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ram: Create RAMState 

We create a struct where to put all the ram state

Start with the following fields:

last_seen_block, last_sent_block, last_offset, last_version and
ram_bulk_stage are globals that are really related together.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>

--

Fix typo and warnings
master
Juan Quintela 2017-03-13 19:26:29 +01:00
parent 3644915726
commit 6f37bb8bf3
1 changed files with 83 additions and 57 deletions
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140
migration/ram.c
View File

@ -142,6 +142,23 @@ out:
return ret;
}
/* State of RAM for migration */
struct RAMState {
/* Last block that we have visited searching for dirty pages */
RAMBlock *last_seen_block;
/* Last block from where we have sent data */
RAMBlock *last_sent_block;
/* Last offset we have sent data from */
ram_addr_t last_offset;
/* last ram version we have seen */
uint32_t last_version;
/* We are in the first round */
bool ram_bulk_stage;
};
typedef struct RAMState RAMState;
static RAMState ram_state;
/* accounting for migration statistics */
typedef struct AccountingInfo {
uint64_t dup_pages;
@ -217,16 +234,8 @@ uint64_t xbzrle_mig_pages_overflow(void)
return acct_info.xbzrle_overflows;
}
/* This is the last block that we have visited serching for dirty pages
*/
static RAMBlock *last_seen_block;
/* This is the last block from where we have sent data */
static RAMBlock *last_sent_block;
static ram_addr_t last_offset;
static QemuMutex migration_bitmap_mutex;
static uint64_t migration_dirty_pages;
static uint32_t last_version;
static bool ram_bulk_stage;
/* used by the search for pages to send */
struct PageSearchStatus {
@ -444,6 +453,7 @@ static void mig_throttle_guest_down(void)
/**
* xbzrle_cache_zero_page: insert a zero page in the XBZRLE cache
*
* @rs: current RAM state
* @current_addr: address for the zero page
*
* Update the xbzrle cache to reflect a page that's been sent as all 0.
@ -452,9 +462,9 @@ static void mig_throttle_guest_down(void)
* As a bonus, if the page wasn't in the cache it gets added so that
* when a small write is made into the 0'd page it gets XBZRLE sent.
*/
static void xbzrle_cache_zero_page(ram_addr_t current_addr)
static void xbzrle_cache_zero_page(RAMState *rs, ram_addr_t current_addr)
{
if (ram_bulk_stage || !migrate_use_xbzrle()) {
if (rs->ram_bulk_stage || !migrate_use_xbzrle()) {
return;
}
@ -552,13 +562,14 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
*
* Returns the byte offset within memory region of the start of a dirty page
*
* @rs: current RAM state
* @rb: RAMBlock where to search for dirty pages
* @start: starting address (typically so we can continue from previous page)
* @ram_addr_abs: pointer into which to store the address of the dirty page
* within the global ram_addr space
*/
static inline
ram_addr_t migration_bitmap_find_dirty(RAMBlock *rb,
ram_addr_t migration_bitmap_find_dirty(RAMState *rs, RAMBlock *rb,
ram_addr_t start,
ram_addr_t *ram_addr_abs)
{
@ -571,7 +582,7 @@ ram_addr_t migration_bitmap_find_dirty(RAMBlock *rb,
unsigned long next;
bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
if (ram_bulk_stage && nr > base) {
if (rs->ram_bulk_stage && nr > base) {
next = nr + 1;
} else {
next = find_next_bit(bitmap, size, nr);
@ -761,6 +772,7 @@ static void ram_release_pages(MigrationState *ms, const char *rbname,
* >=0 - Number of pages written - this might legally be 0
* if xbzrle noticed the page was the same.
