Noticed while reviewing the file for newer patches.
Fixes: b35ebdf076
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200727203206.134996-1-eblake@redhat.com>
935 lines
27 KiB
C
935 lines
27 KiB
C
/*
|
|
* Block dirty bitmap postcopy migration
|
|
*
|
|
* Copyright IBM, Corp. 2009
|
|
* Copyright (c) 2016-2017 Virtuozzo International GmbH. All rights reserved.
|
|
*
|
|
* Authors:
|
|
* Liran Schour <lirans@il.ibm.com>
|
|
* Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2. See
|
|
* the COPYING file in the top-level directory.
|
|
* This file is derived from migration/block.c, so it's author and IBM copyright
|
|
* are here, although content is quite different.
|
|
*
|
|
* Contributions after 2012-01-13 are licensed under the terms of the
|
|
* GNU GPL, version 2 or (at your option) any later version.
|
|
*
|
|
* ***
|
|
*
|
|
* Here postcopy migration of dirty bitmaps is realized. Only QMP-addressable
|
|
* bitmaps are migrated.
|
|
*
|
|
* Bitmap migration implies creating bitmap with the same name and granularity
|
|
* in destination QEMU. If the bitmap with the same name (for the same node)
|
|
* already exists on destination an error will be generated.
|
|
*
|
|
* format of migration:
|
|
*
|
|
* # Header (shared for different chunk types)
|
|
* 1, 2 or 4 bytes: flags (see qemu_{put,put}_flags)
|
|
* [ 1 byte: node name size ] \ flags & DEVICE_NAME
|
|
* [ n bytes: node name ] /
|
|
* [ 1 byte: bitmap name size ] \ flags & BITMAP_NAME
|
|
* [ n bytes: bitmap name ] /
|
|
*
|
|
* # Start of bitmap migration (flags & START)
|
|
* header
|
|
* be64: granularity
|
|
* 1 byte: bitmap flags (corresponds to BdrvDirtyBitmap)
|
|
* bit 0 - bitmap is enabled
|
|
* bit 1 - bitmap is persistent
|
|
* bit 2 - bitmap is autoloading
|
|
* bits 3-7 - reserved, must be zero
|
|
*
|
|
* # Complete of bitmap migration (flags & COMPLETE)
|
|
* header
|
|
*
|
|
* # Data chunk of bitmap migration
|
|
* header
|
|
* be64: start sector
|
|
* be32: number of sectors
|
|
* [ be64: buffer size ] \ ! (flags & ZEROES)
|
|
* [ n bytes: buffer ] /
|
|
*
|
|
* The last chunk in stream should contain flags & EOS. The chunk may skip
|
|
* device and/or bitmap names, assuming them to be the same with the previous
|
|
* chunk.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "block/block.h"
|
|
#include "block/block_int.h"
|
|
#include "sysemu/block-backend.h"
|
|
#include "sysemu/runstate.h"
|
|
#include "qemu/main-loop.h"
|
|
#include "qemu/error-report.h"
|
|
#include "migration/misc.h"
|
|
#include "migration/migration.h"
|
|
#include "qemu-file.h"
|
|
#include "migration/vmstate.h"
|
|
#include "migration/register.h"
|
|
#include "qemu/hbitmap.h"
|
|
#include "qemu/cutils.h"
|
|
#include "qapi/error.h"
|
|
#include "trace.h"
|
|
|
|
#define CHUNK_SIZE (1 << 10)
|
|
|
|
/* Flags occupy one, two or four bytes (Big Endian). The size is determined as
|
|
* follows:
|
|
* in first (most significant) byte bit 8 is clear --> one byte
|
|
* in first byte bit 8 is set --> two or four bytes, depending on second
|
|
* byte:
|
|
* | in second byte bit 8 is clear --> two bytes
|
|
* | in second byte bit 8 is set --> four bytes
|
|
*/
|
|
#define DIRTY_BITMAP_MIG_FLAG_EOS 0x01
|
|
#define DIRTY_BITMAP_MIG_FLAG_ZEROES 0x02
|
|
#define DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME 0x04
|
|
#define DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME 0x08
|
|
#define DIRTY_BITMAP_MIG_FLAG_START 0x10
|
|
