From ce5997b8161909161f443228256bdb643c81abcf Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Tue, 28 Jul 2015 15:46:47 +0200
Subject: [PATCH 02/28] migration: move ram stuff to migration/ram
Message-id: <1438098431-30847-3-git-send-email-quintela@redhat.com>
Patchwork-id: 67160
O-Subject: [RHEL-7 qemu-kvm PATCH 02/26] migration: move ram stuff to migration/ram
Bugzilla: 580006
RH-Acked-by: Alex Williamson <alex.williamson@redhat.com>
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
For historic reasons, ram migration have been on arch_init.c. Just
split it into migration/ram.c, the same that happened with block.c.
There is only code movement, no changes altogether.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 56e93d26b85bac76b93211393163c2ebcdee9481)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Conflicts:
Makefile.target
arch_init.c
include/migration/migration.h
No compression code.
Signed-off-by: Juan Quintela <quintela@trasno.org>
---
MAINTAINERS | 1 -
Makefile.target | 1 +
arch_init.c | 1170 ---------------------------------------
include/migration/migration.h | 1 +
include/sysemu/arch_init.h | 1 -
migration/ram.c | 1220 +++++++++++++++++++++++++++++++++++++++++
trace-events | 2 +-
7 files changed, 1223 insertions(+), 1173 deletions(-)
create mode 100644 migration/ram.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a8ec9be..ec1d6af 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -985,7 +985,6 @@ S: Maintained
F: include/migration/
F: migration/
F: savevm.c
-F: arch_init.c
F: scripts/vmstate-static-checker.py
F: tests/vmstate-static-checker-data/
diff --git a/Makefile.target b/Makefile.target
index 2262d89..729ac57 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -134,6 +134,7 @@ obj-$(CONFIG_KVM) += kvm-all.o
obj-y += memory.o savevm.o cputlb.o
obj-y += memory_mapping.o
obj-y += dump.o
+obj-y += migration/ram.o
LIBS+=$(libs_softmmu)
# xen support
diff --git a/arch_init.c b/arch_init.c
index 4ae486f..2f38359 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -54,14 +54,6 @@
#include "qemu/host-utils.h"
#include "qemu/rcu_queue.h"
-#ifdef DEBUG_ARCH_INIT
-#define DPRINTF(fmt, ...) \
- do { fprintf(stdout, "arch_init: " fmt, ## __VA_ARGS__); } while (0)
-#else
-#define DPRINTF(fmt, ...) \
- do { } while (0)
-#endif
-
#ifdef TARGET_SPARC
int graphic_width = 1024;
int graphic_height = 768;
@@ -110,23 +102,6 @@ int graphic_depth = 32;
#endif
const uint32_t arch_type = QEMU_ARCH;
-static bool mig_throttle_on;
-static int dirty_rate_high_cnt;
-static void check_guest_throttling(void);
-
-static uint64_t bitmap_sync_count;
-
-/***********************************************************/
-/* ram save/restore */
-
-#define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */
-#define RAM_SAVE_FLAG_COMPRESS 0x02
-#define RAM_SAVE_FLAG_MEM_SIZE 0x04
-#define RAM_SAVE_FLAG_PAGE 0x08
-#define RAM_SAVE_FLAG_EOS 0x10
-#define RAM_SAVE_FLAG_CONTINUE 0x20
-#define RAM_SAVE_FLAG_XBZRLE 0x40
-/* 0x80 is reserved in migration.h start with 0x100 next */
static struct defconfig_file {
const char *filename;
@@ -138,8 +113,6 @@ static struct defconfig_file {
{ NULL }, /* end of list */
};
-static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
-
int qemu_read_default_config_files(bool userconfig)
{
int ret;
@@ -158,1100 +131,6 @@ int qemu_read_default_config_files(bool userconfig)
return 0;
}
-static inline bool is_zero_range(uint8_t *p, uint64_t size)
-{
- return buffer_find_nonzero_offset(p, size) == size;
-}
-
-/* struct contains XBZRLE cache and a static page
- used by the compression */
-static struct {
- /* buffer used for XBZRLE encoding */
- uint8_t *encoded_buf;
- /* buffer for storing page content */
- uint8_t *current_buf;
- /* Cache for XBZRLE, Protected by lock. */
- PageCache *cache;
- QemuMutex lock;
-} XBZRLE;
-
-/* buffer used for XBZRLE decoding */
-static uint8_t *xbzrle_decoded_buf;
-
-static void XBZRLE_cache_lock(void)
-{
- if (migrate_use_xbzrle())
- qemu_mutex_lock(&XBZRLE.lock);
-}
-
-static void XBZRLE_cache_unlock(void)
-{
- if (migrate_use_xbzrle())
- qemu_mutex_unlock(&XBZRLE.lock);
-}
-
-/*
- * called from qmp_migrate_set_cache_size in main thread, possibly while
- * a migration is in progress.
- * A running migration maybe using the cache and might finish during this
- * call, hence changes to the cache are protected by XBZRLE.lock().
- */
-int64_t xbzrle_cache_resize(int64_t new_size)
-{
- PageCache *new_cache;
- int64_t ret;
-
- if (new_size < TARGET_PAGE_SIZE) {
- return -1;
- }
-
- XBZRLE_cache_lock();
-
- if (XBZRLE.cache != NULL) {
- if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
- goto out_new_size;
- }
- new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
- TARGET_PAGE_SIZE);
- if (!new_cache) {
- error_report("Error creating cache");
- ret = -1;
- goto out;
- }
-
- cache_fini(XBZRLE.cache);
- XBZRLE.cache = new_cache;
- }
-
-out_new_size:
- ret = pow2floor(new_size);
-out:
- XBZRLE_cache_unlock();
- return ret;
-}
-
-/* accounting for migration statistics */
-typedef struct AccountingInfo {
- uint64_t dup_pages;
- uint64_t skipped_pages;
- uint64_t norm_pages;
- uint64_t iterations;
- uint64_t xbzrle_bytes;
- uint64_t xbzrle_pages;
- uint64_t xbzrle_cache_miss;
- double xbzrle_cache_miss_rate;
- uint64_t xbzrle_overflows;
-} AccountingInfo;
-
-static AccountingInfo acct_info;
-
-static void acct_clear(void)
-{
- memset(&acct_info, 0, sizeof(acct_info));
-}
-
-uint64_t dup_mig_bytes_transferred(void)
-{
- return acct_info.dup_pages * TARGET_PAGE_SIZE;
-}
-
-uint64_t dup_mig_pages_transferred(void)
-{
- return acct_info.dup_pages;
-}
-
-uint64_t skipped_mig_bytes_transferred(void)
-{
- return acct_info.skipped_pages * TARGET_PAGE_SIZE;
-}
-
-uint64_t skipped_mig_pages_transferred(void)
-{
- return acct_info.skipped_pages;
-}
-
-uint64_t norm_mig_bytes_transferred(void)
-{
- return acct_info.norm_pages * TARGET_PAGE_SIZE;
-}
-
-uint64_t norm_mig_pages_transferred(void)
-{
- return acct_info.norm_pages;
-}
-
-uint64_t xbzrle_mig_bytes_transferred(void)
-{
- return acct_info.xbzrle_bytes;
-}
-
-uint64_t xbzrle_mig_pages_transferred(void)
-{
- return acct_info.xbzrle_pages;
-}
-
-uint64_t xbzrle_mig_pages_cache_miss(void)
-{
- return acct_info.xbzrle_cache_miss;
-}
-
-double xbzrle_mig_cache_miss_rate(void)
-{
- return acct_info.xbzrle_cache_miss_rate;
-}
-
-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 unsigned long *migration_bitmap;
-static uint64_t migration_dirty_pages;
-static uint32_t last_version;
-static bool ram_bulk_stage;
-
-/**
- * save_page_header: Write page header to wire
- *
- * If this is the 1st block, it also writes the block identification
- *
- * Returns: Number of bytes written
- *
- * @f: QEMUFile where to send the data
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * in the lower bits, it contains flags
- */
-static size_t save_page_header(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
-{
- size_t size;
-
- qemu_put_be64(f, offset);
- size = 8;
-
- if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
- qemu_put_byte(f, strlen(block->idstr));
- qemu_put_buffer(f, (uint8_t *)block->idstr,
- strlen(block->idstr));
- size += 1 + strlen(block->idstr);
- }
- return size;
-}
-
-/* Update the xbzrle cache to reflect a page that's been sent as all 0.
