The main RAM load loop has a call to host_from_stream_offset for each page type that actually loads data with the same test; factor it out before the switch. The host = NULL is to silence a bogus gcc warning of an unitialised in the RAM_SAVE_COMPRESS_PAGE case, it doesn't seem to realise that host is always initialised by the if at the top in the cases the switch takes. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
1714 lines
51 KiB
C
1714 lines
51 KiB
C
/*
|
|
* QEMU System Emulator
|
|
*
|
|
* Copyright (c) 2003-2008 Fabrice Bellard
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* Copyright (c) 2011-2015 Red Hat Inc
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*
|
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* Authors:
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* Juan Quintela <quintela@redhat.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdint.h>
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#include <zlib.h>
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#include "qemu/bitops.h"
|
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#include "qemu/bitmap.h"
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#include "qemu/timer.h"
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#include "qemu/main-loop.h"
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#include "migration/migration.h"
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#include "exec/address-spaces.h"
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#include "migration/page_cache.h"
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#include "qemu/error-report.h"
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#include "trace.h"
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#include "exec/ram_addr.h"
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#include "qemu/rcu_queue.h"
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|
|
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#ifdef DEBUG_MIGRATION_RAM
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#define DPRINTF(fmt, ...) \
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do { fprintf(stdout, "migration_ram: " fmt, ## __VA_ARGS__); } while (0)
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#else
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#define DPRINTF(fmt, ...) \
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do { } while (0)
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#endif
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|
|
|
static int dirty_rate_high_cnt;
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|
|
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static uint64_t bitmap_sync_count;
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|
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/***********************************************************/
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/* ram save/restore */
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#define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */
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#define RAM_SAVE_FLAG_COMPRESS 0x02
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#define RAM_SAVE_FLAG_MEM_SIZE 0x04
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#define RAM_SAVE_FLAG_PAGE 0x08
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#define RAM_SAVE_FLAG_EOS 0x10
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#define RAM_SAVE_FLAG_CONTINUE 0x20
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#define RAM_SAVE_FLAG_XBZRLE 0x40
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/* 0x80 is reserved in migration.h start with 0x100 next */
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#define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100
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|
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static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
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|
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static inline bool is_zero_range(uint8_t *p, uint64_t size)
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{
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return buffer_find_nonzero_offset(p, size) == size;
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}
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|
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/* struct contains XBZRLE cache and a static page
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used by the compression */
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static struct {
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/* buffer used for XBZRLE encoding */
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uint8_t *encoded_buf;
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/* buffer for storing page content */
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uint8_t *current_buf;
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/* Cache for XBZRLE, Protected by lock. */
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PageCache *cache;
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QemuMutex lock;
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} XBZRLE;
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/* buffer used for XBZRLE decoding */
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static uint8_t *xbzrle_decoded_buf;
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static void XBZRLE_cache_lock(void)
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{
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if (migrate_use_xbzrle())
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qemu_mutex_lock(&XBZRLE.lock);
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}
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static void XBZRLE_cache_unlock(void)
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{
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if (migrate_use_xbzrle())
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qemu_mutex_unlock(&XBZRLE.lock);
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}
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/*
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* called from qmp_migrate_set_cache_size in main thread, possibly while
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* a migration is in progress.
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* A running migration maybe using the cache and might finish during this
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* call, hence changes to the cache are protected by XBZRLE.lock().
