docs tests: Fix use of migrate_set_parameter

docs/multi-thread-compression.txt uses parameter names with
underscores instead of dashes.  Wrong since day one.

docs/rdma.txt, tests/qemu-iotests/181, and tests/qtest/test-hmp.c are
wrong the same way since commit cbde7be900d2 (v6.0.0).  Hard to see,
as test-hmp doesn't check whether the commands work, and iotest 181
appears to be unaffected.

Fixes: 263170e679df (docs: Add a doc about multiple thread compression)
Fixes: cbde7be900d2 (migrate: remove QMP/HMP commands for speed, downtime and cache size)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

docs/multi-thread-compression.txt

@@ -117,13 +117,13 @@ to support the multiple thread compression migration:
     {qemu} migrate_set_capability compress on
 
 3. Set the compression thread count on source:
-    {qemu} migrate_set_parameter compress_threads 12
+    {qemu} migrate_set_parameter compress-threads 12
 
 4. Set the compression level on the source:
-    {qemu} migrate_set_parameter compress_level 1
+    {qemu} migrate_set_parameter compress-level 1
 
 5. Set the decompression thread count on destination:
-    {qemu} migrate_set_parameter decompress_threads 3
+    {qemu} migrate_set_parameter decompress-threads 3
 
 6. Start outgoing migration:
     {qemu} migrate -d tcp:destination.host:4444
@@ -133,9 +133,9 @@ to support the multiple thread compression migration:
 
 The following are the default settings:
     compress: off
-    compress_threads: 8
-    decompress_threads: 2
-    compress_level: 1 (which means best speed)
+    compress-threads: 8
+    decompress-threads: 2
+    compress-level: 1 (which means best speed)
 
 So, only the first two steps are required to use the multiple
 thread compression in migration. You can do more if the default

docs/rdma.txt

@@ -89,7 +89,7 @@ RUNNING:
 First, set the migration speed to match your hardware's capabilities:
 
 QEMU Monitor Command:
-$ migrate_set_parameter max_bandwidth 40g # or whatever is the MAX of your RDMA device
+$ migrate_set_parameter max-bandwidth 40g # or whatever is the MAX of your RDMA device
 
 Next, on the destination machine, add the following to the QEMU command line:
 

tests/qemu-iotests/181

@@ -109,7 +109,7 @@ if [ ${QEMU_STATUS[$dest]} -lt 0 ]; then
     _notrun 'Postcopy is not supported'
 fi
 
-_send_qemu_cmd $src 'migrate_set_parameter max_bandwidth 4k' "(qemu)"
+_send_qemu_cmd $src 'migrate_set_parameter max-bandwidth 4k' "(qemu)"
 _send_qemu_cmd $src 'migrate_set_capability postcopy-ram on' "(qemu)"
 _send_qemu_cmd $src "migrate -d unix:${MIG_SOCKET}" "(qemu)"
 _send_qemu_cmd $src 'migrate_start_postcopy' "(qemu)"

tests/qtest/test-hmp.c

@@ -45,9 +45,9 @@ static const char *hmp_cmds[] = {
     "log all",
     "log none",
     "memsave 0 4096 \"/dev/null\"",
-    "migrate_set_parameter xbzrle_cache_size 1",
-    "migrate_set_parameter downtime_limit 1",
-    "migrate_set_parameter max_bandwidth 1",
+    "migrate_set_parameter xbzrle-cache-size 1",
+    "migrate_set_parameter downtime-limit 1",
+    "migrate_set_parameter max-bandwidth 1",
     "netdev_add user,id=net1",
     "set_link net1 off",
     "set_link net1 on",