#define DIRTY_BITMAP_MIG_FLAG_COMPLETE 0x20
|
|
#define DIRTY_BITMAP_MIG_FLAG_BITS 0x40
|
|
|
|
#define DIRTY_BITMAP_MIG_EXTRA_FLAGS 0x80
|
|
|
|
#define DIRTY_BITMAP_MIG_START_FLAG_ENABLED 0x01
|
|
#define DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT 0x02
|
|
/* 0x04 was "AUTOLOAD" flags on older versions, now it is ignored */
|
|
#define DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK 0xf8
|
|
|
|
/* State of one bitmap during save process */
|
|
typedef struct SaveBitmapState {
|
|
/* Written during setup phase. */
|
|
BlockDriverState *bs;
|
|
const char *node_name;
|
|
BdrvDirtyBitmap *bitmap;
|
|
uint64_t total_sectors;
|
|
uint64_t sectors_per_chunk;
|
|
QSIMPLEQ_ENTRY(SaveBitmapState) entry;
|
|
uint8_t flags;
|
|
|
|
/* For bulk phase. */
|
|
bool bulk_completed;
|
|
uint64_t cur_sector;
|
|
} SaveBitmapState;
|
|
|
|
/* State of the dirty bitmap migration (DBM) during save process */
|
|
typedef struct DBMSaveState {
|
|
QSIMPLEQ_HEAD(, SaveBitmapState) dbms_list;
|
|
|
|
bool bulk_completed;
|
|
bool no_bitmaps;
|
|
|
|
/* for send_bitmap_bits() */
|
|
BlockDriverState *prev_bs;
|
|
BdrvDirtyBitmap *prev_bitmap;
|
|
} DBMSaveState;
|
|
|
|
typedef struct LoadBitmapState {
|
|
BlockDriverState *bs;
|
|
BdrvDirtyBitmap *bitmap;
|
|
bool migrated;
|
|
bool enabled;
|
|
} LoadBitmapState;
|
|
|
|
/* State of the dirty bitmap migration (DBM) during load process */
|
|
typedef struct DBMLoadState {
|
|
uint32_t flags;
|
|
char node_name[256];
|
|
char bitmap_name[256];
|
|
BlockDriverState *bs;
|
|
BdrvDirtyBitmap *bitmap;
|
|
|
|
bool before_vm_start_handled; /* set in dirty_bitmap_mig_before_vm_start */
|
|
|
|
/*
|
|
* cancelled
|
|
* Incoming migration is cancelled for some reason. That means that we
|
|
* still should read our chunks from migration stream, to not affect other
|
|
* migration objects (like RAM), but just ignore them and do not touch any
|
|
* bitmaps or nodes.
|
|
*/
|
|
bool cancelled;
|
|
|
|
GSList *bitmaps;
|
|
QemuMutex lock; /* protect bitmaps */
|
|
} DBMLoadState;
|
|
|
|
typedef struct DBMState {
|
|
DBMSaveState save;
|
|
DBMLoadState load;
|
|
} DBMState;
|
|
|
|
static DBMState dbm_state;
|
|
|
|
static uint32_t qemu_get_bitmap_flags(QEMUFile *f)
|
|
{
|
|
uint8_t flags = qemu_get_byte(f);
|
|
if (flags & DIRTY_BITMAP_MIG_EXTRA_FLAGS) {
|
|
flags = flags << 8 | qemu_get_byte(f);
|
|
if (flags & DIRTY_BITMAP_MIG_EXTRA_FLAGS) {
|
|
flags = flags << 16 | qemu_get_be16(f);
|
|
}
|
|
}
|
|
|
|
return flags;
|
|
}
|
|
|
|
static void qemu_put_bitmap_flags(QEMUFile *f, uint32_t flags)
|
|
{
|
|
/* The code currently does not send flags as more than one byte */
|
|
assert(!(flags & (0xffffff00 | DIRTY_BITMAP_MIG_EXTRA_FLAGS)));
|
|
|
|
qemu_put_byte(f, flags);
|
|
}
|
|
|
|
static void send_bitmap_header(QEMUFile *f, DBMSaveState *s,
|
|
SaveBitmapState *dbms, uint32_t additional_flags)
|
|
{
|
|
BlockDriverState *bs = dbms->bs;
|
|
BdrvDirtyBitmap *bitmap = dbms->bitmap;
|
|
uint32_t flags = additional_flags;
|
|
trace_send_bitmap_header_enter();
|
|
|
|
if (bs != s->prev_bs) {
|
|
s->prev_bs = bs;
|
|
flags |= DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME;
|
|
}
|
|
|
|
if (bitmap != s->prev_bitmap) {
|
|
s->prev_bitmap = bitmap;
|
|
flags |= DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME;
|
|
}
|
|
|
|
qemu_put_bitmap_flags(f, flags);
|
|
|
|
if (flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) {
|
|
qemu_put_counted_string(f, dbms->node_name);
|
|
