diff options
Diffstat (limited to 'arch_init.c')
| -rw-r--r-- | arch_init.c | 177 |
1 files changed, 110 insertions, 67 deletions
diff --git a/arch_init.c b/arch_init.c index 691b5e2e91..c3f7d3f56d 100644 --- a/arch_init.c +++ b/arch_init.c @@ -305,34 +305,50 @@ uint64_t xbzrle_mig_pages_overflow(void) return acct_info.xbzrle_overflows; } -static size_t save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset, - int cont, int flag) +/* This is the last block that we have visited serching for dirty pages + */ +static RAMBlock *last_seen_block; +/* This is the last block from where we have sent data */ +static RAMBlock *last_sent_block; +static ram_addr_t last_offset; +static unsigned long *migration_bitmap; +static uint64_t migration_dirty_pages; +static uint32_t last_version; +static bool ram_bulk_stage; + +/** + * save_page_header: Write page header to wire + * + * If this is the 1st block, it also writes the block identification + * + * Returns: Number of bytes written + * + * @f: QEMUFile where to send the data + * @block: block that contains the page we want to send + * @offset: offset inside the block for the page + * in the lower bits, it contains flags + */ +static size_t save_page_header(QEMUFile *f, RAMBlock *block, ram_addr_t offset) { size_t size; - qemu_put_be64(f, offset | cont | flag); + if (block == last_sent_block) { + offset |= RAM_SAVE_FLAG_CONTINUE; + } + + qemu_put_be64(f, offset); size = 8; - if (!cont) { + if (block != last_sent_block) { qemu_put_byte(f, strlen(block->idstr)); qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr)); size += 1 + strlen(block->idstr); + last_sent_block = block; } return size; } -/* This is the last block that we have visited serching for dirty pages - */ -static RAMBlock *last_seen_block; -/* This is the last block from where we have sent data */ -static RAMBlock *last_sent_block; -static ram_addr_t last_offset; -static unsigned long *migration_bitmap; -static uint64_t migration_dirty_pages; -static uint32_t last_version; -static bool ram_bulk_stage; - /* 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. @@ -353,11 +369,27 @@ static void xbzrle_cache_zero_page(ram_addr_t current_addr) #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, int cont, bool last_stage) + ram_addr_t offset, bool last_stage, + uint64_t *bytes_transferred) { - int encoded_len = 0, bytes_sent = -1; + int encoded_len = 0, bytes_xbzrle; uint8_t *prev_cached_page; if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) { @@ -404,15 +436,16 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data, } /* Send XBZRLE based compressed page */ - bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_XBZRLE); + 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_sent += encoded_len + 1 + 2; + bytes_xbzrle += encoded_len + 1 + 2; acct_info.xbzrle_pages++; - acct_info.xbzrle_bytes += bytes_sent; + acct_info.xbzrle_bytes += bytes_xbzrle; + *bytes_transferred += bytes_xbzrle; - return bytes_sent; + return 1; } static inline @@ -575,55 +608,64 @@ static void migration_bitmap_sync(void) } } -/* +/** * ram_save_page: Send the given page to the stream * - * Returns: Number of bytes written. + * 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) + bool last_stage, uint64_t *bytes_transferred) { - int bytes_sent; - int cont; + int pages = -1; + uint64_t bytes_xmit; ram_addr_t current_addr; MemoryRegion *mr = block->mr; uint8_t *p; int ret; bool send_async = true; - cont = (block == last_sent_block) ? RAM_SAVE_FLAG_CONTINUE : 0; - p = memory_region_get_ram_ptr(mr) + offset; /* In doubt sent page as normal */ - bytes_sent = -1; + bytes_xmit = 0; ret = ram_control_save_page(f, block->offset, - offset, TARGET_PAGE_SIZE, &bytes_sent); + offset, TARGET_PAGE_SIZE, &bytes_xmit); + if (bytes_xmit) { + *bytes_transferred += bytes_xmit; + pages = 1; + } XBZRLE_cache_lock(); current_addr = block->offset + offset; if (ret != RAM_SAVE_CONTROL_NOT_SUPP) { if (ret != RAM_SAVE_CONTROL_DELAYED) { - if (bytes_sent > 0) { + if (bytes_xmit > 