* Juan Quintela (quint...@redhat.com) wrote:
> Both the ram bitmap and the unsent bitmap are split by RAMBlock.
>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
> ---
> include/exec/ram_addr.h | 13 ++-
> include/migration/postcopy-ram.h | 3 -
> migration/postcopy-ram.c | 5 +-
> migration/ram.c | 215
> +++++++++++++++------------------------
> 4 files changed, 91 insertions(+), 145 deletions(-)
>
> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> index c9ddcd0..75dccb6 100644
> --- a/include/exec/ram_addr.h
> +++ b/include/exec/ram_addr.h
> @@ -39,6 +39,14 @@ struct RAMBlock {
> QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
> int fd;
> size_t page_size;
> + /* dirty bitmap used during migration */
> + unsigned long *bmap;
> + /* bitmap of pages that haven't been sent even once
> + * only maintained and used in postcopy at the moment
> + * where it's used to send the dirtymap at the start
> + * of the postcopy phase
> + */
> + unsigned long *unsentmap;
> };
>
> static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
> @@ -353,16 +361,15 @@ static inline void
> cpu_physical_memory_clear_dirty_range(ram_addr_t start,
>
>
> static inline
> -uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest,
> - RAMBlock *rb,
> +uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
> ram_addr_t start,
> ram_addr_t length,
> uint64_t *real_dirty_pages)
> {
> ram_addr_t addr;
> - start = rb->offset + start;
> unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
> uint64_t num_dirty = 0;
> + unsigned long *dest = rb->bmap;
>
> /* start address is aligned at the start of a word? */
> if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {
> diff --git a/include/migration/postcopy-ram.h
> b/include/migration/postcopy-ram.h
> index 8e036b9..4c25f03 100644
> --- a/include/migration/postcopy-ram.h
> +++ b/include/migration/postcopy-ram.h
> @@ -43,12 +43,9 @@ int postcopy_ram_prepare_discard(MigrationIncomingState
> *mis);
>
> /*
> * Called at the start of each RAMBlock by the bitmap code.
> - * 'offset' is the bitmap offset of the named RAMBlock in the migration
> - * bitmap.
> * Returns a new PDS
> */
> PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
> - unsigned long offset,
> const char *name);
>
> /*
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index 85fd8d7..e3f4a37 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -33,7 +33,6 @@
>
> struct PostcopyDiscardState {
> const char *ramblock_name;
> - uint64_t offset; /* Bitmap entry for the 1st bit of this RAMBlock */
> uint16_t cur_entry;
> /*
> * Start and length of a discard range (bytes)
> @@ -717,14 +716,12 @@ void *postcopy_get_tmp_page(MigrationIncomingState *mis)
> * returns: a new PDS.
> */
> PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
> - unsigned long offset,
> const char *name)
> {
> PostcopyDiscardState *res = g_malloc0(sizeof(PostcopyDiscardState));
>
> if (res) {
> res->ramblock_name = name;
> - res->offset = offset;
> }
>
> return res;
> @@ -745,7 +742,7 @@ void postcopy_discard_send_range(MigrationState *ms,
> PostcopyDiscardState *pds,
> {
> size_t tp_size = qemu_target_page_size();
> /* Convert to byte offsets within the RAM block */
> - pds->start_list[pds->cur_entry] = (start - pds->offset) * tp_size;
> + pds->start_list[pds->cur_entry] = start * tp_size;
> pds->length_list[pds->cur_entry] = length * tp_size;
> trace_postcopy_discard_send_range(pds->ramblock_name, start, length);
> pds->cur_entry++;
> diff --git a/migration/ram.c b/migration/ram.c
> index f48664e..1dc1749 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -138,19 +138,6 @@ out:
> return ret;
> }
>
> -struct RAMBitmap {
> - struct rcu_head rcu;