}
|
|
|
|
if (flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) {
|
|
qemu_put_counted_string(f, bdrv_dirty_bitmap_name(bitmap));
|
|
}
|
|
}
|
|
|
|
static void send_bitmap_start(QEMUFile *f, DBMSaveState *s,
|
|
SaveBitmapState *dbms)
|
|
{
|
|
send_bitmap_header(f, s, dbms, DIRTY_BITMAP_MIG_FLAG_START);
|
|
qemu_put_be32(f, bdrv_dirty_bitmap_granularity(dbms->bitmap));
|
|
qemu_put_byte(f, dbms->flags);
|
|
}
|
|
|
|
static void send_bitmap_complete(QEMUFile *f, DBMSaveState *s,
|
|
SaveBitmapState *dbms)
|
|
{
|
|
send_bitmap_header(f, s, dbms, DIRTY_BITMAP_MIG_FLAG_COMPLETE);
|
|
}
|
|
|
|
static void send_bitmap_bits(QEMUFile *f, DBMSaveState *s,
|
|
SaveBitmapState *dbms,
|
|
uint64_t start_sector, uint32_t nr_sectors)
|
|
{
|
|
/* align for buffer_is_zero() */
|
|
uint64_t align = 4 * sizeof(long);
|
|
uint64_t unaligned_size =
|
|
bdrv_dirty_bitmap_serialization_size(
|
|
dbms->bitmap, start_sector << BDRV_SECTOR_BITS,
|
|
(uint64_t)nr_sectors << BDRV_SECTOR_BITS);
|
|
uint64_t buf_size = QEMU_ALIGN_UP(unaligned_size, align);
|
|
uint8_t *buf = g_malloc0(buf_size);
|
|
uint32_t flags = DIRTY_BITMAP_MIG_FLAG_BITS;
|
|
|
|
bdrv_dirty_bitmap_serialize_part(
|
|
dbms->bitmap, buf, start_sector << BDRV_SECTOR_BITS,
|
|
(uint64_t)nr_sectors << BDRV_SECTOR_BITS);
|
|
|
|
if (buffer_is_zero(buf, buf_size)) {
|
|
g_free(buf);
|
|
buf = NULL;
|
|
flags |= DIRTY_BITMAP_MIG_FLAG_ZEROES;
|
|
}
|
|
|
|
trace_send_bitmap_bits(flags, start_sector, nr_sectors, buf_size);
|
|
|
|
send_bitmap_header(f, s, dbms, flags);
|
|
|
|
qemu_put_be64(f, start_sector);
|
|
qemu_put_be32(f, nr_sectors);
|
|
|
|
/* if a block is zero we need to flush here since the network
|
|
* bandwidth is now a lot higher than the storage device bandwidth.
|
|
* thus if we queue zero blocks we slow down the migration. */
|
|
if (flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) {
|
|
qemu_fflush(f);
|
|
} else {
|
|
qemu_put_be64(f, buf_size);
|
|
qemu_put_buffer(f, buf, buf_size);
|
|
}
|
|
|
|
g_free(buf);
|
|
}
|
|
|
|
/* Called with iothread lock taken. */
|
|
static void dirty_bitmap_do_save_cleanup(DBMSaveState *s)
|
|
{
|
|
SaveBitmapState *dbms;
|
|
|
|
while ((dbms = QSIMPLEQ_FIRST(&s->dbms_list)) != NULL) {
|
|
QSIMPLEQ_REMOVE_HEAD(&s->dbms_list, entry);
|
|
bdrv_dirty_bitmap_set_busy(dbms->bitmap, false);
|
|
bdrv_unref(dbms->bs);
|
|
g_free(dbms);
|
|
}
|
|
}
|
|
|
|
/* Called with iothread lock taken. */
|
|
static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs,
|
|
const char *bs_name)
|
|
{
|
|
BdrvDirtyBitmap *bitmap;
|
|
SaveBitmapState *dbms;
|
|
Error *local_err = NULL;
|
|
|
|
FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
|
|
if (bdrv_dirty_bitmap_name(bitmap)) {
|
|
break;
|
|
}
|
|
}
|
|
if (!bitmap) {
|
|
return 0;
|
|
}
|
|
|
|
if (!bs_name || strcmp(bs_name, "") == 0) {
|
|
error_report("Bitmap '%s' in unnamed node can't be migrated",
|
|
bdrv_dirty_bitmap_name(bitmap));
|
|
return -1;
|
|
}
|
|
|
|
if (bs_name[0] == '#') {
|
|
error_report("Bitmap '%s' in a node with auto-generated "
|
|
"name '%s' can't be migrated",
|
|
bdrv_dirty_bitmap_name(bitmap), bs_name);
|
|
return -1;
|
|
}
|
|
|
|
FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
|
|
if (!bdrv_dirty_bitmap_name(bitmap)) {
|
|
continue;
|
|
}
|
|
|
|
if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, &local_err)) {
|
|
error_report_err(local_err);
|
|
return -1;
|
|
}
|
|
|
|
bdrv_ref(bs);
|
|
bdrv_dirty_bitmap_set_busy(bitmap, true);