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*/
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int64_t xbzrle_cache_resize(int64_t new_size)
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{
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PageCache *new_cache;
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int64_t ret;
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if (new_size < TARGET_PAGE_SIZE) {
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return -1;
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}
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XBZRLE_cache_lock();
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if (XBZRLE.cache != NULL) {
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if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
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goto out_new_size;
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}
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new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
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TARGET_PAGE_SIZE);
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if (!new_cache) {
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error_report("Error creating cache");
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ret = -1;
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goto out;
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}
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cache_fini(XBZRLE.cache);
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XBZRLE.cache = new_cache;
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}
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out_new_size:
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ret = pow2floor(new_size);
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out:
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XBZRLE_cache_unlock();
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return ret;
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}
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/* accounting for migration statistics */
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typedef struct AccountingInfo {
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uint64_t dup_pages;
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uint64_t skipped_pages;
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uint64_t norm_pages;
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uint64_t iterations;
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uint64_t xbzrle_bytes;
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uint64_t xbzrle_pages;
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uint64_t xbzrle_cache_miss;
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double xbzrle_cache_miss_rate;
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uint64_t xbzrle_overflows;
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} AccountingInfo;
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static AccountingInfo acct_info;
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static void acct_clear(void)
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{
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memset(&acct_info, 0, sizeof(acct_info));
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}
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uint64_t dup_mig_bytes_transferred(void)
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{
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return acct_info.dup_pages * TARGET_PAGE_SIZE;
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}
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uint64_t dup_mig_pages_transferred(void)
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{
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return acct_info.dup_pages;
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}
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uint64_t skipped_mig_bytes_transferred(void)
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{
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return acct_info.skipped_pages * TARGET_PAGE_SIZE;
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}
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uint64_t skipped_mig_pages_transferred(void)
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{
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return acct_info.skipped_pages;
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}
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uint64_t norm_mig_bytes_transferred(void)
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{
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return acct_info.norm_pages * TARGET_PAGE_SIZE;
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}
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uint64_t norm_mig_pages_transferred(void)
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{
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return acct_info.norm_pages;
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}
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uint64_t xbzrle_mig_bytes_transferred(void)
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{
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return acct_info.xbzrle_bytes;
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}
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uint64_t xbzrle_mig_pages_transferred(void)
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{
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return acct_info.xbzrle_pages;
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}
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uint64_t xbzrle_mig_pages_cache_miss(void)
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{
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return acct_info.xbzrle_cache_miss;
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}
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double xbzrle_mig_cache_miss_rate(void)
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{
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return acct_info.xbzrle_cache_miss_rate;
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}
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uint64_t xbzrle_mig_pages_overflow(void)
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{
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return acct_info.xbzrle_overflows;
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}
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/* This is the last block that we have visited serching for dirty pages
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*/
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static RAMBlock *last_seen_block;
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/* This is the last block from where we have sent data */
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static RAMBlock *last_sent_block;
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static ram_addr_t last_offset;
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static QemuMutex migration_bitmap_mutex;
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static uint64_t migration_dirty_pages;
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static uint32_t last_version;
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static bool ram_bulk_stage;
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/* used by the search for pages to send */
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struct PageSearchStatus {
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/* Current block being searched */
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RAMBlock *block;
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/* Current offset to search from */
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ram_addr_t offset;
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/* Set once we wrap around */
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bool complete_round;
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};
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typedef struct PageSearchStatus PageSearchStatus;
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static struct BitmapRcu {
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struct rcu_head rcu;
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unsigned long *bmap;
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} *migration_bitmap_rcu;
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struct CompressParam {
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bool start;
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bool done;
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QEMUFile *file;
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QemuMutex mutex;
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QemuCond cond;
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RAMBlock *block;
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ram_addr_t offset;
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};
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typedef struct CompressParam CompressParam;
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struct DecompressParam {
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bool start;
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QemuMutex mutex;
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QemuCond cond;
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void *des;
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uint8 *compbuf;
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int len;
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};
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typedef struct DecompressParam DecompressParam;
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static CompressParam *comp_param;
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static QemuThread *compress_threads;
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/* comp_done_cond is used to wake up the migration thread when
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* one of the compression threads has finished the compression.
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* comp_done_lock is used to co-work with comp_done_cond.
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*/
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static QemuMutex *comp_done_lock;
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static QemuCond *comp_done_cond;
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/* The empty QEMUFileOps will be used by file in CompressParam */
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static const QEMUFileOps empty_ops = { };
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static bool compression_switch;
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static bool quit_comp_thread;
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static bool quit_decomp_thread;
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static DecompressParam *decomp_param;
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static QemuThread *decompress_threads;
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static uint8_t *compressed_data_buf;
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static int do_compress_ram_page(CompressParam *param);
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static void *do_data_compress(void *opaque)
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{
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CompressParam *param = opaque;
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while (!quit_comp_thread) {
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qemu_mutex_lock(¶m->mutex);
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/* Re-check the quit_comp_thread in case of
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* terminate_compression_threads is called just before
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* qemu_mutex_lock(¶m->mutex) and after
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* while(!quit_comp_thread), re-check it here can make
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* sure the compression thread terminate as expected.