- * The important thing is that a stale (not-yet-0'd) page be replaced
- * by the new data.
- * 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)
-{
- if (ram_bulk_stage || !migrate_use_xbzrle()) {
- return;
- }
-
- /* We don't care if this fails to allocate a new cache page
- * as long as it updated an old one */
- cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
- bitmap_sync_count);
-}
-
-#define ENCODING_FLAG_XBZRLE 0x1
-
-/**
- * save_xbzrle_page: compress and send current page
- *
- * Returns: 1 means that we wrote the page
- * 0 means that page is identical to the one already sent
- * -1 means that xbzrle would be longer than normal
- *
- * @f: QEMUFile where to send the data
- * @current_data:
- * @current_addr:
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * @last_stage: if we are at the completion stage
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
- ram_addr_t current_addr, RAMBlock *block,
- ram_addr_t offset, bool last_stage,
- uint64_t *bytes_transferred)
-{
- int encoded_len = 0, bytes_xbzrle;
- uint8_t *prev_cached_page;
-
- if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
- acct_info.xbzrle_cache_miss++;
- if (!last_stage) {
- if (cache_insert(XBZRLE.cache, current_addr, *current_data,
- bitmap_sync_count) == -1) {
- return -1;
- } else {
- /* update *current_data when the page has been
- inserted into cache */
- *current_data = get_cached_data(XBZRLE.cache, current_addr);
- }
- }
- return -1;
- }
-
- prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
-
- /* save current buffer into memory */
- memcpy(XBZRLE.current_buf, *current_data, TARGET_PAGE_SIZE);
-
- /* XBZRLE encoding (if there is no overflow) */
- encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
- TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
- TARGET_PAGE_SIZE);
- if (encoded_len == 0) {
- DPRINTF("Skipping unmodified page\n");
- return 0;
- } else if (encoded_len == -1) {
- DPRINTF("Overflow\n");
- acct_info.xbzrle_overflows++;
- /* update data in the cache */
- if (!last_stage) {
- memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
- *current_data = prev_cached_page;
- }
- return -1;
- }
-
- /* we need to update the data in the cache, in order to get the same data */
- if (!last_stage) {
- memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
- }
-
- /* Send XBZRLE based compressed page */
- bytes_xbzrle = save_page_header(f, block, offset | RAM_SAVE_FLAG_XBZRLE);
- qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
- qemu_put_be16(f, encoded_len);
- qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
- bytes_xbzrle += encoded_len + 1 + 2;
- acct_info.xbzrle_pages++;
- acct_info.xbzrle_bytes += bytes_xbzrle;
- *bytes_transferred += bytes_xbzrle;
-
- return 1;
-}
-
-static inline
-ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
- ram_addr_t start)
-{
- unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
- unsigned long nr = base + (start >> TARGET_PAGE_BITS);
- uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
- unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
-
- unsigned long next;
-
- if (ram_bulk_stage && nr > base) {
- next = nr + 1;
- } else {
- next = find_next_bit(migration_bitmap, size, nr);
- }
-
- if (next < size) {
- clear_bit(next, migration_bitmap);
- migration_dirty_pages--;
- }
- return (next - base) << TARGET_PAGE_BITS;
-}
-
-static inline bool migration_bitmap_set_dirty(ram_addr_t addr)
-{
- bool ret;
- int nr = addr >> TARGET_PAGE_BITS;
-
- ret = test_and_set_bit(nr, migration_bitmap);
-
- if (!ret) {
- migration_dirty_pages++;
- }
- return ret;
-}
-
-static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
-{
- ram_addr_t addr;
- unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
-
- /* start address is aligned at the start of a word? */
- if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {
- int k;
- int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
- unsigned long *src = ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION];
-
- for (k = page; k < page + nr; k++) {
- if (src[k]) {
- unsigned long new_dirty;
- new_dirty = ~migration_bitmap[k];
- migration_bitmap[k] |= src[k];
- new_dirty &= src[k];
- migration_dirty_pages += ctpopl(new_dirty);
- src[k] = 0;
- }
- }
- } else {
- for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
- if (cpu_physical_memory_get_dirty(start + addr,
- TARGET_PAGE_SIZE,
- DIRTY_MEMORY_MIGRATION)) {
- cpu_physical_memory_reset_dirty(start + addr,
- TARGET_PAGE_SIZE,
- DIRTY_MEMORY_MIGRATION);
- migration_bitmap_set_dirty(start + addr);
- }
- }
- }
-}
-
-
-/* Fix me: there are too many global variables used in migration process. */
-static int64_t start_time;
-static int64_t bytes_xfer_prev;
-static int64_t num_dirty_pages_period;
-static uint64_t xbzrle_cache_miss_prev;
-static uint64_t iterations_prev;
-
-static void migration_bitmap_sync_init(void)
-{
- start_time = 0;
- bytes_xfer_prev = 0;
- num_dirty_pages_period = 0;
- xbzrle_cache_miss_prev = 0;
- iterations_prev = 0;
-}
-
-/* Called with iothread lock held, to protect ram_list.dirty_memory[] */
-static void migration_bitmap_sync(void)
-{
- RAMBlock *block;
- uint64_t num_dirty_pages_init = migration_dirty_pages;
- MigrationState *s = migrate_get_current();
- int64_t end_time;
- int64_t bytes_xfer_now;
-
- bitmap_sync_count++;
-
- if (!bytes_xfer_prev) {
- bytes_xfer_prev = ram_bytes_transferred();
- }
-
- if (!start_time) {
- start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
- }
-
- trace_migration_bitmap_sync_start();
- address_space_sync_dirty_bitmap(&address_space_memory);
-
- rcu_read_lock();
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
- }
- rcu_read_unlock();
-
- trace_migration_bitmap_sync_end(migration_dirty_pages
- - num_dirty_pages_init);
- num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;
- end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
-
- /* more than 1 second = 1000 millisecons */
- if (end_time > start_time + 1000) {
- if (migrate_auto_converge()) {
- /* The following detection logic can be refined later. For now:
- Check to see if the dirtied bytes is 50% more than the approx.
- amount of bytes that just got transferred since the last time we
- were in this routine. If that happens >N times (for now N==4)
- we turn on the throttle down logic */
- bytes_xfer_now = ram_bytes_transferred();
- if (s->dirty_pages_rate &&
- (num_dirty_pages_period * TARGET_PAGE_SIZE >
- (bytes_xfer_now - bytes_xfer_prev)/2) &&
- (dirty_rate_high_cnt++ > 4)) {
- trace_migration_throttle();
- mig_throttle_on = true;
- dirty_rate_high_cnt = 0;
- }
- bytes_xfer_prev = bytes_xfer_now;
- } else {
- mig_throttle_on = false;
- }
- if (migrate_use_xbzrle()) {
- if (iterations_prev != acct_info.iterations) {
- acct_info.xbzrle_cache_miss_rate =
- (double)(acct_info.xbzrle_cache_miss -
- xbzrle_cache_miss_prev) /
- (acct_info.iterations - iterations_prev);
- }
- iterations_prev = acct_info.iterations;
- xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
- }
- s->dirty_pages_rate = num_dirty_pages_period * 1000
- / (end_time - start_time);
- s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
- start_time = end_time;
- num_dirty_pages_period = 0;
- s->dirty_sync_count = bitmap_sync_count;
- }
-}
-
-/**
- * ram_save_page: Send the given page to the stream
- *
- * Returns: Number of pages written.