*
* @rs: current RAM state
* @ms: current migration state
* @f: QEMUFile where to send the data
* @block: block that contains the page we want to send
@ -768,8 +780,9 @@ static void ram_release_pages(MigrationState *ms, const char *rbname,
* @last_stage: if we are at the completion stage
* @bytes_transferred: increase it with the number of transferred bytes
*/
static int ram_save_page(MigrationState *ms, QEMUFile *f, PageSearchStatus *pss,
bool last_stage, uint64_t *bytes_transferred)
static int ram_save_page(RAMState *rs, MigrationState *ms, QEMUFile *f,
PageSearchStatus *pss, bool last_stage,
uint64_t *bytes_transferred)
{
int pages = -1;
uint64_t bytes_xmit;
@ -795,7 +808,7 @@ static int ram_save_page(MigrationState *ms, QEMUFile *f, PageSearchStatus *pss,
current_addr = block->offset + offset;
if (block == last_sent_block) {
if (block == rs->last_sent_block) {
offset |= RAM_SAVE_FLAG_CONTINUE;
}
if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
@ -812,9 +825,9 @@ static int ram_save_page(MigrationState *ms, QEMUFile *f, PageSearchStatus *pss,
/* Must let xbzrle know, otherwise a previous (now 0'd) cached
* page would be stale
*/
xbzrle_cache_zero_page(current_addr);
xbzrle_cache_zero_page(rs, current_addr);
ram_release_pages(ms, block->idstr, pss->offset, pages);
} else if (!ram_bulk_stage &&
} else if (!rs->ram_bulk_stage &&
!migration_in_postcopy(ms) && migrate_use_xbzrle()) {
pages = save_xbzrle_page(f, &p, current_addr, block,
offset, last_stage, bytes_transferred);
@ -946,6 +959,7 @@ static int compress_page_with_multi_thread(QEMUFile *f, RAMBlock *block,
*
* Returns the number of pages written.
*
* @rs: current RAM state
* @ms: current migration state
* @f: QEMUFile where to send the data
* @block: block that contains the page we want to send
@ -953,7 +967,8 @@ static int compress_page_with_multi_thread(QEMUFile *f, RAMBlock *block,
* @last_stage: if we are at the completion stage
* @bytes_transferred: increase it with the number of transferred bytes
*/
static int ram_save_compressed_page(MigrationState *ms, QEMUFile *f,
static int ram_save_compressed_page(RAMState *rs, MigrationState *ms,
QEMUFile *f,
PageSearchStatus *pss, bool last_stage,
uint64_t *bytes_transferred)
{
@ -987,7 +1002,7 @@ static int ram_save_compressed_page(MigrationState *ms, QEMUFile *f,
* out, keeping this order is important, because the 'cont' flag
* is used to avoid resending the block name.
*/
if (block != last_sent_block) {
if (block != rs->last_sent_block) {
flush_compressed_data(f);
pages = save_zero_page(f, block, offset, p, bytes_transferred);
if (pages == -1) {
@ -1029,19 +1044,20 @@ static int ram_save_compressed_page(MigrationState *ms, QEMUFile *f,
*
* Returns if a page is found
*
* @rs: current RAM state
* @f: QEMUFile where to send the data
* @pss: data about the state of the current dirty page scan
* @again: set to false if the search has scanned the whole of RAM
* @ram_addr_abs: pointer into which to store the address of the dirty page
* within the global ram_addr space
*/
static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
static bool find_dirty_block(RAMState *rs, QEMUFile *f, PageSearchStatus *pss,
bool *again, ram_addr_t *ram_addr_abs)
{
pss->offset = migration_bitmap_find_dirty(pss->block, pss->offset,
pss->offset = migration_bitmap_find_dirty(rs, pss->block, pss->offset,
ram_addr_abs);
if (pss->complete_round && pss->block == last_seen_block &&
pss->offset >= last_offset) {
if (pss->complete_round && pss->block == rs->last_seen_block &&
pss->offset >= rs->last_offset) {
/*
* We've been once around the RAM and haven't found anything.
* Give up.
@ -1058,7 +1074,7 @@ static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
pss->block = QLIST_FIRST_RCU(&ram_list.blocks);
/* Flag that we've looped */
pss->complete_round = true;
ram_bulk_stage = false;
rs->ram_bulk_stage = false;
if (migrate_use_xbzrle()) {
/* If xbzrle is on, stop using the data compression at this
* point. In theory, xbzrle can do better than compression.