|
|
|
|
dbms = g_new0(SaveBitmapState, 1);
|
|
dbms->bs = bs;
|
|
dbms->node_name = bs_name;
|
|
dbms->bitmap = bitmap;
|
|
dbms->total_sectors = bdrv_nb_sectors(bs);
|
|
dbms->sectors_per_chunk = CHUNK_SIZE * 8 *
|
|
bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
|
|
if (bdrv_dirty_bitmap_enabled(bitmap)) {
|
|
dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
|
|
}
|
|
if (bdrv_dirty_bitmap_get_persistence(bitmap)) {
|
|
dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT;
|
|
}
|
|
|
|
QSIMPLEQ_INSERT_TAIL(&s->dbms_list, dbms, entry);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Called with iothread lock taken. */
|
|
static int init_dirty_bitmap_migration(DBMSaveState *s)
|
|
{
|
|
BlockDriverState *bs;
|
|
SaveBitmapState *dbms;
|
|
GHashTable *handled_by_blk = g_hash_table_new(NULL, NULL);
|
|
BlockBackend *blk;
|
|
|
|
s->bulk_completed = false;
|
|
s->prev_bs = NULL;
|
|
s->prev_bitmap = NULL;
|
|
s->no_bitmaps = false;
|
|
|
|
/*
|
|
* Use blockdevice name for direct (or filtered) children of named block
|
|
* backends.
|
|
*/
|
|
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
|
|
const char *name = blk_name(blk);
|
|
|
|
if (!name || strcmp(name, "") == 0) {
|
|
continue;
|
|
}
|
|
|
|
bs = blk_bs(blk);
|
|
|
|
/* Skip filters without bitmaps */
|
|
while (bs && bs->drv && bs->drv->is_filter &&
|
|
!bdrv_has_named_bitmaps(bs))
|
|
{
|
|
if (bs->backing) {
|
|
bs = bs->backing->bs;
|
|
} else if (bs->file) {
|
|
bs = bs->file->bs;
|
|
} else {
|
|
bs = NULL;
|
|
}
|
|
}
|
|
|
|
if (bs && bs->drv && !bs->drv->is_filter) {
|
|
if (add_bitmaps_to_list(s, bs, name)) {
|
|
goto fail;
|
|
}
|
|
g_hash_table_add(handled_by_blk, bs);
|
|
}
|
|
}
|
|
|
|
for (bs = bdrv_next_all_states(NULL); bs; bs = bdrv_next_all_states(bs)) {
|
|
if (g_hash_table_contains(handled_by_blk, bs)) {
|
|
continue;
|
|
}
|
|
|
|
if (add_bitmaps_to_list(s, bs, bdrv_get_node_name(bs))) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
/* unset migration flags here, to not roll back it */
|
|
QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
|
|
bdrv_dirty_bitmap_skip_store(dbms->bitmap, true);
|
|
}
|
|
|
|
if (QSIMPLEQ_EMPTY(&s->dbms_list)) {
|
|
s->no_bitmaps = true;
|
|
}
|
|
|
|
g_hash_table_destroy(handled_by_blk);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
g_hash_table_destroy(handled_by_blk);
|
|
dirty_bitmap_do_save_cleanup(s);
|
|
|
|
return -1;
|
|
}
|
|
|
|
/* Called with no lock taken. */
|
|
static void bulk_phase_send_chunk(QEMUFile *f, DBMSaveState *s,
|
|
SaveBitmapState *dbms)
|
|
{
|
|
uint32_t nr_sectors = MIN(dbms->total_sectors - dbms->cur_sector,
|
|
dbms->sectors_per_chunk);
|
|
|
|
send_bitmap_bits(f, s, dbms, dbms->cur_sector, nr_sectors);
|
|
|
|
dbms->cur_sector += nr_sectors;
|
|
if (dbms->cur_sector >= dbms->total_sectors) {
|
|
dbms->bulk_completed = true;
|
|
}
|
|
}
|
|
|
|
/* Called with no lock taken. */
|
|
static void bulk_phase(QEMUFile *f, DBMSaveState *s, bool limit)
|
|
{
|
|
SaveBitmapState *dbms;
|
|
|
|
QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
|
|
while (!dbms->bulk_completed) {
|
|
bulk_phase_send_chunk(f, s, dbms);
|
|
if (limit && qemu_file_rate_limit(f)) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
s->bulk_completed = true;
|
|
}
|
|
|
|
/* for SaveVMHandlers */
|
|
static void dirty_bitmap_save_cleanup(void *opaque)
|
|
{
|
|
DBMSaveState *s = &((DBMState *)opaque)->save;
|
|
|
|
dirty_bitmap_do_save_cleanup(s);