- *
- * @f: QEMUFile where to send the data
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * @last_stage: if we are at the completion stage
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
- bool last_stage, uint64_t *bytes_transferred)
-{
- int pages = -1;
- uint64_t bytes_xmit;
- ram_addr_t current_addr;
- MemoryRegion *mr = block->mr;
- uint8_t *p;
- int ret;
- bool send_async = true;
-
- p = memory_region_get_ram_ptr(mr) + offset;
-
- /* In doubt sent page as normal */
- bytes_xmit = 0;
- ret = ram_control_save_page(f, block->offset,
- offset, TARGET_PAGE_SIZE, &bytes_xmit);
- if (bytes_xmit) {
- *bytes_transferred += bytes_xmit;
- pages = 1;
- }
-
- XBZRLE_cache_lock();
-
- current_addr = block->offset + offset;
-
- if (block == last_sent_block) {
- offset |= RAM_SAVE_FLAG_CONTINUE;
- }
- if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
- if (ret != RAM_SAVE_CONTROL_DELAYED) {
- if (bytes_xmit > 0) {
- acct_info.norm_pages++;
- } else if (bytes_xmit == 0) {
- acct_info.dup_pages++;
- }
- }
- } else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
- acct_info.dup_pages++;
- *bytes_transferred += save_page_header(f, block,
- offset | RAM_SAVE_FLAG_COMPRESS);
- qemu_put_byte(f, 0);
- *bytes_transferred += 1;
- pages = 1;
- /* Must let xbzrle know, otherwise a previous (now 0'd) cached
- * page would be stale
- */
- xbzrle_cache_zero_page(current_addr);
- } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
- pages = save_xbzrle_page(f, &p, current_addr, block,
- offset, last_stage, bytes_transferred);
- if (!last_stage) {
- /* Can't send this cached data async, since the cache page
- * might get updated before it gets to the wire
- */
- send_async = false;
- }
- }
-
- /* XBZRLE overflow or normal page */
- if (pages == -1) {
- *bytes_transferred += save_page_header(f, block,
- offset | RAM_SAVE_FLAG_PAGE);
- if (send_async) {
- qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
- } else {
- qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
- }
- *bytes_transferred += TARGET_PAGE_SIZE;
- pages = 1;
- acct_info.norm_pages++;
- }
-
- XBZRLE_cache_unlock();
-
- return pages;
-}
-
-/**
- * ram_find_and_save_block: Finds a dirty page and sends it to f
- *
- * Called within an RCU critical section.
- *
- * Returns: The number of pages written
- * 0 means no dirty pages
- *
- * @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
- */
-
-static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
- uint64_t *bytes_transferred)
-{
- RAMBlock *block = last_seen_block;
- ram_addr_t offset = last_offset;
- bool complete_round = false;
- int pages = 0;
- MemoryRegion *mr;
-
- if (!block)
- block = QLIST_FIRST_RCU(&ram_list.blocks);
-
- while (true) {
- mr = block->mr;
- offset = migration_bitmap_find_and_reset_dirty(mr, offset);
- if (complete_round && block == last_seen_block &&
- offset >= last_offset) {
- break;
- }
- if (offset >= block->used_length) {
- offset = 0;
- block = QLIST_NEXT_RCU(block, next);
- if (!block) {
- block = QLIST_FIRST_RCU(&ram_list.blocks);
- complete_round = true;
- ram_bulk_stage = false;
- }
- } else {
- pages = ram_save_page(f, block, offset, last_stage,
- bytes_transferred);
-
- /* if page is unmodified, continue to the next */
- if (pages > 0) {
- last_sent_block = block;
- break;
- }
- }
- }
-
- last_seen_block = block;
- last_offset = offset;
-
- return pages;
-}
-
-static uint64_t bytes_transferred;
-
-void acct_update_position(QEMUFile *f, size_t size, bool zero)
-{
- uint64_t pages = size / TARGET_PAGE_SIZE;
- if (zero) {
- acct_info.dup_pages += pages;
- } else {
- acct_info.norm_pages += pages;
- bytes_transferred += size;
- qemu_update_position(f, size);
- }
-}
-
-static ram_addr_t ram_save_remaining(void)
-{
- return migration_dirty_pages;
-}
-
-uint64_t ram_bytes_remaining(void)
-{
- return ram_save_remaining() * TARGET_PAGE_SIZE;
-}
-
-uint64_t ram_bytes_transferred(void)
-{
- return bytes_transferred;
-}
-
-uint64_t ram_bytes_total(void)
-{
- RAMBlock *block;
- uint64_t total = 0;
-
- rcu_read_lock();
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
- total += block->used_length;
- rcu_read_unlock();
- return total;
-}
-
-void free_xbzrle_decoded_buf(void)
-{
- g_free(xbzrle_decoded_buf);
- xbzrle_decoded_buf = NULL;
-}
-
-static void migration_end(void)
-{
- if (migration_bitmap) {
- memory_global_dirty_log_stop();
- g_free(migration_bitmap);
- migration_bitmap = NULL;
- }
-
- XBZRLE_cache_lock();
- if (XBZRLE.cache) {
- cache_fini(XBZRLE.cache);
- g_free(XBZRLE.encoded_buf);
- g_free(XBZRLE.current_buf);
- XBZRLE.cache = NULL;
- XBZRLE.encoded_buf = NULL;
- XBZRLE.current_buf = NULL;
- }
- XBZRLE_cache_unlock();
-}
-
-static void ram_migration_cancel(void *opaque)
-{
- migration_end();
-}
-
-static void reset_ram_globals(void)
-{
- last_seen_block = NULL;
- last_sent_block = NULL;
- last_offset = 0;
- last_version = ram_list.version;
- ram_bulk_stage = true;
-}
-
-#define MAX_WAIT 50 /* ms, half buffered_file limit */
-
-
-/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
- * long-running RCU critical section. When rcu-reclaims in the code
- * start to become numerous it will be necessary to reduce the
- * granularity of these critical sections.
- */
-
-static int ram_save_setup(QEMUFile *f, void *opaque)
-{
- RAMBlock *block;
- int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
-
- mig_throttle_on = false;
- dirty_rate_high_cnt = 0;
- bitmap_sync_count = 0;
- migration_bitmap_sync_init();
-
- if (migrate_use_xbzrle()) {
- XBZRLE_cache_lock();
- XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
- TARGET_PAGE_SIZE,
- TARGET_PAGE_SIZE);
- if (!XBZRLE.cache) {
- XBZRLE_cache_unlock();
- error_report("Error creating cache");
- return -1;
- }
- XBZRLE_cache_unlock();
-
- /* We prefer not to abort if there is no memory */
- XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
- if (!XBZRLE.encoded_buf) {
- error_report("Error allocating encoded_buf");
- return -1;
- }
-
- XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
- if (!XBZRLE.current_buf) {
- error_report("Error allocating current_buf");
- g_free(XBZRLE.encoded_buf);
- XBZRLE.encoded_buf = NULL;
- return -1;
- }
-
- acct_clear();
- }
-
- /* iothread lock needed for ram_list.dirty_memory[] */
- qemu_mutex_lock_iothread();
- qemu_mutex_lock_ramlist();
- rcu_read_lock();
- bytes_transferred = 0;
- reset_ram_globals();
-
- ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
- migration_bitmap = bitmap_new(ram_bitmap_pages);
- bitmap_set(migration_bitmap, 0, ram_bitmap_pages);
-
- /*
- * Count the total number of pages used by ram blocks not including any
- * gaps due to alignment or unplugs.
- */
- migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
-
- memory_global_dirty_log_start();
- migration_bitmap_sync();
- qemu_mutex_unlock_ramlist();
- qemu_mutex_unlock_iothread();
-
- qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
-
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- qemu_put_byte(f, strlen(block->idstr));
- qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
- qemu_put_be64(f, block->used_length);
- }
-
- rcu_read_unlock();
-
- ram_control_before_iterate(f, RAM_CONTROL_SETUP);
- ram_control_after_iterate(f, RAM_CONTROL_SETUP);
-
- qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
-
- return 0;
-}
-
-static int ram_save_iterate(QEMUFile *f, void *opaque)
-{
- int ret;
- int i;
- int64_t t0;
- int pages_sent = 0;
-
- rcu_read_lock();
- if (ram_list.version != last_version) {
- reset_ram_globals();
- }
-
- /* Read version before ram_list.blocks */
- smp_rmb();
-
- ram_control_before_iterate(f, RAM_CONTROL_ROUND);
-
- t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
- i = 0;
- while ((ret = qemu_file_rate_limit(f)) == 0) {
- int pages;
-
- pages = ram_find_and_save_block(f, false, &bytes_transferred);
- /* no more pages to sent */
- if (pages == 0) {
- break;
- }
- pages_sent += pages;
- acct_info.iterations++;
- check_guest_throttling();
- /* we want to check in the 1st loop, just in case it was the 1st time
- and we had to sync the dirty bitmap.
- qemu_get_clock_ns() is a bit expensive, so we only check each some
- iterations
- */
- if ((i & 63) == 0) {
- uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
- if (t1 > MAX_WAIT) {
- DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",
- t1, i);
- break;
- }
- }
- i++;
- }
- rcu_read_unlock();
-
- /*
- * Must occur before EOS (or any QEMUFile operation)
- * because of RDMA protocol.