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*/
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while (!param->start && !quit_comp_thread) {
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qemu_cond_wait(¶m->cond, ¶m->mutex);
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}
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if (!quit_comp_thread) {
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do_compress_ram_page(param);
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}
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param->start = false;
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qemu_mutex_unlock(¶m->mutex);
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|
|
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qemu_mutex_lock(comp_done_lock);
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param->done = true;
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qemu_cond_signal(comp_done_cond);
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qemu_mutex_unlock(comp_done_lock);
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}
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return NULL;
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}
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|
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static inline void terminate_compression_threads(void)
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{
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int idx, thread_count;
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thread_count = migrate_compress_threads();
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quit_comp_thread = true;
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for (idx = 0; idx < thread_count; idx++) {
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qemu_mutex_lock(&comp_param[idx].mutex);
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qemu_cond_signal(&comp_param[idx].cond);
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qemu_mutex_unlock(&comp_param[idx].mutex);
|
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}
|
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}
|
|
|
|
void migrate_compress_threads_join(void)
|
|
{
|
|
int i, thread_count;
|
|
|
|
if (!migrate_use_compression()) {
|
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return;
|
|
}
|
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terminate_compression_threads();
|
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thread_count = migrate_compress_threads();
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|
for (i = 0; i < thread_count; i++) {
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qemu_thread_join(compress_threads + i);
|
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qemu_fclose(comp_param[i].file);
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qemu_mutex_destroy(&comp_param[i].mutex);
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qemu_cond_destroy(&comp_param[i].cond);
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}
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qemu_mutex_destroy(comp_done_lock);
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qemu_cond_destroy(comp_done_cond);
|
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g_free(compress_threads);
|
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g_free(comp_param);
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|
g_free(comp_done_cond);
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g_free(comp_done_lock);
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compress_threads = NULL;
|
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comp_param = NULL;
|
|
comp_done_cond = NULL;
|
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comp_done_lock = NULL;
|
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}
|
|
|
|
void migrate_compress_threads_create(void)
|
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{
|
|
int i, thread_count;
|
|
|
|
if (!migrate_use_compression()) {
|
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return;
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}
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quit_comp_thread = false;
|
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compression_switch = true;
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thread_count = migrate_compress_threads();
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compress_threads = g_new0(QemuThread, thread_count);
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comp_param = g_new0(CompressParam, thread_count);
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comp_done_cond = g_new0(QemuCond, 1);
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comp_done_lock = g_new0(QemuMutex, 1);
|
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qemu_cond_init(comp_done_cond);
|
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qemu_mutex_init(comp_done_lock);
|
|
for (i = 0; i < thread_count; i++) {
|
|
/* com_param[i].file is just used as a dummy buffer to save data, set
|
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* it's ops to empty.
|
|
*/
|
|
comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
|
|
comp_param[i].done = true;
|
|
qemu_mutex_init(&comp_param[i].mutex);
|
|
qemu_cond_init(&comp_param[i].cond);
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qemu_thread_create(compress_threads + i, "compress",
|
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do_data_compress, comp_param + i,
|
|
QEMU_THREAD_JOINABLE);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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, len;
|
|
|
|
qemu_put_be64(f, offset);
|
|
size = 8;
|
|
|
|
if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
|
|
len = strlen(block->idstr);
|
|
qemu_put_byte(f, len);
|
|
qemu_put_buffer(f, (uint8_t *)block->idstr, len);
|
|
size += 1 + len;
|
|
}
|
|
return size;
|
|
}
|
|
|
|
/* Reduce amount of guest cpu execution to hopefully slow down memory writes.
|
|
* If guest dirty memory rate is reduced below the rate at which we can
|
|
* transfer pages to the destination then we should be able to complete
|
|
* migration. Some workloads dirty memory way too fast and will not effectively
|
|
* converge, even with auto-converge.
