Merge remote-tracking branch 'quintela/migration.next' into staging

# By Orit Wasserman
# Via Juan Quintela
* quintela/migration.next:
  Fix error message in migrate_set_capability HMP command
  Allow XBZRLE decoding without enabling the capability
  Fix example for query-migrate-capabilities
  Add XBZRLE testing
  Move XBZRLE encoding code to a separate file to allow testing

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
 

arch_init.c

@@ -851,9 +851,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 
             qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
         } else if (flags & RAM_SAVE_FLAG_XBZRLE) {
-            if (!migrate_use_xbzrle()) {
-                return -EINVAL;
-            }
             void *host = host_from_stream_offset(f, addr, flags);
             if (!host) {
                 return -EINVAL;

hmp.c

@@ -892,7 +892,7 @@ void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict)
     qapi_free_MigrationCapabilityStatusList(caps);
 
     if (err) {
-        monitor_printf(mon, "migrate_set_parameter: %s\n",
+        monitor_printf(mon, "migrate_set_capability: %s\n",
                        error_get_pretty(err));
         error_free(err);
     }

qmp-commands.hx

@@ -2601,10 +2601,8 @@ Arguments:
 Example:
 
 -> { "execute": "query-migrate-capabilities" }
-<- { "return": {
-        "capabilities" :  [ { "capability" : "xbzrle", "state" : false } ]
-     }
-   }
+<- { "return": [ { "state": false, "capability": "xbzrle" } ] }
+
 EQMP
 
     {

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;
-}

tests/Makefile

@@ -50,6 +50,8 @@ check-unit-y += tests/test-hbitmap$(EXESUF)
 check-unit-y += tests/test-x86-cpuid$(EXESUF)
 # all code tested by test-x86-cpuid is inside topology.h
 gcov-files-test-x86-cpuid-y =
+check-unit-y += tests/test-xbzrle$(EXESUF)
+gcov-files-test-xbzrle-y = xbzrle.c
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -98,6 +100,7 @@ tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(block-obj-y) libqemu
 tests/test-iov$(EXESUF): tests/test-iov.o libqemuutil.a
 tests/test-hbitmap$(EXESUF): tests/test-hbitmap.o libqemuutil.a libqemustub.a
 tests/test-x86-cpuid$(EXESUF): tests/test-x86-cpuid.o
+tests/test-xbzrle$(EXESUF): tests/test-xbzrle.o xbzrle.o page_cache.o libqemuutil.a
 
 tests/test-qapi-types.c tests/test-qapi-types.h :\
 $(SRC_PATH)/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py