- */
- ram_control_after_iterate(f, RAM_CONTROL_ROUND);
-
- qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
- bytes_transferred += 8;
-
- ret = qemu_file_get_error(f);
- if (ret < 0) {
- return ret;
- }
-
- return pages_sent;
-}
-
-/* Called with iothread lock */
-static int ram_save_complete(QEMUFile *f, void *opaque)
-{
- rcu_read_lock();
-
- migration_bitmap_sync();
-
- ram_control_before_iterate(f, RAM_CONTROL_FINISH);
-
- /* try transferring iterative blocks of memory */
-
- /* flush all remaining blocks regardless of rate limiting */
- while (true) {
- int pages;
-
- pages = ram_find_and_save_block(f, true, &bytes_transferred);
- /* no more blocks to sent */
- if (pages == 0) {
- break;
- }
- }
-
- ram_control_after_iterate(f, RAM_CONTROL_FINISH);
- migration_end();
-
- rcu_read_unlock();
- qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
-
- return 0;
-}
-
-static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
-{
- uint64_t remaining_size;
-
- remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
-
- if (remaining_size < max_size) {
- qemu_mutex_lock_iothread();
- rcu_read_lock();
- migration_bitmap_sync();
- rcu_read_unlock();
- qemu_mutex_unlock_iothread();
- remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
- }
- return remaining_size;
-}
-
-static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
-{
- unsigned int xh_len;
- int xh_flags;
-
- if (!xbzrle_decoded_buf) {
- xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
- }
-
- /* extract RLE header */
- xh_flags = qemu_get_byte(f);
- xh_len = qemu_get_be16(f);
-
- if (xh_flags != ENCODING_FLAG_XBZRLE) {
- error_report("Failed to load XBZRLE page - wrong compression!");
- return -1;
- }
-
- if (xh_len > TARGET_PAGE_SIZE) {
- error_report("Failed to load XBZRLE page - len overflow!");
- return -1;
- }
- /* load data and decode */
- qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
-
- /* decode RLE */
- if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
- TARGET_PAGE_SIZE) == -1) {
- error_report("Failed to load XBZRLE page - decode error!");
- return -1;
- }
-
- return 0;
-}
-
-/* Must be called from within a rcu critical section.
- * Returns a pointer from within the RCU-protected ram_list.
- */
-static inline void *host_from_stream_offset(QEMUFile *f,
- ram_addr_t offset,
- int flags)
-{
- static RAMBlock *block = NULL;
- char id[256];
- uint8_t len;
-
- if (flags & RAM_SAVE_FLAG_CONTINUE) {
- if (!block || block->max_length <= offset) {
- error_report("Ack, bad migration stream!");
- return NULL;
- }
-
- return memory_region_get_ram_ptr(block->mr) + offset;
- }
-
- len = qemu_get_byte(f);
- qemu_get_buffer(f, (uint8_t *)id, len);
- id[len] = 0;
-
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- if (!strncmp(id, block->idstr, sizeof(id)) &&
- block->max_length > offset) {
- return memory_region_get_ram_ptr(block->mr) + offset;
- }
- }
-
- error_report("Can't find block %s!", id);
- return NULL;
-}
-
-/*
- * If a page (or a whole RDMA chunk) has been
- * determined to be zero, then zap it.
- */
-void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
-{
- if (ch != 0 || !is_zero_range(host, size)) {
- memset(host, ch, size);
- }
-}
-
-static int ram_load(QEMUFile *f, void *opaque, int version_id)
-{
- int flags = 0, ret = 0;
- static uint64_t seq_iter;
-
- seq_iter++;
-
- if (version_id != 4) {
- ret = -EINVAL;
- }
-
- /* This RCU critical section can be very long running.
- * When RCU reclaims in the code start to become numerous,
- * it will be necessary to reduce the granularity of this
- * critical section.
- */
- rcu_read_lock();
- while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
- ram_addr_t addr, total_ram_bytes;
- void *host;
- uint8_t ch;
-
- addr = qemu_get_be64(f);
- flags = addr & ~TARGET_PAGE_MASK;
- addr &= TARGET_PAGE_MASK;
-
- switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
- case RAM_SAVE_FLAG_MEM_SIZE:
- /* Synchronize RAM block list */
- total_ram_bytes = addr;
- while (!ret && total_ram_bytes) {
- RAMBlock *block;
- uint8_t len;
- char id[256];
- ram_addr_t length;
-
- len = qemu_get_byte(f);
- qemu_get_buffer(f, (uint8_t *)id, len);
- id[len] = 0;
- length = qemu_get_be64(f);
-
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- if (!strncmp(id, block->idstr, sizeof(id))) {
- if (length != block->used_length) {
- Error *local_err = NULL;
-
- ret = qemu_ram_resize(block->offset, length, &local_err);
- if (local_err) {
- error_report_err(local_err);
- }
- }
- ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
- block->idstr);
- break;
- }
- }
-
- if (!block) {
- error_report("Unknown ramblock \"%s\", cannot "
- "accept migration", id);
- ret = -EINVAL;
- }
-
- total_ram_bytes -= length;
- }
- break;
- case RAM_SAVE_FLAG_COMPRESS:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
- ch = qemu_get_byte(f);
- ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
- break;
- case RAM_SAVE_FLAG_PAGE:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
- qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
- break;
- case RAM_SAVE_FLAG_XBZRLE:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
- if (load_xbzrle(f, addr, host) < 0) {
- error_report("Failed to decompress XBZRLE page at "
- RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
- break;
- case RAM_SAVE_FLAG_EOS:
- /* normal exit */
- break;
- default:
- if (flags & RAM_SAVE_FLAG_HOOK) {
- ram_control_load_hook(f, RAM_CONTROL_HOOK, NULL);
- } else {
- error_report("Unknown combination of migration flags: %#x",
- flags);
- ret = -EINVAL;
- }
- }
- if (!ret) {
- ret = qemu_file_get_error(f);
- }
- }
-
- rcu_read_unlock();
- DPRINTF("Completed load of VM with exit code %d seq iteration "
- "%" PRIu64 "\n", ret, seq_iter);
- return ret;
-}
-
-static SaveVMHandlers savevm_ram_handlers = {
- .save_live_setup = ram_save_setup,
- .save_live_iterate = ram_save_iterate,
- .save_live_complete = ram_save_complete,
- .save_live_pending = ram_save_pending,
- .load_state = ram_load,
- .cancel = ram_migration_cancel,
-};
-
-void ram_mig_init(void)
-{
- qemu_mutex_init(&XBZRLE.lock);
- register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
-}
-
struct soundhw {
const char *name;
const char *descr;
@@ -1451,52 +330,3 @@ TargetInfo *qmp_query_target(Error **errp)
return info;
}
-
-/* Stub function that's gets run on the vcpu when its brought out of the
- VM to run inside qemu via async_run_on_cpu()*/
-static void mig_sleep_cpu(void *opq)
-{
- qemu_mutex_unlock_iothread();
- g_usleep(30*1000);
- qemu_mutex_lock_iothread();
-}
-
-/* To reduce the dirty rate explicitly disallow the VCPUs from spending
- much time in the VM. The migration thread will try to catchup.
- Workload will experience a performance drop.
-*/
-static void mig_throttle_guest_down(void)
-{
- CPUState *cpu;
-
- qemu_mutex_lock_iothread();
- CPU_FOREACH(cpu) {
- async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
- }
- qemu_mutex_unlock_iothread();
-}
-
-static void check_guest_throttling(void)
-{
- static int64_t t0;
- int64_t t1;
-
- if (!mig_throttle_on) {
- return;
- }
-
- if (!t0) {
- t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
- return;
- }
-
- t1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-
- /* If it has been more than 40 ms since the last time the guest
- * was throttled then do it again.
