diff options
Diffstat (limited to 'dump.c')
| -rw-r--r-- | dump.c | 231 |
1 files changed, 231 insertions, 0 deletions
@@ -25,6 +25,14 @@ #include "qapi/error.h" #include "qmp-commands.h" +#include <zlib.h> +#ifdef CONFIG_LZO +#include <lzo/lzo1x.h> +#endif +#ifdef CONFIG_SNAPPY +#include <snappy-c.h> +#endif + static uint16_t cpu_convert_to_target16(uint16_t val, int endian) { if (endian == ELFDATA2LSB) { @@ -1212,6 +1220,229 @@ static void free_data_cache(DataCache *data_cache) g_free(data_cache->buf); } +static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress) +{ + size_t len_buf_out_zlib, len_buf_out_lzo, len_buf_out_snappy; + size_t len_buf_out; + + /* init buf_out */ + len_buf_out_zlib = len_buf_out_lzo = len_buf_out_snappy = 0; + + /* buf size for zlib */ + len_buf_out_zlib = compressBound(page_size); + + /* buf size for lzo */ +#ifdef CONFIG_LZO + if (flag_compress & DUMP_DH_COMPRESSED_LZO) { + if (lzo_init() != LZO_E_OK) { + /* return 0 to indicate lzo is unavailable */ + return 0; + } + } + + /* + * LZO will expand incompressible data by a little amount. please check the + * following URL to see the expansion calculation: + * http://www.oberhumer.com/opensource/lzo/lzofaq.php + */ + len_buf_out_lzo = page_size + page_size / 16 + 64 + 3; +#endif + +#ifdef CONFIG_SNAPPY + /* buf size for snappy */ + len_buf_out_snappy = snappy_max_compressed_length(page_size); +#endif + + /* get the biggest that can store all kinds of compressed page */ + len_buf_out = MAX(len_buf_out_zlib, + MAX(len_buf_out_lzo, len_buf_out_snappy)); + + return len_buf_out; +} + +/* + * check if the page is all 0 + */ +static inline bool is_zero_page(const uint8_t *buf, size_t page_size) +{ + return buffer_is_zero(buf, page_size); +} + +static int write_dump_pages(DumpState *s) +{ + int ret = 0; + DataCache page_desc, page_data; + size_t len_buf_out, size_out; +#ifdef CONFIG_LZO + lzo_bytep wrkmem = NULL; +#endif + uint8_t *buf_out = NULL; + off_t offset_desc, offset_data; + PageDescriptor pd, pd_zero; + uint8_t *buf; + int endian = s->dump_info.d_endian; + GuestPhysBlock *block_iter = NULL; + uint64_t pfn_iter; + + /* get offset of page_desc and page_data in dump file */ + offset_desc = s->offset_page; + offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable; + + prepare_data_cache(&page_desc, s, offset_desc); + prepare_data_cache(&page_data, s, offset_data); + + /* prepare buffer to store compressed data */ + len_buf_out = get_len_buf_out(s->page_size, s->flag_compress); + if (len_buf_out == 0) { + dump_error(s, "dump: failed to get length of output buffer.\n"); + goto out; + } + +#ifdef CONFIG_LZO + wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS); +#endif + + buf_out = g_malloc(len_buf_out); + + /* + * init zero page's page_desc and page_data, because every zero page + * uses the same page_data + */ + pd_zero.size = cpu_convert_to_target32(s->page_size, endian); + pd_zero.flags = cpu_convert_to_target32(0, endian); + pd_zero.offset = cpu_convert_to_target64(offset_data, endian); + pd_zero.page_flags = cpu_convert_to_target64(0, endian); + buf = g_malloc0(s->page_size); + ret = write_cache(&page_data, buf, s->page_size, false); + g_free(buf); + if (ret < 0) { + dump_error(s, "dump: failed to write page data(zero page).\n"); + goto out; + } + + offset_data += s->page_size; + + /* + * dump memory to vmcore page by page. zero page will all be resided in the + * first page of page section + */ + while (get_next_page(&block_iter, &pfn_iter, &buf, s)) { + /* check zero page */ + if (is_zero_page(buf, s->page_size)) { + ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor), + false); + if (ret < 0) { + dump_error(s, "dump: failed to write page desc.\n"); + goto out; + } + } else { + /* + * not zero page, then: + * 1. compress the page + * 2. write the compressed page into the cache of page_data + * 3. get page desc of the compressed page and write it into the + * cache of page_desc + * + * only one compression format will be used here, for + * s->flag_compress is set. But when compression fails to work, + * we fall back to save in plaintext. + */ + size_out = len_buf_out; + if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) && + (compress2(buf_out, (uLongf *)&size_out, buf, s->page_size, + Z_BEST_SPEED) == Z_OK) && (size_out < s->page_size)) { + pd.flags = cpu_convert_to_target32(DUMP_DH_COMPRESSED_ZLIB, + endian); + pd.size = cpu_convert_to_target32(size_out, endian); + + ret = write_cache(&page_data, buf_out, size_out, false); + if (ret < 0) { + dump_error(s, "dump: failed to write page data.\n"); + goto out; + } +#ifdef CONFIG_LZO + } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) && + (lzo1x_1_compress(buf, s->page_size, buf_out, + (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) && + (size_out < s->page_size)) { + pd.flags = cpu_convert_to_target32(DUMP_DH_COMPRESSED_LZO, + endian); + pd.size = cpu_convert_to_target32(size_out, endian); + + ret = write_cache(&page_data, buf_out, size_out, false); + if (ret < 0) { + dump_error(s, "dump: failed to write page data.\n"); + goto out; + } +#endif +#ifdef CONFIG_SNAPPY + } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) && + (snappy_compress((char *)buf, s->page_size, + (char *)buf_out, &size_out) == SNAPPY_OK) && + (size_out < s->page_size)) { + pd.flags = cpu_convert_to_target32( + DUMP_DH_COMPRESSED_SNAPPY, endian); + pd.size = cpu_convert_to_target32(size_out, endian); + + ret = write_cache(&page_data, buf_out, size_out, false); + if (ret < 0) { + dump_error(s, "dump: failed to write page data.\n"); + goto out; + } +#endif + } else { + /* + * fall back to save in plaintext, size_out should be + * assigned to s->page_size + */ + pd.flags = cpu_convert_to_target32(0, endian); + size_out = s->page_size; + pd.size = cpu_convert_to_target32(size_out, endian); + + ret = write_cache(&page_data, buf, s->page_size, false); + if (ret < 0) { + dump_error(s, "dump: failed to write page data.\n"); + goto out; + } + } + + /* get and write page desc here */ + pd.page_flags = cpu_convert_to_target64(0, endian); + pd.offset = cpu_convert_to_target64(offset_data, endian); + offset_data += size_out; + + ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false); + if (ret < 0) { + dump_error(s, "dump: failed to write page desc.\n"); + goto out; + } + } + } + + ret = write_cache(&page_desc, NULL, 0, true); + if (ret < 0) { + dump_error(s, "dump: failed to sync cache for page_desc.\n"); + goto out; + } + ret = write_cache(&page_data, NULL, 0, true); + if (ret < 0) { + dump_error(s, "dump: failed to sync cache for page_data.\n"); + goto out; + } + +out: + free_data_cache(&page_desc); + free_data_cache(&page_data); + +#ifdef CONFIG_LZO + g_free(wrkmem); +#endif + + g_free(buf_out); + + return ret; +} + static ram_addr_t get_start_block(DumpState *s) { GuestPhysBlock *block; |