|
|
*/
|
|
static void mig_throttle_guest_down(void)
|
|
{
|
|
MigrationState *s = migrate_get_current();
|
|
uint64_t pct_initial =
|
|
s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL];
|
|
uint64_t pct_icrement =
|
|
s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT];
|
|
|
|
/* We have not started throttling yet. Let's start it. */
|
|
if (!cpu_throttle_active()) {
|
|
cpu_throttle_set(pct_initial);
|
|
} else {
|
|
/* Throttling already on, just increase the rate */
|
|
cpu_throttle_set(cpu_throttle_get_percentage() + pct_icrement);
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/* Called with rcu_read_lock() to protect migration_bitmap */
|
|
static inline
|
|
ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb,
|
|
ram_addr_t start)
|
|
{
|
|
unsigned long base = rb->offset >> TARGET_PAGE_BITS;
|
|
unsigned long nr = base + (start >> TARGET_PAGE_BITS);
|
|
uint64_t rb_size = rb->used_length;
|
|
unsigned long size = base + (rb_size >> TARGET_PAGE_BITS);
|
|
unsigned long *bitmap;
|
|
|
|
unsigned long next;
|
|
|
|
bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
|
|
if (ram_bulk_stage && nr > base) {
|
|
next = nr + 1;
|
|
} else {
|
|
next = find_next_bit(bitmap, size, nr);
|
|
}
|
|
|
|
if (next < size) {
|
|
clear_bit(next, bitmap);
|
|
migration_dirty_pages--;
|
|
}
|
|
return (next - base) << TARGET_PAGE_BITS;
|
|
}
|
|
|
|
/* Called with rcu_read_lock() to protect migration_bitmap */
|
|
static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
|
|
{
|
|
unsigned long *bitmap;
|
|
bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
|
|
migration_dirty_pages +=
|
|
cpu_physical_memory_sync_dirty_bitmap(bitmap, start, length);
|
|
}
|
|
|
|
/* 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);
|
|
|
|
qemu_mutex_lock(&migration_bitmap_mutex);
|
|
rcu_read_lock();
|
|
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
|
|
migration_bitmap_sync_range(block->offset, block->used_length);
|
|
}
|
|
rcu_read_unlock();
|
|
qemu_mutex_unlock(&migration_bitmap_mutex);
|
|
|
|
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 twice, start or increase
|
|
throttling */
|
|
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++ >= 2)) {
|
|
trace_migration_throttle();
|
|
dirty_rate_high_cnt = 0;
|
|
mig_throttle_guest_down();
|
|
}
|
|
bytes_xfer_prev = bytes_xfer_now;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* save_zero_page: Send the zero 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
|
|
* @p: pointer to the page
|
|
* @bytes_transferred: increase it with the number of transferred bytes
|
|
*/
|
|
static int save_zero_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
|
|
uint8_t *p, uint64_t *bytes_transferred)
|
|
{
|
|
int pages = -1;
|
|
|
|
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;
|
|
}
|
|
|
|
return pages;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
uint8_t *p;
|
|
int ret;
|
|
bool send_async = true;
|
|
|
|
p = block->host + 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 {
|
|
pages = save_zero_page(f, block, offset, p, bytes_transferred);
|
|
if (pages > 0) {
|
|
/* 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;
|
|
}
|
|
|
|
static int do_compress_ram_page(CompressParam *param)
|
|
{
|
|
int bytes_sent, blen;
|
|
uint8_t *p;
|
|
RAMBlock *block = param->block;
|
|
ram_addr_t offset = param->offset;
|
|
|
|
p = block->host + (offset & TARGET_PAGE_MASK);
|
|
|
|
bytes_sent = save_page_header(param->file, block, offset |
|
|
RAM_SAVE_FLAG_COMPRESS_PAGE);
|
|
blen = qemu_put_compression_data(param->file, p, TARGET_PAGE_SIZE,
|
|
migrate_compress_level());
|
|
bytes_sent += blen;
|
|
|
|
return bytes_sent;
|
|
}
|
|
|
|
static inline void start_compression(CompressParam *param)