|
|
}
|
|
|
|
static int dirty_bitmap_save_iterate(QEMUFile *f, void *opaque)
|
|
{
|
|
DBMSaveState *s = &((DBMState *)opaque)->save;
|
|
|
|
trace_dirty_bitmap_save_iterate(migration_in_postcopy());
|
|
|
|
if (migration_in_postcopy() && !s->bulk_completed) {
|
|
bulk_phase(f, s, true);
|
|
}
|
|
|
|
qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS);
|
|
|
|
return s->bulk_completed;
|
|
}
|
|
|
|
/* Called with iothread lock taken. */
|
|
|
|
static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque)
|
|
{
|
|
DBMSaveState *s = &((DBMState *)opaque)->save;
|
|
SaveBitmapState *dbms;
|
|
trace_dirty_bitmap_save_complete_enter();
|
|
|
|
if (!s->bulk_completed) {
|
|
bulk_phase(f, s, false);
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
|
|
send_bitmap_complete(f, s, dbms);
|
|
}
|
|
|
|
qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS);
|
|
|
|
trace_dirty_bitmap_save_complete_finish();
|
|
|
|
dirty_bitmap_save_cleanup(opaque);
|
|
return 0;
|
|
}
|
|
|
|
static void dirty_bitmap_save_pending(QEMUFile *f, void *opaque,
|
|
uint64_t max_size,
|
|
uint64_t *res_precopy_only,
|
|
uint64_t *res_compatible,
|
|
uint64_t *res_postcopy_only)
|
|
{
|
|
DBMSaveState *s = &((DBMState *)opaque)->save;
|
|
SaveBitmapState *dbms;
|
|
uint64_t pending = 0;
|
|
|
|
qemu_mutex_lock_iothread();
|
|
|
|
QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
|
|
uint64_t gran = bdrv_dirty_bitmap_granularity(dbms->bitmap);
|
|
uint64_t sectors = dbms->bulk_completed ? 0 :
|
|
dbms->total_sectors - dbms->cur_sector;
|
|
|
|
pending += DIV_ROUND_UP(sectors * BDRV_SECTOR_SIZE, gran);
|
|
}
|
|
|
|
qemu_mutex_unlock_iothread();
|
|
|
|
trace_dirty_bitmap_save_pending(pending, max_size);
|
|
|
|
*res_postcopy_only += pending;
|
|
}
|
|
|
|
/* First occurrence of this bitmap. It should be created if doesn't exist */
|
|
static int dirty_bitmap_load_start(QEMUFile *f, DBMLoadState *s)
|
|
{
|
|
Error *local_err = NULL;
|
|
uint32_t granularity = qemu_get_be32(f);
|
|
uint8_t flags = qemu_get_byte(f);
|
|
LoadBitmapState *b;
|
|
|
|
if (s->cancelled) {
|
|
return 0;
|
|
}
|
|
|
|
if (s->bitmap) {
|
|
error_report("Bitmap with the same name ('%s') already exists on "
|
|
"destination", bdrv_dirty_bitmap_name(s->bitmap));
|
|
return -EINVAL;
|
|
} else {
|
|
s->bitmap = bdrv_create_dirty_bitmap(s->bs, granularity,
|
|
s->bitmap_name, &local_err);
|
|
if (!s->bitmap) {
|
|
error_report_err(local_err);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (flags & DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK) {
|
|
error_report("Unknown flags in migrated dirty bitmap header: %x",
|
|
flags);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (flags & DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT) {
|
|
bdrv_dirty_bitmap_set_persistence(s->bitmap, true);
|
|
}
|
|
|
|
bdrv_disable_dirty_bitmap(s->bitmap);
|
|
if (flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED) {
|
|
bdrv_dirty_bitmap_create_successor(s->bitmap, &local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
b = g_new(LoadBitmapState, 1);
|
|
b->bs = s->bs;
|
|
b->bitmap = s->bitmap;
|
|
b->migrated = false;
|
|
b->enabled = flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
|
|
|
|
s->bitmaps = g_slist_prepend(s->bitmaps, b);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* before_vm_start_handle_item
|
|
*
|
|
* g_slist_foreach helper
|
|
*
|
|
* item is LoadBitmapState*
|
|
* opaque is DBMLoadState*