> - /* Main migration bitmap */
> - unsigned long *bmap;
> - /* bitmap of pages that haven't been sent even once
> - * only maintained and used in postcopy at the moment
> - * where it's used to send the dirtymap at the start
> - * of the postcopy phase
> - */
> - unsigned long *unsentmap;
> -};
> -typedef struct RAMBitmap RAMBitmap;
> -
> /*
> * An outstanding page request, on the source, having been received
> * and queued
> @@ -220,8 +207,6 @@ struct RAMState {
> uint64_t postcopy_requests;
> /* protects modification of the bitmap */
> QemuMutex bitmap_mutex;
> - /* Ram Bitmap protected by RCU */
> - RAMBitmap *ram_bitmap;
> /* The RAMBlock used in the last src_page_requests */
> RAMBlock *last_req_rb;
> /* Queue of outstanding page requests from the destination */
> @@ -614,22 +599,17 @@ static inline
> unsigned long migration_bitmap_find_dirty(RAMState *rs, RAMBlock *rb,
> unsigned long start)
> {
> - unsigned long base = rb->offset >> TARGET_PAGE_BITS;
> - unsigned long nr = base + start;
> - uint64_t rb_size = rb->used_length;
> - unsigned long size = base + (rb_size >> TARGET_PAGE_BITS);
> - unsigned long *bitmap;
> -
> + unsigned long size = rb->used_length >> TARGET_PAGE_BITS;
> + unsigned long *bitmap = rb->bmap;
> unsigned long next;
>
> - bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> - if (rs->ram_bulk_stage && nr > base) {
> - next = nr + 1;
> + if (rs->ram_bulk_stage && start > 0) {
> + next = start + 1;
> } else {
> - next = find_next_bit(bitmap, size, nr);
> + next = find_next_bit(bitmap, size, start);
> }
>
> - return next - base;
> + return next;
> }
>
> static inline bool migration_bitmap_clear_dirty(RAMState *rs,
> @@ -637,10 +617,8 @@ static inline bool migration_bitmap_clear_dirty(RAMState
> *rs,
> unsigned long page)
> {
> bool ret;
> - unsigned long *bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> - unsigned long nr = (rb->offset >> TARGET_PAGE_BITS) + page;
>
> - ret = test_and_clear_bit(nr, bitmap);
> + ret = test_and_clear_bit(page, rb->bmap);
>
> if (ret) {
> rs->migration_dirty_pages--;
> @@ -651,10 +629,8 @@ static inline bool migration_bitmap_clear_dirty(RAMState
> *rs,
> static void migration_bitmap_sync_range(RAMState *rs, RAMBlock *rb,
> ram_addr_t start, ram_addr_t length)
> {
> - unsigned long *bitmap;
> - bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> rs->migration_dirty_pages +=
> - cpu_physical_memory_sync_dirty_bitmap(bitmap, rb, start, length,
> + cpu_physical_memory_sync_dirty_bitmap(rb, start, length,
> &rs->num_dirty_pages_period);
> }
>
> @@ -1153,17 +1129,13 @@ static bool get_queued_page(RAMState *rs,
> PageSearchStatus *pss)
> * search already sent it.
> */
> if (block) {
> - unsigned long *bitmap;
> unsigned long page;
>
> - bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> - page = (block->offset + offset) >> TARGET_PAGE_BITS;
> - dirty = test_bit(page, bitmap);
> + page = offset >> TARGET_PAGE_BITS;
> + dirty = test_bit(page, block->bmap);
> if (!dirty) {
> trace_get_queued_page_not_dirty(block->idstr,
> (uint64_t)offset,
> - page,
> - test_bit(page,
> - atomic_rcu_read(&rs->ram_bitmap)->unsentmap));
> + page, test_bit(page, block->unsentmap));
> } else {
> trace_get_queued_page(block->idstr, (uint64_t)offset, page);
> }
> @@ -1301,16 +1273,13 @@ static int ram_save_target_page(RAMState *rs,
> PageSearchStatus *pss,
>
> /* Check the pages is dirty and if it is send it */
> if (migration_bitmap_clear_dirty(rs, pss->block, pss->page)) {
> - unsigned long *unsentmap;
> /*
> * If xbzrle is on, stop using the data compression after first
> * round of migration even if compression is enabled. In theory,
> * xbzrle can do better than compression.