|
|
{
|
|
param->done = false;
|
|
qemu_mutex_lock(¶m->mutex);
|
|
param->start = true;
|
|
qemu_cond_signal(¶m->cond);
|
|
qemu_mutex_unlock(¶m->mutex);
|
|
}
|
|
|
|
static inline void start_decompression(DecompressParam *param)
|
|
{
|
|
qemu_mutex_lock(¶m->mutex);
|
|
param->start = true;
|
|
qemu_cond_signal(¶m->cond);
|
|
qemu_mutex_unlock(¶m->mutex);
|
|
}
|
|
|
|
static uint64_t bytes_transferred;
|
|
|
|
static void flush_compressed_data(QEMUFile *f)
|
|
{
|
|
int idx, len, thread_count;
|
|
|
|
if (!migrate_use_compression()) {
|
|
return;
|
|
}
|
|
thread_count = migrate_compress_threads();
|
|
for (idx = 0; idx < thread_count; idx++) {
|
|
if (!comp_param[idx].done) {
|
|
qemu_mutex_lock(comp_done_lock);
|
|
while (!comp_param[idx].done && !quit_comp_thread) {
|
|
qemu_cond_wait(comp_done_cond, comp_done_lock);
|
|
}
|
|
qemu_mutex_unlock(comp_done_lock);
|
|
}
|
|
if (!quit_comp_thread) {
|
|
len = qemu_put_qemu_file(f, comp_param[idx].file);
|
|
bytes_transferred += len;
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void set_compress_params(CompressParam *param, RAMBlock *block,
|
|
ram_addr_t offset)
|
|
{
|
|
param->block = block;
|
|
param->offset = offset;
|
|
}
|
|
|
|
static int compress_page_with_multi_thread(QEMUFile *f, RAMBlock *block,
|
|
ram_addr_t offset,
|
|
uint64_t *bytes_transferred)
|
|
{
|
|
int idx, thread_count, bytes_xmit = -1, pages = -1;
|
|
|
|
thread_count = migrate_compress_threads();
|
|
qemu_mutex_lock(comp_done_lock);
|
|
while (true) {
|
|
for (idx = 0; idx < thread_count; idx++) {
|
|
if (comp_param[idx].done) {
|
|
bytes_xmit = qemu_put_qemu_file(f, comp_param[idx].file);
|
|
set_compress_params(&comp_param[idx], block, offset);
|
|
start_compression(&comp_param[idx]);
|
|
pages = 1;
|
|
acct_info.norm_pages++;
|
|
*bytes_transferred += bytes_xmit;
|
|
break;
|
|
}
|
|
}
|
|
if (pages > 0) {
|
|
break;
|
|
} else {
|
|
qemu_cond_wait(comp_done_cond, comp_done_lock);
|
|
}
|
|
}
|
|
qemu_mutex_unlock(comp_done_lock);
|
|
|
|
return pages;
|
|
}
|
|
|
|
/**
|
|
* ram_save_compressed_page: compress the given page and send it 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_compressed_page(QEMUFile *f, RAMBlock *block,
|
|
ram_addr_t offset, bool last_stage,
|
|
uint64_t *bytes_transferred)
|
|
{
|
|
int pages = -1;
|
|
uint64_t bytes_xmit;
|
|
uint8_t *p;
|
|
int ret;
|
|
|
|
p = block->host + offset;
|
|
|
|
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;
|
|
}
|
|
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 {
|
|
/* When starting the process of a new block, the first page of
|
|
* the block should be sent out before other pages in the same
|
|
* block, and all the pages in last block should have been sent
|
|
* out, keeping this order is important, because the 'cont' flag
|
|
* is used to avoid resending the block name.
|
|
*/
|
|
if (block != last_sent_block) {
|
|
flush_compressed_data(f);
|
|
pages = save_zero_page(f, block, offset, p, bytes_transferred);
|
|
if (pages == -1) {
|
|
set_compress_params(&comp_param[0], block, offset);
|
|
/* Use the qemu thread to compress the data to make sure the
|
|
* first page is sent out before other pages
|
|
*/
|
|
bytes_xmit = do_compress_ram_page(&comp_param[0]);
|
|
acct_info.norm_pages++;
|
|
qemu_put_qemu_file(f, comp_param[0].file);
|
|
*bytes_transferred += bytes_xmit;
|
|
pages = 1;
|
|
}
|
|
} else {
|
|
pages = save_zero_page(f, block, offset, p, bytes_transferred);
|
|
if (pages == -1) {
|
|
pages = compress_page_with_multi_thread(f, block, offset,
|
|
bytes_transferred);
|
|
}
|
|
}
|
|
}
|
|
|
|
return pages;
|
|
}
|
|
|
|
/*
|
|
* Find the next dirty page and update any state associated with
|
|
* the search process.