- */
- if (40 < (t1-t0)/1000000) {
- mig_throttle_guest_down();
- t0 = t1;
- }
-}
diff --git a/include/migration/migration.h b/include/migration/migration.h
index b901d0f..b89d0b8 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -170,6 +170,7 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
ram_addr_t offset, size_t size,
uint64_t *bytes_sent);
+void ram_mig_init(void);
/*
* Disables a load of subsections that were added in 2.2/rh7.2 for backwards
diff --git a/include/sysemu/arch_init.h b/include/sysemu/arch_init.h
index 54b36c1..c38892f 100644
--- a/include/sysemu/arch_init.h
+++ b/include/sysemu/arch_init.h
@@ -30,7 +30,6 @@ extern const uint32_t arch_type;
void select_soundhw(const char *optarg);
void do_acpitable_option(const QemuOpts *opts);
void do_smbios_option(QemuOpts *opts);
-void ram_mig_init(void);
void cpudef_init(void);
void audio_init(void);
int kvm_available(void);
diff --git a/migration/ram.c b/migration/ram.c
new file mode 100644
index 0000000..8548d26
--- /dev/null
+++ b/migration/ram.c
@@ -0,0 +1,1220 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <stdint.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#ifndef _WIN32
+#include <sys/types.h>
+#include <sys/mman.h>
+#endif
+#include "config.h"
+#include "monitor/monitor.h"
+#include "sysemu/sysemu.h"
+#include "qemu/bitops.h"
+#include "qemu/bitmap.h"
+#include "hw/i386/pc.h"
+#include "hw/pci/pci.h"
+#include "hw/audio/audio.h"
+#include "migration/migration.h"
+#include "exec/address-spaces.h"
+#include "migration/page_cache.h"
+#include "qemu/config-file.h"
+#include "qemu/error-report.h"
+#include "qmp-commands.h"
+#include "trace.h"
+#include "exec/cpu-all.h"
+#include "exec/ram_addr.h"
+#include "qemu/host-utils.h"
+#include "qemu/rcu_queue.h"
+
+#ifdef DEBUG_MIGRATION_RAM
+#define DPRINTF(fmt, ...) \
+ do { fprintf(stdout, "migration_ram: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+ do { } while (0)
+#endif
+
+static bool mig_throttle_on;
+static int dirty_rate_high_cnt;
+static void check_guest_throttling(void);
+
+static uint64_t bitmap_sync_count;
+
+/***********************************************************/
+/* ram save/restore */
+
+#define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */
+#define RAM_SAVE_FLAG_COMPRESS 0x02
+#define RAM_SAVE_FLAG_MEM_SIZE 0x04
+#define RAM_SAVE_FLAG_PAGE 0x08
+#define RAM_SAVE_FLAG_EOS 0x10
+#define RAM_SAVE_FLAG_CONTINUE 0x20
+#define RAM_SAVE_FLAG_XBZRLE 0x40
+/* 0x80 is reserved in migration.h start with 0x100 next */
+
+static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
+
+static inline bool is_zero_range(uint8_t *p, uint64_t size)
+{
+ return buffer_find_nonzero_offset(p, size) == size;
+}
+
+/* struct contains XBZRLE cache and a static page
+ used by the compression */
+static struct {
+ /* buffer used for XBZRLE encoding */
+ uint8_t *encoded_buf;
+ /* buffer for storing page content */
+ uint8_t *current_buf;
+ /* Cache for XBZRLE, Protected by lock. */
+ PageCache *cache;
+ QemuMutex lock;
+} XBZRLE;
+
+/* buffer used for XBZRLE decoding */
+static uint8_t *xbzrle_decoded_buf;
+
+static void XBZRLE_cache_lock(void)
+{
+ if (migrate_use_xbzrle())
+ qemu_mutex_lock(&XBZRLE.lock);
+}
+
+static void XBZRLE_cache_unlock(void)
+{
+ if (migrate_use_xbzrle())
+ qemu_mutex_unlock(&XBZRLE.lock);
+}
+
+/*
+ * called from qmp_migrate_set_cache_size in main thread, possibly while
+ * a migration is in progress.
+ * A running migration maybe using the cache and might finish during this
+ * call, hence changes to the cache are protected by XBZRLE.lock().
+ */
+int64_t xbzrle_cache_resize(int64_t new_size)
+{
+ PageCache *new_cache;
+ int64_t ret;
+
+ if (new_size < TARGET_PAGE_SIZE) {
+ return -1;
+ }
+
+ XBZRLE_cache_lock();
+
+ if (XBZRLE.cache != NULL) {
+ if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
+ goto out_new_size;
+ }
+ new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
+ TARGET_PAGE_SIZE);
+ if (!new_cache) {
+ error_report("Error creating cache");
+ ret = -1;
+ goto out;
+ }
+
+ cache_fini(XBZRLE.cache);
+ XBZRLE.cache = new_cache;
+ }
+
+out_new_size:
+ ret = pow2floor(new_size);
+out:
+ XBZRLE_cache_unlock();
+ return ret;
+}
+
+/* accounting for migration statistics */
+typedef struct AccountingInfo {
+ uint64_t dup_pages;
+ uint64_t skipped_pages;
+ uint64_t norm_pages;
+ uint64_t iterations;
+ uint64_t xbzrle_bytes;
+ uint64_t xbzrle_pages;
+ uint64_t xbzrle_cache_miss;
+ double xbzrle_cache_miss_rate;
+ uint64_t xbzrle_overflows;
+} AccountingInfo;
+
+static AccountingInfo acct_info;
+
+static void acct_clear(void)
+{
+ memset(&acct_info, 0, sizeof(acct_info));
+}
+
+uint64_t dup_mig_bytes_transferred(void)
+{
+ return acct_info.dup_pages * TARGET_PAGE_SIZE;
+}
+
+uint64_t dup_mig_pages_transferred(void)
+{
+ return acct_info.dup_pages;
+}
+
+uint64_t skipped_mig_bytes_transferred(void)
+{
+ return acct_info.skipped_pages * TARGET_PAGE_SIZE;
+}
+
+uint64_t skipped_mig_pages_transferred(void)
+{
+ return acct_info.skipped_pages;
+}
+
+uint64_t norm_mig_bytes_transferred(void)
+{
+ return acct_info.norm_pages * TARGET_PAGE_SIZE;
+}
+
+uint64_t norm_mig_pages_transferred(void)
+{
+ return acct_info.norm_pages;
+}
+
+uint64_t xbzrle_mig_bytes_transferred(void)
+{
+ return acct_info.xbzrle_bytes;
+}
+
+uint64_t xbzrle_mig_pages_transferred(void)
+{
+ return acct_info.xbzrle_pages;
+}
+
+uint64_t xbzrle_mig_pages_cache_miss(void)
+{
+ return acct_info.xbzrle_cache_miss;
+}
+
+double xbzrle_mig_cache_miss_rate(void)
+{
+ return acct_info.xbzrle_cache_miss_rate;
+}
+
+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 unsigned long *migration_bitmap;
+static uint64_t migration_dirty_pages;
+static uint32_t last_version;
+static bool ram_bulk_stage;
+
+/**
+ * save_page_header: Write page header to wire
+ *
+ * If this is the 1st block, it also writes the block identification
+ *
+ * Returns: Number of bytes written
+ *
+ * @f: QEMUFile where to send the data
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * in the lower bits, it contains flags
+ */
+static size_t save_page_header(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
+{
+ size_t size;
+
+ qemu_put_be64(f, offset);
+ size = 8;
+
+ if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
+ qemu_put_byte(f, strlen(block->idstr));
+ qemu_put_buffer(f, (uint8_t *)block->idstr,
+ strlen(block->idstr));
+ size += 1 + strlen(block->idstr);
+ }
+ return size;
+}
+
+/* Update the xbzrle cache to reflect a page that's been sent as all 0.
+ * The important thing is that a stale (not-yet-0'd) page be replaced
+ * by the new data.
