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author | Anthony Liguori <aliguori@us.ibm.com> | 2012-08-13 16:02:11 -0500 |
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committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-08-13 16:02:11 -0500 |
commit | ac839ccd8c30fe5706cc43f00e056049d6e55377 (patch) | |
tree | d2e37ee8bd7750ce1dd01c4dd6cec21a87551682 /savevm.c | |
parent | 6a1f9d0c1fbf186d3d68cb2af43d047637c93072 (diff) | |
parent | dd051c7217eae04191169ac62f6ffb7531c8da32 (diff) | |
download | hqemu-ac839ccd8c30fe5706cc43f00e056049d6e55377.zip hqemu-ac839ccd8c30fe5706cc43f00e056049d6e55377.tar.gz |
Merge remote-tracking branch 'quintela/migration-next-20120808' into staging
* quintela/migration-next-20120808:
Restart optimization on stage3 update version
Add XBZRLE statistics
Add migration accounting for normal and duplicate pages
Change total_time to total-time in MigrationStats
Add migrate_set_cache_size command
Add XBZRLE to ram_save_block and ram_save_live
Add xbzrle_encode_buffer and xbzrle_decode_buffer functions
Add uleb encoding/decoding functions
Add cache handling functions
Add XBZRLE documentation
Add migrate-set-capabilities
Add migration capabilities
Diffstat (limited to 'savevm.c')
-rw-r--r-- | savevm.c | 159 |
1 files changed, 159 insertions, 0 deletions
@@ -2392,3 +2392,162 @@ void vmstate_register_ram_global(MemoryRegion *mr) { vmstate_register_ram(mr, NULL); } + +/* + page = zrun nzrun + | zrun nzrun page + + zrun = length + + nzrun = length byte... + + length = uleb128 encoded integer + */ +int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen, + uint8_t *dst, int dlen) +{ + uint32_t zrun_len = 0, nzrun_len = 0; + int d = 0, i = 0; + long res, xor; + uint8_t *nzrun_start = NULL; + + g_assert(!(((uintptr_t)old_buf | (uintptr_t)new_buf | slen) % + sizeof(long))); + + while (i < slen) { + /* overflow */ + if (d + 2 > dlen) { + return -1; + } + + /* not aligned to sizeof(long) */ + res = (slen - i) % sizeof(long); + while (res && old_buf[i] == new_buf[i]) { + zrun_len++; + i++; + res--; + } + + /* word at a time for speed */ + if (!res) { + while (i < slen && + (*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) { + i += sizeof(long); + zrun_len += sizeof(long); + } + + /* go over the rest */ + while (i < slen && old_buf[i] == new_buf[i]) { + zrun_len++; + i++; + } + } + + /* buffer unchanged */ + if (zrun_len == slen) { + return 0; + } + + /* skip last zero run */ + if (i == slen) { + return d; + } + + d += uleb128_encode_small(dst + d, zrun_len); + + zrun_len = 0; + nzrun_start = new_buf + i; + + /* overflow */ + if (d + 2 > dlen) { + return -1; + } + /* not aligned to sizeof(long) */ + res = (slen - i) % sizeof(long); + while (res && old_buf[i] != new_buf[i]) { + i++; + nzrun_len++; + res--; + } + + /* word at a time for speed, use of 32-bit long okay */ + if (!res) { + /* truncation to 32-bit long okay */ + long mask = 0x0101010101010101ULL; + while (i < slen) { + xor = *(long *)(old_buf + i) ^ *(long *)(new_buf + i); + if ((xor - mask) & ~xor & (mask << 7)) { + /* found the end of an nzrun within the current long */ + while (old_buf[i] != new_buf[i]) { + nzrun_len++; + i++; + } + break; + } else { + i += sizeof(long); + nzrun_len += sizeof(long); + } + } + } + + d += uleb128_encode_small(dst + d, nzrun_len); + /* overflow */ + if (d + nzrun_len > dlen) { + return -1; + } + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + nzrun_len = 0; + } + + return d; +} + +int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen) +{ + int i = 0, d = 0; + int ret; + uint32_t count = 0; + + while (i < slen) { + + /* zrun */ + if ((slen - i) < 2) { + return -1; + } + + ret = uleb128_decode_small(src + i, &count); + if (ret < 0 || (i && !count)) { + return -1; + } + i += ret; + d += count; + + /* overflow */ + if (d > dlen) { + return -1; + } + + /* nzrun */ + if ((slen - i) < 2) { + return -1; + } + + ret = uleb128_decode_small(src + i, &count); + if (ret < 0 || !count) { + return -1; + } + i += ret; + + /* overflow */ + if (d + count > dlen || i + count > slen) { + return -1; + } + + memcpy(dst + d, src + i, count); + d += count; + i += count; + } + + return d; +} |