> */
> - unsigned long page =
> - (pss->block->offset >> TARGET_PAGE_BITS) + pss->page;
> - if (migrate_use_compression()
> - && (rs->ram_bulk_stage || !migrate_use_xbzrle())) {
> + if (migrate_use_compression() &&
> + (rs->ram_bulk_stage || !migrate_use_xbzrle())) {
> res = ram_save_compressed_page(rs, pss, last_stage);
> } else {
> res = ram_save_page(rs, pss, last_stage);
> @@ -1319,9 +1288,8 @@ static int ram_save_target_page(RAMState *rs,
> PageSearchStatus *pss,
> if (res < 0) {
> return res;
> }
> - unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
> - if (unsentmap) {
> - clear_bit(page, unsentmap);
> + if (pss->block->unsentmap) {
> + clear_bit(pss->page, pss->block->unsentmap);
> }
> }
>
> @@ -1451,25 +1419,20 @@ void free_xbzrle_decoded_buf(void)
> xbzrle_decoded_buf = NULL;
> }
>
> -static void migration_bitmap_free(RAMBitmap *bmap)
> -{
> - g_free(bmap->bmap);
> - g_free(bmap->unsentmap);
> - g_free(bmap);
> -}
> -
> static void ram_migration_cleanup(void *opaque)
> {
> - RAMState *rs = opaque;
> + RAMBlock *block;
>
> /* caller have hold iothread lock or is in a bh, so there is
> * no writing race against this migration_bitmap
> */
> - RAMBitmap *bitmap = rs->ram_bitmap;
> - atomic_rcu_set(&rs->ram_bitmap, NULL);
> - if (bitmap) {
> - memory_global_dirty_log_stop();
> - call_rcu(bitmap, migration_bitmap_free, rcu);
> + memory_global_dirty_log_stop();
> +
> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> + g_free(block->bmap);
> + block->bmap = NULL;
> + g_free(block->unsentmap);
> + block->unsentmap = NULL;
> }
>
> XBZRLE_cache_lock();
> @@ -1504,15 +1467,10 @@ static void ram_state_reset(RAMState *rs)
> void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
> {
> unsigned long ram_pages = last_ram_page();
> - RAMState *rs = &ram_state;
> int64_t cur;
> int64_t linelen = 128;
> char linebuf[129];
>
> - if (!todump) {
> - todump = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> - }
> -
> for (cur = 0; cur < ram_pages; cur += linelen) {
> int64_t curb;
> bool found = false;
> @@ -1539,14 +1497,12 @@ void ram_debug_dump_bitmap(unsigned long *todump,
> bool expected)
>
> void ram_postcopy_migrated_memory_release(MigrationState *ms)
> {
> - RAMState *rs = &ram_state;
> struct RAMBlock *block;
> - unsigned long *bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
>
> QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> - unsigned long first = block->offset >> TARGET_PAGE_BITS;
> - unsigned long range = first + (block->used_length >>
> TARGET_PAGE_BITS);
> - unsigned long run_start = find_next_zero_bit(bitmap, range, first);
> + unsigned long *bitmap = block->bmap;
> + unsigned long range = block->used_length >> TARGET_PAGE_BITS;
> + unsigned long run_start = find_next_zero_bit(bitmap, range, 0);
>
> while (run_start < range) {
> unsigned long run_end = find_next_bit(bitmap, range, run_start +
> 1);
> @@ -1573,16 +1529,13 @@ void
> ram_postcopy_migrated_memory_release(MigrationState *ms)
> */
> static int postcopy_send_discard_bm_ram(MigrationState *ms,
> PostcopyDiscardState *pds,
> - unsigned long start,
> - unsigned long length)
> + RAMBlock *block)
> {
> - RAMState *rs = &ram_state;
> - unsigned long end = start + length; /* one after the end */
> + unsigned long end = block->used_length >> TARGET_PAGE_BITS;
> unsigned long current;
> - unsigned long *unsentmap;
> + unsigned long *unsentmap = block->unsentmap;
>
> - unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
> - for (current = start; current < end; ) {
> + for (current = 0; current < end; ) {
> unsigned long one = find_next_bit(unsentmap, end, current);
>
> if (one <= end) {
> @@ -1625,18 +1578,15 @@ static int
> postcopy_each_ram_send_discard(MigrationState *ms)
> int ret;
>
> QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> - unsigned long first = block->offset >> TARGET_PAGE_BITS;
> - PostcopyDiscardState *pds = postcopy_discard_send_init(ms,
> - first,
> - block->idstr);
> + PostcopyDiscardState *pds =
> + postcopy_discard_send_init(ms, block->idstr);
>
> /*
> * Postcopy sends chunks of bitmap over the wire, but it
> * just needs indexes at this point, avoids it having
> * target page specific code.
