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-rw-r--r--Makefile.objs2
-rw-r--r--savevm.c159
-rw-r--r--xbzrle.c173
3 files changed, 174 insertions, 160 deletions
diff --git a/Makefile.objs b/Makefile.objs
index 68eb0cef1a..21e9c911f5 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -59,7 +59,7 @@ common-obj-$(CONFIG_LINUX) += fsdev/
common-obj-y += migration.o migration-tcp.o
common-obj-y += qemu-char.o #aio.o
common-obj-y += block-migration.o
-common-obj-y += page_cache.o
+common-obj-y += page_cache.o xbzrle.o
common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
diff --git a/savevm.c b/savevm.c
index 304d1effe5..b947e6a303 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2388,162 +2388,3 @@ 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 = (long)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;
-}
diff --git a/xbzrle.c b/xbzrle.c
new file mode 100644
index 0000000000..fbcb35d0e3
--- /dev/null
+++ b/xbzrle.c
@@ -0,0 +1,173 @@
+/*
+ * Xor Based Zero Run Length Encoding
+ *
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ * Orit Wasserman <owasserm@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#include "qemu-common.h"
+#include "include/migration/migration.h"
+
+/*
+ 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 = (long)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;
+}
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