|
|
*
|
|
* Returns: True if a page is found
|
|
*
|
|
* @f: Current migration stream.
|
|
* @pss: Data about the state of the current dirty page scan.
|
|
* @*again: Set to false if the search has scanned the whole of RAM
|
|
*/
|
|
static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
|
|
bool *again)
|
|
{
|
|
pss->offset = migration_bitmap_find_and_reset_dirty(pss->block,
|
|
pss->offset);
|
|
if (pss->complete_round && pss->block == last_seen_block &&
|
|
pss->offset >= last_offset) {
|
|
/*
|
|
* We've been once around the RAM and haven't found anything.
|
|
* Give up.
|
|
*/
|
|
*again = false;
|
|
return false;
|
|
}
|
|
if (pss->offset >= pss->block->used_length) {
|
|
/* Didn't find anything in this RAM Block */
|
|
pss->offset = 0;
|
|
pss->block = QLIST_NEXT_RCU(pss->block, next);
|
|
if (!pss->block) {
|
|
/* Hit the end of the list */
|
|
pss->block = QLIST_FIRST_RCU(&ram_list.blocks);
|
|
/* Flag that we've looped */
|
|
pss->complete_round = true;
|
|
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.
|
|
*/
|
|
flush_compressed_data(f);
|
|
compression_switch = false;
|
|
}
|
|
}
|
|
/* Didn't find anything this time, but try again on the new block */
|
|
*again = true;
|
|
return false;
|
|
} else {
|
|
/* Can go around again, but... */
|
|
*again = true;
|
|
/* We've found something so probably don't need to */
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
PageSearchStatus pss;
|
|
int pages = 0;
|
|
bool again, found;
|
|
|
|
pss.block = last_seen_block;
|
|
pss.offset = last_offset;
|
|
pss.complete_round = false;
|
|
|
|
if (!pss.block) {
|
|
pss.block = QLIST_FIRST_RCU(&ram_list.blocks);
|
|
}
|
|
|
|
do {
|
|
found = find_dirty_block(f, &pss, &again);
|
|
|
|
if (found) {
|
|
if (compression_switch && migrate_use_compression()) {
|
|
pages = ram_save_compressed_page(f, pss.block, pss.offset,
|
|
last_stage,
|
|
bytes_transferred);
|
|
} else {
|
|
pages = ram_save_page(f, pss.block, pss.offset, last_stage,
|
|
bytes_transferred);
|
|
}
|
|
|
|
/* if page is unmodified, continue to the next */
|
|
if (pages > 0) {
|
|
last_sent_block = pss.block;
|
|
}
|
|
}
|
|
} while (!pages && again);
|
|
|
|
last_seen_block = pss.block;
|
|
last_offset = pss.offset;
|
|
|
|
return pages;
|
|
}
|
|
|
|
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_bitmap_free(struct BitmapRcu *bmap)
|
|
{
|
|
g_free(bmap->bmap);
|
|
g_free(bmap);
|
|
}
|
|
|
|
static void ram_migration_cleanup(void *opaque)
|
|
{
|
|
/* caller have hold iothread lock or is in a bh, so there is
|
|
* no writing race against this migration_bitmap
|
|
*/
|
|
struct BitmapRcu *bitmap = migration_bitmap_rcu;
|
|
atomic_rcu_set(&migration_bitmap_rcu, NULL);
|
|
if (bitmap) {
|
|
memory_global_dirty_log_stop();
|
|
call_rcu(bitmap, migration_bitmap_free, rcu);
|
|
}
|
|
|
|
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 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 */
|
|
|
|
void migration_bitmap_extend(ram_addr_t old, ram_addr_t new)
|
|
{
|
|
/* called in qemu main thread, so there is
|
|
* no writing race against this migration_bitmap
|
|
*/
|
|
if (migration_bitmap_rcu) {
|
|
struct BitmapRcu *old_bitmap = migration_bitmap_rcu, *bitmap;
|
|
bitmap = g_new(struct BitmapRcu, 1);
|
|
bitmap->bmap = bitmap_new(new);
|
|
|
|
/* prevent migration_bitmap content from being set bit
|
|
* by migration_bitmap_sync_range() at the same time.