> */
> - ret = postcopy_send_discard_bm_ram(ms, pds, first,
> - block->used_length >> TARGET_PAGE_BITS);
> + ret = postcopy_send_discard_bm_ram(ms, pds, block);
> postcopy_discard_send_finish(ms, pds);
> if (ret) {
> return ret;
> @@ -1667,12 +1617,10 @@ static void
> postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
> PostcopyDiscardState *pds)
> {
> RAMState *rs = &ram_state;
> - unsigned long *bitmap;
> - unsigned long *unsentmap;
> + unsigned long *bitmap = block->bmap;
> + unsigned long *unsentmap = block->unsentmap;
> unsigned int host_ratio = block->page_size / TARGET_PAGE_SIZE;
> - unsigned long first = block->offset >> TARGET_PAGE_BITS;
> - unsigned long len = block->used_length >> TARGET_PAGE_BITS;
> - unsigned long last = first + (len - 1);
> + unsigned long pages = block->used_length >> TARGET_PAGE_BITS;
> unsigned long run_start;
>
> if (block->page_size == TARGET_PAGE_SIZE) {
> @@ -1680,18 +1628,15 @@ static void
> postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
> return;
> }
>
> - bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> - unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
> -
> if (unsent_pass) {
> /* Find a sent page */
> - run_start = find_next_zero_bit(unsentmap, last + 1, first);
> + run_start = find_next_zero_bit(unsentmap, pages, 0);
> } else {
> /* Find a dirty page */
> - run_start = find_next_bit(bitmap, last + 1, first);
> + run_start = find_next_bit(bitmap, pages, 0);
> }
>
> - while (run_start <= last) {
> + while (run_start < pages) {
> bool do_fixup = false;
> unsigned long fixup_start_addr;
> unsigned long host_offset;
> @@ -1711,9 +1656,9 @@ static void
> postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
> /* Find the end of this run */
> unsigned long run_end;
> if (unsent_pass) {
> - run_end = find_next_bit(unsentmap, last + 1, run_start + 1);
> + run_end = find_next_bit(unsentmap, pages, run_start + 1);
> } else {
> - run_end = find_next_zero_bit(bitmap, last + 1, run_start +
> 1);
> + run_end = find_next_zero_bit(bitmap, pages, run_start + 1);
> }
> /*
> * If the end isn't at the start of a host page, then the
> @@ -1770,11 +1715,10 @@ static void
> postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
>
> if (unsent_pass) {
> /* Find the next sent page for the next iteration */
> - run_start = find_next_zero_bit(unsentmap, last + 1,
> - run_start);
> + run_start = find_next_zero_bit(unsentmap, pages, run_start);
> } else {
> /* Find the next dirty page for the next iteration */
> - run_start = find_next_bit(bitmap, last + 1, run_start);
> + run_start = find_next_bit(bitmap, pages, run_start);
> }
> }
> }
> @@ -1803,10 +1747,8 @@ static int postcopy_chunk_hostpages(MigrationState *ms)
> rs->last_page = 0;
>
> QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> - unsigned long first = block->offset >> TARGET_PAGE_BITS;
> -
> PostcopyDiscardState *pds =
> - postcopy_discard_send_init(ms, first, block->idstr);
> + postcopy_discard_send_init(ms, block->idstr);
>
> /* First pass: Discard all partially sent host pages */
> postcopy_chunk_hostpages_pass(ms, true, block, pds);
> @@ -1840,39 +1782,41 @@ static int postcopy_chunk_hostpages(MigrationState
> *ms)
> int ram_postcopy_send_discard_bitmap(MigrationState *ms)
> {
> RAMState *rs = &ram_state;
> + RAMBlock *block;
> int ret;
> - unsigned long *bitmap, *unsentmap;
>
> rcu_read_lock();
>
> /* This should be our last sync, the src is now paused */
> migration_bitmap_sync(rs);
>
> - unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
> - if (!unsentmap) {
> - /* We don't have a safe way to resize the sentmap, so
> - * if the bitmap was resized it will be NULL at this
> - * point.
> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> + unsigned long pages = block->used_length >> TARGET_PAGE_BITS;
> + unsigned long *bitmap = block->bmap;
> + unsigned long *unsentmap = block->unsentmap;
> +
> + if (!unsentmap) {
> + /* We don't have a safe way to resize the sentmap, so
> + * if the bitmap was resized it will be NULL at this
> + * point.
> + */
> + error_report("migration ram resized during precopy phase");
> + rcu_read_unlock();
> + return -EINVAL;
> + }
> +
> + /* Deal with TPS != HPS and huge pages */
> + ret = postcopy_chunk_hostpages(ms);
That's odd being on the inside of the RAM FOREACH since it has it's own.
Other than that, I think it's OK.
Dave
> + if (ret) {
> + rcu_read_unlock();
> + return ret;
> + }
> +
> + /*
> + * Update the unsentmap to be unsentmap = unsentmap | dirty
> */
> - error_report("migration ram resized during precopy phase");
> - rcu_read_unlock();
> - return -EINVAL;
> + bitmap_or(unsentmap, unsentmap, bitmap, pages);
> }
> -
> - /* Deal with TPS != HPS and huge pages */
> - ret = postcopy_chunk_hostpages(ms);
> - if (ret) {
> - rcu_read_unlock();
> - return ret;
> - }
> -
> - /*
> - * Update the unsentmap to be unsentmap = unsentmap | dirty
> - */
> - bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
> - bitmap_or(unsentmap, unsentmap, bitmap, last_ram_page());
> -
> -
> trace_ram_postcopy_send_discard_bitmap();
> #ifdef DEBUG_POSTCOPY
> ram_debug_dump_bitmap(unsentmap, true);
> @@ -1918,8 +1862,6 @@ err:
>
> static int ram_state_init(RAMState *rs)
> {
> - unsigned long ram_bitmap_pages;
> -
> memset(rs, 0, sizeof(*rs));
> qemu_mutex_init(&rs->bitmap_mutex);
> qemu_mutex_init(&rs->src_page_req_mutex);
> @@ -1961,16 +1903,19 @@ static int ram_state_init(RAMState *rs)
> rcu_read_lock();
> ram_state_reset(rs);
>
> - rs->ram_bitmap = g_new0(RAMBitmap, 1);
> /* Skip setting bitmap if there is no RAM */
> if (ram_bytes_total()) {
> - ram_bitmap_pages = last_ram_page();
> - rs->ram_bitmap->bmap = bitmap_new(ram_bitmap_pages);
> - bitmap_set(rs->ram_bitmap->bmap, 0, ram_bitmap_pages);
> + RAMBlock *block;
>
> - if (migrate_postcopy_ram()) {
> - rs->ram_bitmap->unsentmap = bitmap_new(ram_bitmap_pages);
> - bitmap_set(rs->ram_bitmap->unsentmap, 0, ram_bitmap_pages);
> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> + unsigned long pages = block->max_length >> TARGET_PAGE_BITS;
> +
> + block->bmap = bitmap_new(pages);
> + bitmap_set(block->bmap, 0, pages);
> + if (migrate_postcopy_ram()) {
> + block->unsentmap = bitmap_new(pages);
> + bitmap_set(block->unsentmap, 0, pages);
> + }
> }
> }
>
> --
> 2.9.3
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