+ * 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)
+{
+ if (ram_bulk_stage || !migrate_use_xbzrle()) {
+ return;
+ }
+
+ /* We don't care if this fails to allocate a new cache page
+ * as long as it updated an old one */
+ cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
+ bitmap_sync_count);
+}
+
+#define ENCODING_FLAG_XBZRLE 0x1
+
+/**
+ * save_xbzrle_page: compress and send current page
+ *
+ * Returns: 1 means that we wrote the page
+ * 0 means that page is identical to the one already sent
+ * -1 means that xbzrle would be longer than normal
+ *
+ * @f: QEMUFile where to send the data
+ * @current_data:
+ * @current_addr:
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
+ ram_addr_t current_addr, RAMBlock *block,
+ ram_addr_t offset, bool last_stage,
+ uint64_t *bytes_transferred)
+{
+ int encoded_len = 0, bytes_xbzrle;
+ uint8_t *prev_cached_page;
+
+ if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
+ acct_info.xbzrle_cache_miss++;
+ if (!last_stage) {
+ if (cache_insert(XBZRLE.cache, current_addr, *current_data,
+ bitmap_sync_count) == -1) {
+ return -1;
+ } else {
+ /* update *current_data when the page has been
+ inserted into cache */
+ *current_data = get_cached_data(XBZRLE.cache, current_addr);
+ }
+ }
+ return -1;
+ }
+
+ prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
+
+ /* save current buffer into memory */
+ memcpy(XBZRLE.current_buf, *current_data, TARGET_PAGE_SIZE);
+
+ /* XBZRLE encoding (if there is no overflow) */
+ encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
+ TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
+ TARGET_PAGE_SIZE);
+ if (encoded_len == 0) {
+ DPRINTF("Skipping unmodified page\n");
+ return 0;
+ } else if (encoded_len == -1) {
+ DPRINTF("Overflow\n");
+ acct_info.xbzrle_overflows++;
+ /* update data in the cache */
+ if (!last_stage) {
+ memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
+ *current_data = prev_cached_page;
+ }
+ return -1;
+ }
+
+ /* we need to update the data in the cache, in order to get the same data */
+ if (!last_stage) {
+ memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
+ }
+
+ /* Send XBZRLE based compressed page */
+ bytes_xbzrle = save_page_header(f, block, offset | RAM_SAVE_FLAG_XBZRLE);
+ qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
+ qemu_put_be16(f, encoded_len);
+ qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
+ bytes_xbzrle += encoded_len + 1 + 2;
+ acct_info.xbzrle_pages++;
+ acct_info.xbzrle_bytes += bytes_xbzrle;
+ *bytes_transferred += bytes_xbzrle;
+
+ return 1;
+}
+
+static inline
+ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
+ ram_addr_t start)
+{
+ unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
+ unsigned long nr = base + (start >> TARGET_PAGE_BITS);
+ uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
+ unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
+
+ unsigned long next;
+
+ if (ram_bulk_stage && nr > base) {
+ next = nr + 1;
+ } else {
+ next = find_next_bit(migration_bitmap, size, nr);
+ }
+
+ if (next < size) {
+ clear_bit(next, migration_bitmap);
+ migration_dirty_pages--;
+ }
+ return (next - base) << TARGET_PAGE_BITS;
+}
+
+static inline bool migration_bitmap_set_dirty(ram_addr_t addr)
+{
+ bool ret;
+ int nr = addr >> TARGET_PAGE_BITS;
+
+ ret = test_and_set_bit(nr, migration_bitmap);
+
+ if (!ret) {
+ migration_dirty_pages++;
+ }
+ return ret;
+}
+
+static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
+{
+ ram_addr_t addr;
+ unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
+
+ /* start address is aligned at the start of a word? */
+ if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {
+ int k;
+ int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
+ unsigned long *src = ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION];
+
+ for (k = page; k < page + nr; k++) {
+ if (src[k]) {
+ unsigned long new_dirty;
+ new_dirty = ~migration_bitmap[k];
+ migration_bitmap[k] |= src[k];
+ new_dirty &= src[k];
+ migration_dirty_pages += ctpopl(new_dirty);
+ src[k] = 0;
+ }
+ }
+ } else {
+ for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
+ if (cpu_physical_memory_get_dirty(start + addr,
+ TARGET_PAGE_SIZE,
+ DIRTY_MEMORY_MIGRATION)) {
+ cpu_physical_memory_reset_dirty(start + addr,
+ TARGET_PAGE_SIZE,
+ DIRTY_MEMORY_MIGRATION);
+ migration_bitmap_set_dirty(start + addr);
+ }
+ }
+ }
+}
+
+
+/* Fix me: there are too many global variables used in migration process. */
+static int64_t start_time;
+static int64_t bytes_xfer_prev;
+static int64_t num_dirty_pages_period;
+static uint64_t xbzrle_cache_miss_prev;
+static uint64_t iterations_prev;
+
+static void migration_bitmap_sync_init(void)
+{
+ start_time = 0;
+ bytes_xfer_prev = 0;
+ num_dirty_pages_period = 0;
+ xbzrle_cache_miss_prev = 0;
+ iterations_prev = 0;
+}
+
+/* Called with iothread lock held, to protect ram_list.dirty_memory[] */
+static void migration_bitmap_sync(void)
+{
+ RAMBlock *block;
+ uint64_t num_dirty_pages_init = migration_dirty_pages;
+ MigrationState *s = migrate_get_current();
+ int64_t end_time;
+ int64_t bytes_xfer_now;
+
+ bitmap_sync_count++;
+
+ if (!bytes_xfer_prev) {
+ bytes_xfer_prev = ram_bytes_transferred();
+ }
+
+ if (!start_time) {
+ start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ }
+
+ trace_migration_bitmap_sync_start();
+ address_space_sync_dirty_bitmap(&address_space_memory);
+
+ rcu_read_lock();
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
+ }
+ rcu_read_unlock();
+
+ trace_migration_bitmap_sync_end(migration_dirty_pages
+ - num_dirty_pages_init);
+ num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;
+ end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+
+ /* more than 1 second = 1000 millisecons */
+ if (end_time > start_time + 1000) {
+ if (migrate_auto_converge()) {
+ /* The following detection logic can be refined later. For now:
+ Check to see if the dirtied bytes is 50% more than the approx.
+ amount of bytes that just got transferred since the last time we
+ were in this routine. If that happens >N times (for now N==4)
+ we turn on the throttle down logic */
+ bytes_xfer_now = ram_bytes_transferred();
+ if (s->dirty_pages_rate &&
+ (num_dirty_pages_period * TARGET_PAGE_SIZE >
+ (bytes_xfer_now - bytes_xfer_prev)/2) &&
+ (dirty_rate_high_cnt++ > 4)) {
+ trace_migration_throttle();
+ mig_throttle_on = true;
+ dirty_rate_high_cnt = 0;
+ }
+ bytes_xfer_prev = bytes_xfer_now;
+ } else {
+ mig_throttle_on = false;
+ }
+ if (migrate_use_xbzrle()) {
+ if (iterations_prev != acct_info.iterations) {
+ acct_info.xbzrle_cache_miss_rate =
+ (double)(acct_info.xbzrle_cache_miss -
+ xbzrle_cache_miss_prev) /
+ (acct_info.iterations - iterations_prev);
+ }
+ iterations_prev = acct_info.iterations;
+ xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
+ }
+ s->dirty_pages_rate = num_dirty_pages_period * 1000
+ / (end_time - start_time);
+ s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
+ start_time = end_time;
+ num_dirty_pages_period = 0;
+ s->dirty_sync_count = bitmap_sync_count;
+ }
+}
+
+/**
+ * ram_save_page: Send the given page to the stream
+ *
+ * Returns: Number of pages written.
+ *
+ * @f: QEMUFile where to send the data
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
+ bool last_stage, uint64_t *bytes_transferred)
+{
+ int pages = -1;
+ uint64_t bytes_xmit;
+ ram_addr_t current_addr;
+ MemoryRegion *mr = block->mr;
+ uint8_t *p;
+ int ret;
+ bool send_async = true;
+
+ p = memory_region_get_ram_ptr(mr) + offset;
+
+ /* In doubt sent page as normal */
+ bytes_xmit = 0;
+ ret = ram_control_save_page(f, block->offset,
+ offset, TARGET_PAGE_SIZE, &bytes_xmit);
+ if (bytes_xmit) {
+ *bytes_transferred += bytes_xmit;
+ pages = 1;
+ }
+
+ XBZRLE_cache_lock();
+
+ current_addr = block->offset + offset;
+
+ if (block == last_sent_block) {
+ offset |= RAM_SAVE_FLAG_CONTINUE;
+ }
+ if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
+ if (ret != RAM_SAVE_CONTROL_DELAYED) {
+ if (bytes_xmit > 0) {
+ acct_info.norm_pages++;
+ } else if (bytes_xmit == 0) {
+ acct_info.dup_pages++;
+ }
+ }
+ } else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
+ acct_info.dup_pages++;
+ *bytes_transferred += save_page_header(f, block,
+ offset | RAM_SAVE_FLAG_COMPRESS);
+ qemu_put_byte(f, 0);
+ *bytes_transferred += 1;
+ pages = 1;
+ /* Must let xbzrle know, otherwise a previous (now 0'd) cached
+ * page would be stale
+ */
+ xbzrle_cache_zero_page(current_addr);
+ } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
+ pages = save_xbzrle_page(f, &p, current_addr, block,
+ offset, last_stage, bytes_transferred);
+ if (!last_stage) {
+ /* Can't send this cached data async, since the cache page
+ * might get updated before it gets to the wire
+ */
+ send_async = false;
+ }
+ }
+
+ /* XBZRLE overflow or normal page */
+ if (pages == -1) {
+ *bytes_transferred += save_page_header(f, block,
+ offset | RAM_SAVE_FLAG_PAGE);
+ if (send_async) {
+ qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
+ } else {
+ qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+ }
+ *bytes_transferred += TARGET_PAGE_SIZE;
+ pages = 1;
+ acct_info.norm_pages++;
+ }
+
+ XBZRLE_cache_unlock();
+
+ return pages;
+}
+
+/**
+ * ram_find_and_save_block: Finds a dirty page and sends it to f
+ *
+ * Called within an RCU critical section.