|
|
*/
|
|
static void before_vm_start_handle_item(void *item, void *opaque)
|
|
{
|
|
DBMLoadState *s = opaque;
|
|
LoadBitmapState *b = item;
|
|
|
|
if (b->enabled) {
|
|
if (b->migrated) {
|
|
bdrv_enable_dirty_bitmap(b->bitmap);
|
|
} else {
|
|
bdrv_dirty_bitmap_enable_successor(b->bitmap);
|
|
}
|
|
}
|
|
|
|
if (b->migrated) {
|
|
s->bitmaps = g_slist_remove(s->bitmaps, b);
|
|
g_free(b);
|
|
}
|
|
}
|
|
|
|
void dirty_bitmap_mig_before_vm_start(void)
|
|
{
|
|
DBMLoadState *s = &dbm_state.load;
|
|
qemu_mutex_lock(&s->lock);
|
|
|
|
assert(!s->before_vm_start_handled);
|
|
g_slist_foreach(s->bitmaps, before_vm_start_handle_item, s);
|
|
s->before_vm_start_handled = true;
|
|
|
|
qemu_mutex_unlock(&s->lock);
|
|
}
|
|
|
|
static void cancel_incoming_locked(DBMLoadState *s)
|
|
{
|
|
GSList *item;
|
|
|
|
if (s->cancelled) {
|
|
return;
|
|
}
|
|
|
|
s->cancelled = true;
|
|
s->bs = NULL;
|
|
s->bitmap = NULL;
|
|
|
|
/* Drop all unfinished bitmaps */
|
|
for (item = s->bitmaps; item; item = g_slist_next(item)) {
|
|
LoadBitmapState *b = item->data;
|
|
|
|
/*
|
|
* Bitmap must be unfinished, as finished bitmaps should already be
|
|
* removed from the list.
|
|
*/
|
|
assert(!s->before_vm_start_handled || !b->migrated);
|
|
if (bdrv_dirty_bitmap_has_successor(b->bitmap)) {
|
|
bdrv_reclaim_dirty_bitmap(b->bitmap, &error_abort);
|
|
}
|
|
bdrv_release_dirty_bitmap(b->bitmap);
|
|
}
|
|
|
|
g_slist_free_full(s->bitmaps, g_free);
|
|
s->bitmaps = NULL;
|
|
}
|
|
|
|
void dirty_bitmap_mig_cancel_outgoing(void)
|
|
{
|
|
dirty_bitmap_do_save_cleanup(&dbm_state.save);
|
|
}
|
|
|
|
void dirty_bitmap_mig_cancel_incoming(void)
|
|
{
|
|
DBMLoadState *s = &dbm_state.load;
|
|
|
|
qemu_mutex_lock(&s->lock);
|
|
|
|
cancel_incoming_locked(s);
|
|
|
|
qemu_mutex_unlock(&s->lock);
|
|
}
|
|
|
|
static void dirty_bitmap_load_complete(QEMUFile *f, DBMLoadState *s)
|
|
{
|
|
GSList *item;
|
|
trace_dirty_bitmap_load_complete();
|
|
|
|
if (s->cancelled) {
|
|
return;
|
|
}
|
|
|
|
bdrv_dirty_bitmap_deserialize_finish(s->bitmap);
|
|
|
|
if (bdrv_dirty_bitmap_has_successor(s->bitmap)) {
|
|
bdrv_reclaim_dirty_bitmap(s->bitmap, &error_abort);
|
|
}
|
|
|
|
for (item = s->bitmaps; item; item = g_slist_next(item)) {
|
|
LoadBitmapState *b = item->data;
|
|
|
|
if (b->bitmap == s->bitmap) {
|
|
b->migrated = true;
|
|
if (s->before_vm_start_handled) {
|
|
s->bitmaps = g_slist_remove(s->bitmaps, b);
|
|
g_free(b);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int dirty_bitmap_load_bits(QEMUFile *f, DBMLoadState *s)
|
|
{
|
|
uint64_t first_byte = qemu_get_be64(f) << BDRV_SECTOR_BITS;
|
|
uint64_t nr_bytes = (uint64_t)qemu_get_be32(f) << BDRV_SECTOR_BITS;
|
|
trace_dirty_bitmap_load_bits_enter(first_byte >> BDRV_SECTOR_BITS,
|
|
nr_bytes >> BDRV_SECTOR_BITS);
|
|
|
|
if (s->flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) {
|
|
trace_dirty_bitmap_load_bits_zeroes();
|
|
if (!s->cancelled) {
|
|
bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte,
|
|
nr_bytes, false);
|
|
}
|
|
} else {
|
|
size_t ret;
|
|
g_autofree uint8_t *buf = NULL;
|
|
uint64_t buf_size = qemu_get_be64(f);
|
|
uint64_t needed_size;
|
|
|
|
/*
|
|
* The actual check for buf_size is done a bit later. We can't do it in
|
|
* cancelled mode as we don't have the bitmap to check the constraints
|
|
* (so, we allocate a buffer and read prior to the check). On the other
|
|
* hand, we shouldn't blindly g_malloc the number from the stream.