|
|
* it is safe to migration if migration_bitmap is cleared bit
|
|
* at the same time.
|
|
*/
|
|
qemu_mutex_lock(&migration_bitmap_mutex);
|
|
bitmap_copy(bitmap->bmap, old_bitmap->bmap, old);
|
|
bitmap_set(bitmap->bmap, old, new - old);
|
|
atomic_rcu_set(&migration_bitmap_rcu, bitmap);
|
|
qemu_mutex_unlock(&migration_bitmap_mutex);
|
|
migration_dirty_pages += new - old;
|
|
call_rcu(old_bitmap, migration_bitmap_free, rcu);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 'expected' is the value you expect the bitmap mostly to be full
|
|
* of; it won't bother printing lines that are all this value.
|
|
* If 'todump' is null the migration bitmap is dumped.
|
|
*/
|
|
void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
|
|
{
|
|
int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
|
|
|
|
int64_t cur;
|
|
int64_t linelen = 128;
|
|
char linebuf[129];
|
|
|
|
if (!todump) {
|
|
todump = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
|
|
}
|
|
|
|
for (cur = 0; cur < ram_pages; cur += linelen) {
|
|
int64_t curb;
|
|
bool found = false;
|
|
/*
|
|
* Last line; catch the case where the line length
|
|
* is longer than remaining ram
|
|
*/
|
|
if (cur + linelen > ram_pages) {
|
|
linelen = ram_pages - cur;
|
|
}
|
|
for (curb = 0; curb < linelen; curb++) {
|
|
bool thisbit = test_bit(cur + curb, todump);
|
|
linebuf[curb] = thisbit ? '1' : '.';
|
|
found = found || (thisbit != expected);
|
|
}
|
|
if (found) {
|
|
linebuf[curb] = '\0';
|
|
fprintf(stderr, "0x%08" PRIx64 " : %s\n", cur, linebuf);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* 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 */
|
|
|
|
dirty_rate_high_cnt = 0;
|
|
bitmap_sync_count = 0;
|
|
migration_bitmap_sync_init();
|
|
qemu_mutex_init(&migration_bitmap_mutex);
|
|
|
|
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_rcu = g_new(struct BitmapRcu, 1);
|
|
migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages);
|
|
bitmap_set(migration_bitmap_rcu->bmap, 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++;
|
|
|
|
/* 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++;
|
|
}
|
|
flush_compressed_data(f);
|
|
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;
|
|
}
|
|
}
|
|
|
|
flush_compressed_data(f);
|
|
ram_control_after_iterate(f, RAM_CONTROL_FINISH);
|
|
|
|
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 block->host + offset;
|
|
}
|
|
|
|
len = qemu_get_byte(f);
|
|
qemu_get_buffer(f, (uint8_t *)id, len);
|
|
id[len] = 0;
|
|
|
|
block = qemu_ram_block_by_name(id);
|
|
if (block && block->max_length > offset) {
|
|
return block->host + 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 void *do_data_decompress(void *opaque)
|
|
{
|
|
DecompressParam *param = opaque;
|
|
unsigned long pagesize;
|
|
|
|
while (!quit_decomp_thread) {
|
|
qemu_mutex_lock(¶m->mutex);
|
|
while (!param->start && !quit_decomp_thread) {
|
|
qemu_cond_wait(¶m->cond, ¶m->mutex);
|
|
pagesize = TARGET_PAGE_SIZE;
|
|
if (!quit_decomp_thread) {
|
|
/* uncompress() will return failed in some case, especially
|
|
* when the page is dirted when doing the compression, it's
|
|
* not a problem because the dirty page will be retransferred
|
|
* and uncompress() won't break the data in other pages.