+ *
+ * Returns: The number of pages written
+ * 0 means no dirty pages
+ *
+ * @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
+ */
+
+static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
+ uint64_t *bytes_transferred)
+{
+ RAMBlock *block = last_seen_block;
+ ram_addr_t offset = last_offset;
+ bool complete_round = false;
+ int pages = 0;
+ MemoryRegion *mr;
+
+ if (!block)
+ block = QLIST_FIRST_RCU(&ram_list.blocks);
+
+ while (true) {
+ mr = block->mr;
+ offset = migration_bitmap_find_and_reset_dirty(mr, offset);
+ if (complete_round && block == last_seen_block &&
+ offset >= last_offset) {
+ break;
+ }
+ if (offset >= block->used_length) {
+ offset = 0;
+ block = QLIST_NEXT_RCU(block, next);
+ if (!block) {
+ block = QLIST_FIRST_RCU(&ram_list.blocks);
+ complete_round = true;
+ ram_bulk_stage = false;
+ }
+ } else {
+ pages = ram_save_page(f, block, offset, last_stage,
+ bytes_transferred);
+
+ /* if page is unmodified, continue to the next */
+ if (pages > 0) {
+ last_sent_block = block;
+ break;
+ }
+ }
+ }
+
+ last_seen_block = block;
+ last_offset = offset;
+
+ return pages;
+}
+
+static uint64_t bytes_transferred;
+
+void acct_update_position(QEMUFile *f, size_t size, bool zero)
+{
+ uint64_t pages = size / TARGET_PAGE_SIZE;
+ if (zero) {
+ acct_info.dup_pages += pages;
+ } else {
+ acct_info.norm_pages += pages;
+ bytes_transferred += size;
+ qemu_update_position(f, size);
+ }
+}
+
+static ram_addr_t ram_save_remaining(void)
+{
+ return migration_dirty_pages;
+}
+
+uint64_t ram_bytes_remaining(void)
+{
+ return ram_save_remaining() * TARGET_PAGE_SIZE;
+}
+
+uint64_t ram_bytes_transferred(void)
+{
+ return bytes_transferred;
+}
+
+uint64_t ram_bytes_total(void)
+{
+ RAMBlock *block;
+ uint64_t total = 0;
+
+ rcu_read_lock();
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
+ total += block->used_length;
+ rcu_read_unlock();
+ return total;
+}
+
+void free_xbzrle_decoded_buf(void)
+{
+ g_free(xbzrle_decoded_buf);
+ xbzrle_decoded_buf = NULL;
+}
+
+static void migration_end(void)
+{
+ if (migration_bitmap) {
+ memory_global_dirty_log_stop();
+ g_free(migration_bitmap);
+ migration_bitmap = NULL;
+ }
+
+ XBZRLE_cache_lock();
+ if (XBZRLE.cache) {
+ cache_fini(XBZRLE.cache);
+ g_free(XBZRLE.encoded_buf);
+ g_free(XBZRLE.current_buf);
+ XBZRLE.cache = NULL;
+ XBZRLE.encoded_buf = NULL;
+ XBZRLE.current_buf = NULL;
+ }
+ XBZRLE_cache_unlock();
+}
+
+static void ram_migration_cancel(void *opaque)
+{
+ migration_end();
+}
+
+static void reset_ram_globals(void)
+{
+ last_seen_block = NULL;
+ last_sent_block = NULL;
+ last_offset = 0;
+ last_version = ram_list.version;
+ ram_bulk_stage = true;
+}
+
+#define MAX_WAIT 50 /* ms, half buffered_file limit */
+
+
+/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
+ * long-running RCU critical section. When rcu-reclaims in the code
+ * start to become numerous it will be necessary to reduce the
+ * granularity of these critical sections.
+ */
+
+static int ram_save_setup(QEMUFile *f, void *opaque)
+{
+ RAMBlock *block;
+ int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
+
+ mig_throttle_on = false;
+ dirty_rate_high_cnt = 0;
+ bitmap_sync_count = 0;
+ migration_bitmap_sync_init();
+
+ if (migrate_use_xbzrle()) {
+ XBZRLE_cache_lock();
+ XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
+ TARGET_PAGE_SIZE,
+ TARGET_PAGE_SIZE);
+ if (!XBZRLE.cache) {
+ XBZRLE_cache_unlock();
+ error_report("Error creating cache");
+ return -1;
+ }
+ XBZRLE_cache_unlock();
+
+ /* We prefer not to abort if there is no memory */
+ XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
+ if (!XBZRLE.encoded_buf) {
+ error_report("Error allocating encoded_buf");
+ return -1;
+ }
+
+ XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
+ if (!XBZRLE.current_buf) {
+ error_report("Error allocating current_buf");
+ g_free(XBZRLE.encoded_buf);
+ XBZRLE.encoded_buf = NULL;
+ return -1;
+ }
+
+ acct_clear();
+ }
+
+ /* iothread lock needed for ram_list.dirty_memory[] */
+ qemu_mutex_lock_iothread();
+ qemu_mutex_lock_ramlist();
+ rcu_read_lock();
+ bytes_transferred = 0;
+ reset_ram_globals();
+
+ ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
+ migration_bitmap = bitmap_new(ram_bitmap_pages);
+ bitmap_set(migration_bitmap, 0, ram_bitmap_pages);
+
+ /*
+ * Count the total number of pages used by ram blocks not including any
+ * gaps due to alignment or unplugs.
+ */
+ migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
+
+ memory_global_dirty_log_start();
+ migration_bitmap_sync();
+ qemu_mutex_unlock_ramlist();
+ qemu_mutex_unlock_iothread();
+
+ qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ qemu_put_byte(f, strlen(block->idstr));
+ qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
+ qemu_put_be64(f, block->used_length);
+ }
+
+ rcu_read_unlock();
+
+ ram_control_before_iterate(f, RAM_CONTROL_SETUP);
+ ram_control_after_iterate(f, RAM_CONTROL_SETUP);
+
+ qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
+
+ return 0;
+}
+
+static int ram_save_iterate(QEMUFile *f, void *opaque)
+{
+ int ret;
+ int i;
+ int64_t t0;
+ int pages_sent = 0;
+
+ rcu_read_lock();
+ if (ram_list.version != last_version) {
+ reset_ram_globals();
+ }
+
+ /* Read version before ram_list.blocks */
+ smp_rmb();
+
+ ram_control_before_iterate(f, RAM_CONTROL_ROUND);
+
+ t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ i = 0;
+ while ((ret = qemu_file_rate_limit(f)) == 0) {
+ int pages;
+
+ pages = ram_find_and_save_block(f, false, &bytes_transferred);
+ /* no more pages to sent */
+ if (pages == 0) {
+ break;
+ }
+ pages_sent += pages;
+ acct_info.iterations++;
+ check_guest_throttling();
+ /* we want to check in the 1st loop, just in case it was the 1st time
+ and we had to sync the dirty bitmap.
+ qemu_get_clock_ns() is a bit expensive, so we only check each some
+ iterations
+ */
+ if ((i & 63) == 0) {
+ uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
+ if (t1 > MAX_WAIT) {
+ DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",
+ t1, i);
+ break;
+ }
+ }
+ i++;
+ }
+ rcu_read_unlock();
+
+ /*
+ * Must occur before EOS (or any QEMUFile operation)
+ * because of RDMA protocol.
