Kevin Wolf <kw...@redhat.com> writes:
> auto-read-only=on changed its behaviour in file-posix for the 4.0
> release.
Commit hash, please.
> This change cannot be detected through the usual mechanisms
> like schema introspection. Add a new feature to query-qemu-features to
> allow libvirt to detect the presence of the new behaviour.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> ---
> qapi/misc.json | 7 ++++++-
> qmp.c | 1 +
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/qapi/misc.json b/qapi/misc.json
> index d892f37633..df23c54a65 100644
> --- a/qapi/misc.json
> +++ b/qapi/misc.json
> @@ -3058,10 +3058,15 @@
> # Information about support for QEMU features that isn't available through
> # schema introspection.
> #
> +# @file-posix-dynamic-auto-read-only:
> +# true if auto-read-only=on means that the image file is dynamically
> reopened
> +# read-only or read-write depending on whether any writers are attached to
> +# the node.
> +#
The name @file-posix-dynamic-auto-read-only suggests the semantic change
of auto-read-only=on explained in the doc comment applies only to some
BlockDrivers (as a non-variant member of BlockdevOptions, auto-read-only
applies to all). Which ones exactly?
> # Since: 4.0
> ##
> { 'struct': 'QemuFeatures',
> - 'data': { } }
> + 'data': { 'file-posix-dynamic-auto-read-only': 'bool' } }
>
> ##
> # @query-qemu-features:
> diff --git a/qmp.c b/qmp.c
> index 0aad533eca..2a887c1e7d 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -723,6 +723,7 @@ QemuFeatures *qmp_query_qemu_features(Error **errp)
> QemuFeatures *caps = g_new(QemuFeatures, 1);
>
> *caps = (QemuFeatures) {
> + .file_posix_dynamic_auto_read_only = true,
> };
>
> return caps;
Running the command provides no additional information over schema
introspection. Kind of contradicts "Information about support for QEMU
features that isn't available through schema introspection" :)