@ -1125,12 +1141,14 @@ static RAMBlock *unqueue_page(MigrationState *ms, ram_addr_t *offset,
*
* Returns if a queued page is found
*
* @rs: current RAM state
* @ms: current migration state
* @pss: data about the state of the current dirty page scan
* @ram_addr_abs: pointer into which to store the address of the dirty page
* within the global ram_addr space
*/
static bool get_queued_page(MigrationState *ms, PageSearchStatus *pss,
static bool get_queued_page(RAMState *rs, MigrationState *ms,
PageSearchStatus *pss,
ram_addr_t *ram_addr_abs)
{
RAMBlock *block;
@ -1171,7 +1189,7 @@ static bool get_queued_page(MigrationState *ms, PageSearchStatus *pss,
* in (migration_bitmap_find_and_reset_dirty) that every page is
* dirty, that's no longer true.
*/
ram_bulk_stage = false;
rs->ram_bulk_stage = false;
/*
* We want the background search to continue from the queued page
@ -1283,6 +1301,7 @@ err:
*
* Returns the number of pages written
*
* @rs: current RAM state
* @ms: current migration state
* @f: QEMUFile where to send the data
* @pss: data about the page we want to send
@ -1290,7 +1309,7 @@ err:
* @bytes_transferred: increase it with the number of transferred bytes
* @dirty_ram_abs: address of the start of the dirty page in ram_addr_t space
*/
static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
static int ram_save_target_page(RAMState *rs, MigrationState *ms, QEMUFile *f,
PageSearchStatus *pss,
bool last_stage,
uint64_t *bytes_transferred,
@ -1302,11 +1321,11 @@ static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
if (migration_bitmap_clear_dirty(dirty_ram_abs)) {
unsigned long *unsentmap;
if (compression_switch && migrate_use_compression()) {
res = ram_save_compressed_page(ms, f, pss,
res = ram_save_compressed_page(rs, ms, f, pss,
last_stage,
bytes_transferred);
} else {
res = ram_save_page(ms, f, pss, last_stage,
res = ram_save_page(rs, ms, f, pss, last_stage,
bytes_transferred);
}
@ -1322,7 +1341,7 @@ static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
* to the stream.
*/
if (res > 0) {
last_sent_block = pss->block;
rs->last_sent_block = pss->block;
}
}
@ -1340,6 +1359,7 @@ static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
*
* Returns the number of pages written or negative on error
*
* @rs: current RAM state
* @ms: current migration state
* @f: QEMUFile where to send the data
* @pss: data about the page we want to send
@ -1347,7 +1367,7 @@ static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
* @bytes_transferred: increase it with the number of transferred bytes
* @dirty_ram_abs: Address of the start of the dirty page in ram_addr_t space
*/
static int ram_save_host_page(MigrationState *ms, QEMUFile *f,
static int ram_save_host_page(RAMState *rs, MigrationState *ms, QEMUFile *f,
PageSearchStatus *pss,
bool last_stage,
uint64_t *bytes_transferred,
@ -1357,7 +1377,7 @@ static int ram_save_host_page(MigrationState *ms, QEMUFile *f,
size_t pagesize = qemu_ram_pagesize(pss->block);
do {
tmppages = ram_save_target_page(ms, f, pss, last_stage,
tmppages = ram_save_target_page(rs, ms, f, pss, last_stage,
bytes_transferred, dirty_ram_abs);
if (tmppages < 0) {
return tmppages;
@ -1380,6 +1400,7 @@ static int ram_save_host_page(MigrationState *ms, QEMUFile *f,
*
* Returns the number of pages written where zero means no dirty pages
*
* @rs: current RAM state
* @f: QEMUFile where to send the data
* @last_stage: if we are at the completion stage
* @bytes_transferred: increase it with the number of transferred bytes
@ -1388,7 +1409,7 @@ static int ram_save_host_page(MigrationState *ms, QEMUFile *f,
* pages in a host page that are dirty.
