| Message ID | be94d24847d38cb5a1172ed22d0f86e7c0ec8562.1570705279.git.pkrempa@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | qapi: Add detection for the 'savevm' fix for blockdev | expand |
Peter Krempa <pkrempa@redhat.com> writes: > 'savevm' was buggy as it considered all monitor-owned block device nodes > for snapshot. With introduction of -blockdev the common usage made all > nodes including protocol and backing file nodes monitor-owned and thus > considered for snapshot. > > This is a problem since the 'file' protocol nodes can't have internal > snapshots and it does not make sense to take snapshot of nodes > representing backing files. > > This was fixed by commit 05f4aced658a02b02 clients need to be able to > detect whether this fix is present. 05f4aced658a02b02. Clients > > Since savevm does not have an QMP alternative, add the feature for the > 'human-monitor-command' backdoor which is used to call this command in > modern use. > > Signed-off-by: Peter Krempa <pkrempa@redhat.com> Preferrably with the commit message tweak: Reviewed-by: Markus Armbruster <armbru@redhat.com>
On 10/10/19 6:05 AM, Peter Krempa wrote: In addition to Markus' review, > 'savevm' was buggy as it considered all monitor-owned block device nodes > for snapshot. With introduction of -blockdev the common usage made all With the introduction of -blockdev, the common usage > nodes including protocol and backing file nodes monitor-owned and thus nodes be monitor-owned > considered for snapshot. > > This is a problem since the 'file' protocol nodes can't have internal > snapshots and it does not make sense to take snapshot of nodes > representing backing files. > > This was fixed by commit 05f4aced658a02b02 clients need to be able to > detect whether this fix is present. > > Since savevm does not have an QMP alternative, add the feature for the > 'human-monitor-command' backdoor which is used to call this command in > modern use. > > Signed-off-by: Peter Krempa <pkrempa@redhat.com> > --- > qapi/misc.json | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/qapi/misc.json b/qapi/misc.json > index 6bd11f50e6..5d0070aa43 100644 > --- a/qapi/misc.json > +++ b/qapi/misc.json > @@ -1020,6 +1020,12 @@ > # > # @cpu-index: The CPU to use for commands that require an implicit CPU > # > +# Features: > +# @savevm-blockdev-monitor-nodes: If present, the HMP command savevm only > +# snapshots monitor-owned nodes if they have no > +# parents. This allows to use 'savevm' with > +# -blockdev. (since 4.2) s/to use/the use of/ > +# > # Returns: the output of the command as a string > # > # Since: 0.14.0 > @@ -1047,7 +1053,8 @@ > ## > { 'command': 'human-monitor-command', > 'data': {'command-line': 'str', '*cpu-index': 'int'}, > - 'returns': 'str' } > + 'returns': 'str', > + 'features': [ 'savevm-blockdev-monitor-nodes' ] } > > ## > # @change: >
diff --git a/qapi/misc.json b/qapi/misc.json index 6bd11f50e6..5d0070aa43 100644 --- a/qapi/misc.json +++ b/qapi/misc.json @@ -1020,6 +1020,12 @@ # # @cpu-index: The CPU to use for commands that require an implicit CPU # +# Features: +# @savevm-blockdev-monitor-nodes: If present, the HMP command savevm only +# snapshots monitor-owned nodes if they have no +# parents. This allows to use 'savevm' with +# -blockdev. (since 4.2) +# # Returns: the output of the command as a string # # Since: 0.14.0 @@ -1047,7 +1053,8 @@ ## { 'command': 'human-monitor-command', 'data': {'command-line': 'str', '*cpu-index': 'int'}, - 'returns': 'str' } + 'returns': 'str', + 'features': [ 'savevm-blockdev-monitor-nodes' ] } ## # @change:
'savevm' was buggy as it considered all monitor-owned block device nodes for snapshot. With introduction of -blockdev the common usage made all nodes including protocol and backing file nodes monitor-owned and thus considered for snapshot. This is a problem since the 'file' protocol nodes can't have internal snapshots and it does not make sense to take snapshot of nodes representing backing files. This was fixed by commit 05f4aced658a02b02 clients need to be able to detect whether this fix is present. Since savevm does not have an QMP alternative, add the feature for the 'human-monitor-command' backdoor which is used to call this command in modern use. Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- qapi/misc.json | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)