On 06/13/2018 10:47 AM, Denis Plotnikov wrote:
The command enables/disables copy-on-read mode for VM's disk while
VM is running.
This is needed when using external disk readers to shape access pattern
to the disk backend.
Signed-off-by: Denis Plotnikov <dplotni...@virtuozzo.com>
---
Deferring thoughts on the actual design for later; this is just a
cursory implementation review for now.
+++ b/qapi/block-core.json
@@ -4701,6 +4701,26 @@
{ 'command': 'block-set-write-threshold',
'data': { 'node-name': 'str', 'write-threshold': 'uint64' } }
+##
+# @block-set-copy-on-read:
+#
+# Enables and disables the copy-on-read property of a block device.
+#
+# @device: device or graph node name on which copy-on-read must be set.
+#
+# Since: 2.12
We've missed the 2.12 release. This should be since 3.0.
+#
+# Example:
+#
+# -> { "execute": "block-set-copy-on-read",
+# "arguments": { "device": "scsi0-0-0-0",
+# "enable": true } }
+# <- { "return": {} }
+#
+##
+{ 'command': 'block-set-copy-on-read',
+ 'data': { 'device': 'str', 'enable': 'bool' } }
Missing documentation of @enable.
And just checking: is the current copy-on-read setting visible through
an existing query-* command, or have you just introduced a write-only
toggle? If the state can be changed at runtime, then it needs to be
easy to learn what the current state is.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