*/
static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
static int ram_find_and_save_block(RAMState *rs, QEMUFile *f, bool last_stage,
uint64_t *bytes_transferred)
{
PageSearchStatus pss;
@ -1403,8 +1424,8 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
return pages;
}
pss.block = last_seen_block;
pss.offset = last_offset;
pss.block = rs->last_seen_block;
pss.offset = rs->last_offset;
pss.complete_round = false;
if (!pss.block) {
@ -1413,22 +1434,22 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
do {
again = true;
found = get_queued_page(ms, &pss, &dirty_ram_abs);
found = get_queued_page(rs, ms, &pss, &dirty_ram_abs);
if (!found) {
/* priority queue empty, so just search for something dirty */
found = find_dirty_block(f, &pss, &again, &dirty_ram_abs);
found = find_dirty_block(rs, f, &pss, &again, &dirty_ram_abs);
}
if (found) {
pages = ram_save_host_page(ms, f, &pss,
pages = ram_save_host_page(rs, ms, f, &pss,
last_stage, bytes_transferred,
dirty_ram_abs);
}
} while (!pages && again);
last_seen_block = pss.block;
last_offset = pss.offset;
rs->last_seen_block = pss.block;
rs->last_offset = pss.offset;
return pages;
}
@ -1510,13 +1531,13 @@ static void ram_migration_cleanup(void *opaque)
XBZRLE_cache_unlock();
}
static void reset_ram_globals(void)
static void ram_state_reset(RAMState *rs)
{
last_seen_block = NULL;
last_sent_block = NULL;
last_offset = 0;
last_version = ram_list.version;
ram_bulk_stage = true;
rs->last_seen_block = NULL;
rs->last_sent_block = NULL;
rs->last_offset = 0;
rs->last_version = ram_list.version;
rs->ram_bulk_stage = true;
}
#define MAX_WAIT 50 /* ms, half buffered_file limit */
@ -1848,12 +1869,13 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
*/
static int postcopy_chunk_hostpages(MigrationState *ms)
{
RAMState *rs = &ram_state;
struct RAMBlock *block;
/* Easiest way to make sure we don't resume in the middle of a host-page */
last_seen_block = NULL;
last_sent_block = NULL;
last_offset = 0;
rs->last_seen_block = NULL;
rs->last_sent_block = NULL;
rs->last_offset = 0;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
unsigned long first = block->offset >> TARGET_PAGE_BITS;
@ -1972,7 +1994,7 @@ err:
return ret;
}
static int ram_save_init_globals(void)
static int ram_save_init_globals(RAMState *rs)
{
int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
@ -2018,7 +2040,7 @@ static int ram_save_init_globals(void)
qemu_mutex_lock_ramlist();
rcu_read_lock();
bytes_transferred = 0;
reset_ram_globals();
ram_state_reset(rs);
migration_bitmap_rcu = g_new0(struct BitmapRcu, 1);
/* Skip setting bitmap if there is no RAM */
@ -2065,11 +2087,12 @@ static int ram_save_init_globals(void)
*/
static int ram_save_setup(QEMUFile *f, void *opaque)
{
RAMState *rs = opaque;
RAMBlock *block;
/* migration has already setup the bitmap, reuse it. */
if (!migration_in_colo_state()) {
if (ram_save_init_globals() < 0) {
if (ram_save_init_globals(rs) < 0) {
return -1;
}
}
@ -2107,14 +2130,15 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
*/
static int ram_save_iterate(QEMUFile *f, void *opaque)
{
RAMState *rs = opaque;
int ret;
int i;
int64_t t0;
int done = 0;
rcu_read_lock();
if (ram_list.version != last_version) {
reset_ram_globals();
if (ram_list.version != rs->last_version) {
ram_state_reset(rs);
}
/* Read version before ram_list.blocks */
@ -2127,7 +2151,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
while ((ret = qemu_file_rate_limit(f)) == 0) {
int pages;
pages = ram_find_and_save_block(f, false, &bytes_transferred);
pages = ram_find_and_save_block(rs, f, false, &bytes_transferred);
/* no more pages to sent */
if (pages == 0) {
done = 1;
@ -2181,6 +2205,8 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
*/
static int ram_save_complete(QEMUFile *f, void *opaque)
{
RAMState *rs = opaque;
rcu_read_lock();
if (!migration_in_postcopy(migrate_get_current())) {
@ -2195,7 +2221,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
while (true) {
int pages;
pages = ram_find_and_save_block(f, !migration_in_colo_state(),
pages = ram_find_and_save_block(rs, f, !migration_in_colo_state(),
&bytes_transferred);
/* no more blocks to sent */
if (pages == 0) {
@ -2779,5 +2805,5 @@ static SaveVMHandlers savevm_ram_handlers = {
void ram_mig_init(void)
{
qemu_mutex_init(&XBZRLE.lock);
register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, &ram_state);
}