0) { acct_info.norm_pages++; - } else if (bytes_sent == 0) { + } else if (bytes_xmit == 0) { acct_info.dup_pages++; } } } else if (is_zero_range(p, TARGET_PAGE_SIZE)) { acct_info.dup_pages++; - bytes_sent = save_block_hdr(f, block, offset, cont, - RAM_SAVE_FLAG_COMPRESS); + *bytes_transferred += save_page_header(f, block, + offset | RAM_SAVE_FLAG_COMPRESS); qemu_put_byte(f, 0); - bytes_sent++; + *bytes_transferred += 1; + pages = 1; /* Must let xbzrle know, otherwise a previous (now 0'd) cached * page would be stale */ xbzrle_cache_zero_page(current_addr); } else if (!ram_bulk_stage && migrate_use_xbzrle()) { - bytes_sent = save_xbzrle_page(f, &p, current_addr, block, - offset, cont, last_stage); + 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 @@ -633,37 +675,44 @@ static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset, } /* XBZRLE overflow or normal page */ - if (bytes_sent == -1) { - bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_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_sent += TARGET_PAGE_SIZE; + *bytes_transferred += TARGET_PAGE_SIZE; + pages = 1; acct_info.norm_pages++; } XBZRLE_cache_unlock(); - return bytes_sent; + return pages; } -/* - * ram_find_and_save_block: Finds a page to send and sends it to f +/** + * ram_find_and_save_block: Finds a dirty page and sends it to f * * Called within an RCU critical section. * - * Returns: The number of bytes written. + * 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) +static int ram_find_and_save_block(QEMUFile *f, bool last_stage, + uint64_t *bytes_transferred) { RAMBlock *block = last_seen_block; ram_addr_t offset = last_offset; bool complete_round = false; - int bytes_sent = 0; + int pages = 0; MemoryRegion *mr; if (!block) @@ -685,11 +734,11 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage) ram_bulk_stage = false; } } else { - bytes_sent = ram_save_page(f, block, offset, last_stage); + pages = ram_save_page(f, block, offset, last_stage, + bytes_transferred); /* if page is unmodified, continue to the next */ - if (bytes_sent > 0) { - last_sent_block = block; + if (pages > 0) { break; } } @@ -697,7 +746,8 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage) last_seen_block = block; last_offset = offset; - return bytes_sent; + + return pages; } static uint64_t bytes_transferred; @@ -881,7 +931,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) int ret; int i; int64_t t0; - int total_sent = 0; + int pages_sent = 0; rcu_read_lock(); if (ram_list.version != last_version) { @@ -896,14 +946,14 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); i = 0; while ((ret = qemu_file_rate_limit(f)) == 0) { - int bytes_sent; + int pages; - bytes_sent = ram_find_and_save_block(f, false); - /* no more blocks to sent */ - if (bytes_sent == 0) { + pages = ram_find_and_save_block(f, false, &bytes_transferred); + /* no more pages to sent */ + if (pages == 0) { break; } - total_sent += bytes_sent; + pages_sent += pages; acct_info.iterations++; check_guest_throttling(); /* we want to check in the 1st loop, just in case it was the 1st time @@ -929,12 +979,6 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) */ ram_control_after_iterate(f, RAM_CONTROL_ROUND); - bytes_transferred += total_sent; - - /* - * Do not count these 8 bytes into total_sent, so that we can - * return 0 if no page had been dirtied. - */ qemu_put_be64(f, RAM_SAVE_FLAG_EOS); bytes_transferred += 8; @@ -943,7 +987,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) return ret; } - return total_sent; + return pages_sent; } /* Called with iothread lock */ @@ -959,14 +1003,13 @@ static int ram_save_complete(QEMUFile *f, void *opaque) /* flush all remaining blocks regardless of rate limiting */ while (true) { - int bytes_sent; + int pages; - bytes_sent = ram_find_and_save_block(f, true); + pages = ram_find_and_save_block(f, true, &bytes_transferred); /* no more blocks to sent */ - if (bytes_sent == 0) { + if (pages == 0) { break; } - bytes_transferred += bytes_sent; } ram_control_after_iterate(f, RAM_CONTROL_FINISH); |