|
|
*/
|
|
uncompress((Bytef *)param->des, &pagesize,
|
|
(const Bytef *)param->compbuf, param->len);
|
|
}
|
|
param->start = false;
|
|
}
|
|
qemu_mutex_unlock(¶m->mutex);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void migrate_decompress_threads_create(void)
|
|
{
|
|
int i, thread_count;
|
|
|
|
thread_count = migrate_decompress_threads();
|
|
decompress_threads = g_new0(QemuThread, thread_count);
|
|
decomp_param = g_new0(DecompressParam, thread_count);
|
|
compressed_data_buf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
|
|
quit_decomp_thread = false;
|
|
for (i = 0; i < thread_count; i++) {
|
|
qemu_mutex_init(&decomp_param[i].mutex);
|
|
qemu_cond_init(&decomp_param[i].cond);
|
|
decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
|
|
qemu_thread_create(decompress_threads + i, "decompress",
|
|
do_data_decompress, decomp_param + i,
|
|
QEMU_THREAD_JOINABLE);
|
|
}
|
|
}
|
|
|
|
void migrate_decompress_threads_join(void)
|
|
{
|
|
int i, thread_count;
|
|
|
|
quit_decomp_thread = true;
|
|
thread_count = migrate_decompress_threads();
|
|
for (i = 0; i < thread_count; i++) {
|
|
qemu_mutex_lock(&decomp_param[i].mutex);
|
|
qemu_cond_signal(&decomp_param[i].cond);
|
|
qemu_mutex_unlock(&decomp_param[i].mutex);
|
|
}
|
|
for (i = 0; i < thread_count; i++) {
|
|
qemu_thread_join(decompress_threads + i);
|
|
qemu_mutex_destroy(&decomp_param[i].mutex);
|
|
qemu_cond_destroy(&decomp_param[i].cond);
|
|
g_free(decomp_param[i].compbuf);
|
|
}
|
|
g_free(decompress_threads);
|
|
g_free(decomp_param);
|
|
g_free(compressed_data_buf);
|
|
decompress_threads = NULL;
|
|
decomp_param = NULL;
|
|
compressed_data_buf = NULL;
|
|
}
|
|
|
|
static void decompress_data_with_multi_threads(uint8_t *compbuf,
|
|
void *host, int len)
|
|
{
|
|
int idx, thread_count;
|
|
|
|
thread_count = migrate_decompress_threads();
|
|
while (true) {
|
|
for (idx = 0; idx < thread_count; idx++) {
|
|
if (!decomp_param[idx].start) {
|
|
memcpy(decomp_param[idx].compbuf, compbuf, len);
|
|
decomp_param[idx].des = host;
|
|
decomp_param[idx].len = len;
|
|
start_decompression(&decomp_param[idx]);
|
|
break;
|
|
}
|
|
}
|
|
if (idx < thread_count) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int ram_load(QEMUFile *f, void *opaque, int version_id)
|
|
{
|
|
int flags = 0, ret = 0;
|
|
static uint64_t seq_iter;
|
|
int len = 0;
|
|
|
|
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 = NULL;
|
|
uint8_t ch;
|
|
|
|
addr = qemu_get_be64(f);
|
|
flags = addr & ~TARGET_PAGE_MASK;
|
|
addr &= TARGET_PAGE_MASK;
|
|
|
|
if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
|
|
RAM_SAVE_FLAG_COMPRESS_PAGE | 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;
|
|
}
|
|
}
|
|
|
|
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;
|
|
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);
|
|
|
|
block = qemu_ram_block_by_name(id);
|
|
if (block) {
|
|
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);
|
|
} else {
|
|
error_report("Unknown ramblock \"%s\", cannot "
|
|
"accept migration", id);
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
total_ram_bytes -= length;
|
|
}
|
|
break;
|
|
|
|
case RAM_SAVE_FLAG_COMPRESS:
|
|
ch = qemu_get_byte(f);
|
|
ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
|
|
break;
|
|
|
|
case RAM_SAVE_FLAG_PAGE:
|
|
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
|
|
break;
|
|
|
|
case RAM_SAVE_FLAG_COMPRESS_PAGE:
|
|
len = qemu_get_be32(f);
|
|
if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
|
|
error_report("Invalid compressed data length: %d", len);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
qemu_get_buffer(f, compressed_data_buf, len);
|
|
decompress_data_with_multi_threads(compressed_data_buf, host, len);
|
|
break;
|
|
|
|
case RAM_SAVE_FLAG_XBZRLE:
|
|
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,
|
|
.cleanup = ram_migration_cleanup,
|
|
};
|
|
|
|
void ram_mig_init(void)
|
|
{
|
|
qemu_mutex_init(&XBZRLE.lock);
|
|
register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
|
|
}
|