|
|
* Actually one chunk should not be larger than CHUNK_SIZE. Let's allow
|
|
* a bit larger (which means that bitmap migration will fail anyway and
|
|
* the whole migration will most probably fail soon due to broken
|
|
* stream).
|
|
*/
|
|
if (buf_size > 10 * CHUNK_SIZE) {
|
|
error_report("Bitmap migration stream buffer allocation request "
|
|
"is too large");
|
|
return -EIO;
|
|
}
|
|
|
|
buf = g_malloc(buf_size);
|
|
ret = qemu_get_buffer(f, buf, buf_size);
|
|
if (ret != buf_size) {
|
|
error_report("Failed to read bitmap bits");
|
|
return -EIO;
|
|
}
|
|
|
|
if (s->cancelled) {
|
|
return 0;
|
|
}
|
|
|
|
needed_size = bdrv_dirty_bitmap_serialization_size(s->bitmap,
|
|
first_byte,
|
|
nr_bytes);
|
|
|
|
if (needed_size > buf_size ||
|
|
buf_size > QEMU_ALIGN_UP(needed_size, 4 * sizeof(long))
|
|
/* Here used same alignment as in send_bitmap_bits */
|
|
) {
|
|
error_report("Migrated bitmap granularity doesn't "
|
|
"match the destination bitmap '%s' granularity",
|
|
bdrv_dirty_bitmap_name(s->bitmap));
|
|
cancel_incoming_locked(s);
|
|
return 0;
|
|
}
|
|
|
|
bdrv_dirty_bitmap_deserialize_part(s->bitmap, buf, first_byte, nr_bytes,
|
|
false);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s)
|
|
{
|
|
Error *local_err = NULL;
|
|
bool nothing;
|
|
s->flags = qemu_get_bitmap_flags(f);
|
|
trace_dirty_bitmap_load_header(s->flags);
|
|
|
|
nothing = s->flags == (s->flags & DIRTY_BITMAP_MIG_FLAG_EOS);
|
|
|
|
if (s->flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) {
|
|
if (!qemu_get_counted_string(f, s->node_name)) {
|
|
error_report("Unable to read node name string");
|
|
return -EINVAL;
|
|
}
|
|
if (!s->cancelled) {
|
|
s->bs = bdrv_lookup_bs(s->node_name, s->node_name, &local_err);
|
|
if (!s->bs) {
|
|
error_report_err(local_err);
|
|
cancel_incoming_locked(s);
|
|
}
|
|
}
|
|
} else if (!s->bs && !nothing && !s->cancelled) {
|
|
error_report("Error: block device name is not set");
|
|
cancel_incoming_locked(s);
|
|
}
|
|
|
|
if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) {
|
|
if (!qemu_get_counted_string(f, s->bitmap_name)) {
|
|
error_report("Unable to read bitmap name string");
|
|
return -EINVAL;
|
|
}
|
|
if (!s->cancelled) {
|
|
s->bitmap = bdrv_find_dirty_bitmap(s->bs, s->bitmap_name);
|
|
|
|
/*
|
|
* bitmap may be NULL here, it wouldn't be an error if it is the
|
|
* first occurrence of the bitmap
|
|
*/
|
|
if (!s->bitmap && !(s->flags & DIRTY_BITMAP_MIG_FLAG_START)) {
|
|
error_report("Error: unknown dirty bitmap "
|
|
"'%s' for block device '%s'",
|
|
s->bitmap_name, s->node_name);
|
|
cancel_incoming_locked(s);
|
|
}
|
|
}
|
|
} else if (!s->bitmap && !nothing && !s->cancelled) {
|
|
error_report("Error: block device name is not set");
|
|
cancel_incoming_locked(s);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* dirty_bitmap_load
|
|
*
|
|
* Load sequence of dirty bitmap chunks. Return error only on fatal io stream
|
|
* violations. On other errors just cancel bitmaps incoming migration and return
|
|
* 0.
