rt.file_offset,
&s->virtual_disk_size,
sizeof(uint64_t));
if (ret < 0) {
goto exit;
}
ret = bdrv_pread(bs->file,
s->metadata_entries.logical_sector_size_entry.offset
+ s->metadata_rt.file_offset,
&s->logical_sector_size,
sizeof(uint32_t));
if (ret < 0) {
goto exit;
}
ret = bdrv_pread(bs->file,
s->metadata_entries.phys_sector_size_entry.offset
+ s->metadata_rt.file_offset,
&s->physical_sector_size,
sizeof(uint32_t));
if (ret < 0) {
goto exit;
}
le64_to_cpus(&s->virtual_disk_size);
le32_to_cpus(&s->logical_sector_size);
le32_to_cpus(&s->physical_sector_size);
if (s->logical_sector_size == 0 || s->params.block_size == 0) {
ret = -EINVAL;
goto exit;
}
/* both block_size and sector_size are guaranteed powers of 2 */
s->sectors_per_block = s->params.block_size / s->logical_sector_size;
s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
(uint64_t)s->logical_sector_size /
(uint64_t)s->params.block_size;
/* These values are ones we will want to use for division / multiplication
* later on, and they are all guaranteed (per the spec) to be powers of 2,
* so we can take advantage of that for shift operations during
* reads/writes */
if (s->logical_sector_size & (s->logical_sector_size - 1)) {
ret = -EINVAL;
goto exit;
}
if (s->sectors_per_block & (s->sectors_per_block - 1)) {
ret = -EINVAL;
goto exit;
}
if (s->chunk_ratio & (s->chunk_ratio - 1)) {
ret = -EINVAL;
goto exit;
}
s->block_size = s->params.block_size;
if (s->block_size & (s->block_size - 1)) {
ret = -EINVAL;
goto exit;
}
s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size);
s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block);
s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio);
s->block_size_bits = 31 - clz32(s->block_size);
ret = 0;
exit:
qemu_vfree(buffer);
return ret;
}
/* round down to the nearest power of 2*/
int64_t pow2floor(int64_t value)
{
if (!is_power_of_2(value)) {
value = 0x8000000000000000ULL >> clz64(value);
}
uint64_t HELPER(clz64)(uint64_t x)
{
return clz64(x);
}