+ */
+ ram_control_after_iterate(f, RAM_CONTROL_ROUND);
+
+ qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
+ bytes_transferred += 8;
+
+ ret = qemu_file_get_error(f);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return pages_sent;
+}
+
+/* Called with iothread lock */
+static int ram_save_complete(QEMUFile *f, void *opaque)
+{
+ rcu_read_lock();
+
+ migration_bitmap_sync();
+
+ ram_control_before_iterate(f, RAM_CONTROL_FINISH);
+
+ /* try transferring iterative blocks of memory */
+
+ /* flush all remaining blocks regardless of rate limiting */
+ while (true) {
+ int pages;
+
+ pages = ram_find_and_save_block(f, true, &bytes_transferred);
+ /* no more blocks to sent */
+ if (pages == 0) {
+ break;
+ }
+ }
+
+ ram_control_after_iterate(f, RAM_CONTROL_FINISH);
+ migration_end();
+
+ rcu_read_unlock();
+ qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
+
+ return 0;
+}
+
+static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+{
+ uint64_t remaining_size;
+
+ remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
+
+ if (remaining_size < max_size) {
+ qemu_mutex_lock_iothread();
+ rcu_read_lock();
+ migration_bitmap_sync();
+ rcu_read_unlock();
+ qemu_mutex_unlock_iothread();
+ remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
+ }
+ return remaining_size;
+}
+
+static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
+{
+ unsigned int xh_len;
+ int xh_flags;
+
+ if (!xbzrle_decoded_buf) {
+ xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
+ }
+
+ /* extract RLE header */
+ xh_flags = qemu_get_byte(f);
+ xh_len = qemu_get_be16(f);
+
+ if (xh_flags != ENCODING_FLAG_XBZRLE) {
+ error_report("Failed to load XBZRLE page - wrong compression!");
+ return -1;
+ }
+
+ if (xh_len > TARGET_PAGE_SIZE) {
+ error_report("Failed to load XBZRLE page - len overflow!");
+ return -1;
+ }
+ /* load data and decode */
+ qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
+
+ /* decode RLE */
+ if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
+ TARGET_PAGE_SIZE) == -1) {
+ error_report("Failed to load XBZRLE page - decode error!");
+ return -1;
+ }
+
+ return 0;
+}
+
+/* Must be called from within a rcu critical section.
+ * Returns a pointer from within the RCU-protected ram_list.
+ */
+static inline void *host_from_stream_offset(QEMUFile *f,
+ ram_addr_t offset,
+ int flags)
+{
+ static RAMBlock *block = NULL;
+ char id[256];
+ uint8_t len;
+
+ if (flags & RAM_SAVE_FLAG_CONTINUE) {
+ if (!block || block->max_length <= offset) {
+ error_report("Ack, bad migration stream!");
+ return NULL;
+ }
+
+ return memory_region_get_ram_ptr(block->mr) + offset;
+ }
+
+ len = qemu_get_byte(f);
+ qemu_get_buffer(f, (uint8_t *)id, len);
+ id[len] = 0;
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ if (!strncmp(id, block->idstr, sizeof(id)) &&
+ block->max_length > offset) {
+ return memory_region_get_ram_ptr(block->mr) + offset;
+ }
+ }
+
+ error_report("Can't find block %s!", id);
+ return NULL;
+}
+
+/*
+ * If a page (or a whole RDMA chunk) has been
+ * determined to be zero, then zap it.
+ */
+void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
+{
+ if (ch != 0 || !is_zero_range(host, size)) {
+ memset(host, ch, size);
+ }
+}
+
+static int ram_load(QEMUFile *f, void *opaque, int version_id)
+{
+ int flags = 0, ret = 0;
+ static uint64_t seq_iter;
+
+ seq_iter++;
+
+ if (version_id != 4) {
+ ret = -EINVAL;
+ }
+
+ /* This RCU critical section can be very long running.
+ * When RCU reclaims in the code start to become numerous,
+ * it will be necessary to reduce the granularity of this
+ * critical section.
+ */
+ rcu_read_lock();
+ while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
+ ram_addr_t addr, total_ram_bytes;
+ void *host;
+ uint8_t ch;
+
+ addr = qemu_get_be64(f);
+ flags = addr & ~TARGET_PAGE_MASK;
+ addr &= TARGET_PAGE_MASK;
+
+ switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
+ case RAM_SAVE_FLAG_MEM_SIZE:
+ /* Synchronize RAM block list */
+ total_ram_bytes = addr;
+ while (!ret && total_ram_bytes) {
+ RAMBlock *block;
+ uint8_t len;
+ char id[256];
+ ram_addr_t length;
+
+ len = qemu_get_byte(f);
+ qemu_get_buffer(f, (uint8_t *)id, len);
+ id[len] = 0;
+ length = qemu_get_be64(f);
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ if (!strncmp(id, block->idstr, sizeof(id))) {
+ if (length != block->used_length) {
+ Error *local_err = NULL;
+
+ ret = qemu_ram_resize(block->offset, length, &local_err);
+ if (local_err) {
+ error_report_err(local_err);
+ }
+ }
+ ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
+ block->idstr);
+ break;
+ }
+ }
+
+ if (!block) {
+ error_report("Unknown ramblock \"%s\", cannot "
+ "accept migration", id);
+ ret = -EINVAL;
+ }
+
+ total_ram_bytes -= length;
+ }
+ break;
+ case RAM_SAVE_FLAG_COMPRESS:
+ host = host_from_stream_offset(f, addr, flags);
+ if (!host) {
+ error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+ ret = -EINVAL;
+ break;
+ }
+ ch = qemu_get_byte(f);
+ ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
+ break;
+ case RAM_SAVE_FLAG_PAGE:
+ host = host_from_stream_offset(f, addr, flags);
+ if (!host) {
+ error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+ ret = -EINVAL;
+ break;
+ }
+ qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
+ break;
+ case RAM_SAVE_FLAG_XBZRLE:
+ host = host_from_stream_offset(f, addr, flags);
+ if (!host) {
+ error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+ ret = -EINVAL;
+ break;
+ }
+ if (load_xbzrle(f, addr, host) < 0) {
+ error_report("Failed to decompress XBZRLE page at "
+ RAM_ADDR_FMT, addr);
+ ret = -EINVAL;
+ break;
+ }
+ break;
+ case RAM_SAVE_FLAG_EOS:
+ /* normal exit */
+ break;
+ default:
+ if (flags & RAM_SAVE_FLAG_HOOK) {
+ ram_control_load_hook(f, RAM_CONTROL_HOOK, NULL);
+ } else {
+ error_report("Unknown combination of migration flags: %#x",
+ flags);
+ ret = -EINVAL;
+ }
+ }
+ if (!ret) {
+ ret = qemu_file_get_error(f);
+ }
+ }
+
+ rcu_read_unlock();
+ DPRINTF("Completed load of VM with exit code %d seq iteration "
+ "%" PRIu64 "\n", ret, seq_iter);
+ return ret;
+}
+
+static SaveVMHandlers savevm_ram_handlers = {
+ .save_live_setup = ram_save_setup,
+ .save_live_iterate = ram_save_iterate,
+ .save_live_complete = ram_save_complete,
+ .save_live_pending = ram_save_pending,
+ .load_state = ram_load,
+ .cancel = ram_migration_cancel,
+};
+
+void ram_mig_init(void)
+{
+ qemu_mutex_init(&XBZRLE.lock);
+ register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
+}
+
+/* Stub function that's gets run on the vcpu when its brought out of the
+ VM to run inside qemu via async_run_on_cpu()*/
+static void mig_sleep_cpu(void *opq)
+{
+ qemu_mutex_unlock_iothread();
+ g_usleep(30*1000);
+ qemu_mutex_lock_iothread();
+}
+
+/* To reduce the dirty rate explicitly disallow the VCPUs from spending
+ much time in the VM. The migration thread will try to catchup.
+ Workload will experience a performance drop.
+*/
+static void mig_throttle_guest_down(void)
+{
+ CPUState *cpu;
+
+ qemu_mutex_lock_iothread();
+ CPU_FOREACH(cpu) {
+ async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
+ }
+ qemu_mutex_unlock_iothread();
+}
+
+static void check_guest_throttling(void)
+{
+ static int64_t t0;
+ int64_t t1;
+
+ if (!mig_throttle_on) {
+ return;
+ }
+
+ if (!t0) {
+ t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ return;
+ }
+
+ t1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+
+ /* If it has been more than 40 ms since the last time the guest
+ * was throttled then do it again.
+ */
+ if (40 < (t1-t0)/1000000) {
+ mig_throttle_guest_down();
+ t0 = t1;
+ }
+}
diff --git a/trace-events b/trace-events
index 482dc01..450022d 100644
--- a/trace-events
+++ b/trace-events
@@ -1193,7 +1193,7 @@ vmstate_subsection_load_good(const char *parent) "%s"
# qemu-file.c
qemu_file_fclose(void) ""
-# arch_init.c
+# migration/ram.c
migration_bitmap_sync_start(void) ""
migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
migration_throttle(void) ""
--
1.8.3.1