|
|
*
|
|
* Note, than when incoming bitmap migration is canceled, we still must read all
|
|
* our chunks (and just ignore them), to not affect other migration objects.
|
|
*/
|
|
static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id)
|
|
{
|
|
DBMLoadState *s = &((DBMState *)opaque)->load;
|
|
int ret = 0;
|
|
|
|
trace_dirty_bitmap_load_enter();
|
|
|
|
if (version_id != 1) {
|
|
QEMU_LOCK_GUARD(&s->lock);
|
|
cancel_incoming_locked(s);
|
|
return -EINVAL;
|
|
}
|
|
|
|
do {
|
|
QEMU_LOCK_GUARD(&s->lock);
|
|
|
|
ret = dirty_bitmap_load_header(f, s);
|
|
if (ret < 0) {
|
|
cancel_incoming_locked(s);
|
|
return ret;
|
|
}
|
|
|
|
if (s->flags & DIRTY_BITMAP_MIG_FLAG_START) {
|
|
ret = dirty_bitmap_load_start(f, s);
|
|
} else if (s->flags & DIRTY_BITMAP_MIG_FLAG_COMPLETE) {
|
|
dirty_bitmap_load_complete(f, s);
|
|
} else if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITS) {
|
|
ret = dirty_bitmap_load_bits(f, s);
|
|
}
|
|
|
|
if (!ret) {
|
|
ret = qemu_file_get_error(f);
|
|
}
|
|
|
|
if (ret) {
|
|
cancel_incoming_locked(s);
|
|
return ret;
|
|
}
|
|
} while (!(s->flags & DIRTY_BITMAP_MIG_FLAG_EOS));
|
|
|
|
trace_dirty_bitmap_load_success();
|
|
return 0;
|
|
}
|
|
|
|
static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque)
|
|
{
|
|
DBMSaveState *s = &((DBMState *)opaque)->save;
|
|
SaveBitmapState *dbms = NULL;
|
|
if (init_dirty_bitmap_migration(s) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
|
|
send_bitmap_start(f, s, dbms);
|
|
}
|
|
qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool dirty_bitmap_is_active(void *opaque)
|
|
{
|
|
DBMSaveState *s = &((DBMState *)opaque)->save;
|
|
|
|
return migrate_dirty_bitmaps() && !s->no_bitmaps;
|
|
}
|
|
|
|
static bool dirty_bitmap_is_active_iterate(void *opaque)
|
|
{
|
|
return dirty_bitmap_is_active(opaque) && !runstate_is_running();
|
|
}
|
|
|
|
static bool dirty_bitmap_has_postcopy(void *opaque)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
static SaveVMHandlers savevm_dirty_bitmap_handlers = {
|
|
.save_setup = dirty_bitmap_save_setup,
|
|
.save_live_complete_postcopy = dirty_bitmap_save_complete,
|
|
.save_live_complete_precopy = dirty_bitmap_save_complete,
|
|
.has_postcopy = dirty_bitmap_has_postcopy,
|
|
.save_live_pending = dirty_bitmap_save_pending,
|
|
.save_live_iterate = dirty_bitmap_save_iterate,
|
|
.is_active_iterate = dirty_bitmap_is_active_iterate,
|
|
.load_state = dirty_bitmap_load,
|
|
.save_cleanup = dirty_bitmap_save_cleanup,
|
|
.is_active = dirty_bitmap_is_active,
|
|
};
|
|
|
|
void dirty_bitmap_mig_init(void)
|
|
{
|
|
QSIMPLEQ_INIT(&dbm_state.save.dbms_list);
|
|
qemu_mutex_init(&dbm_state.load.lock);
|
|
|
|
register_savevm_live("dirty-bitmap", 0, 1,
|
|
&savevm_dirty_bitmap_handlers,
|
|
&dbm_state);
|
|
}
|