Re: [libvirt] [PATCH v2 10/15] qemu: capabilities: Add support for QMP schema introspection

Allow detecting capabilities according to the qemu QMP schema. This is necessary as sometimes the availability of certain options depends on the presence of a field in the schema. This patch adds support for loading the QMP schema when detecting qemu capabilities and adds a very simple query language to allow traversing the schema and selecting a certain element from it. The infrastructure in this patch uses a query path to set a specific capability flag according to the availability of the given element in the schema. --- Notes: v2: - fixed typos - added docs for one of the helper functions and changed param order - added hint for query string format docs src/qemu/qemu_capabilities.c | 191 ++++++++++++++++++++++ src/qemu/qemu_capabilities.h | 1 + tests/qemucapabilitiesdata/caps_2.5.0.x86_64.xml | 1 + tests/qemucapabilitiesdata/caps_2.6.0.ppc64le.xml | 1 + tests/qemucapabilitiesdata/caps_2.6.0.x86_64.xml | 1 + tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml | 1 + 6 files changed, 196 insertions(+) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 7a8202a..56c9deb 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -347,6 +347,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST, "machine-iommu", "virtio-vga", "drive-iotune-max-length", + "query-qmp-schema", ); @@ -1488,6 +1489,7 @@ struct virQEMUCapsStringFlags virQEMUCapsCommands[] = { { "rtc-reset-reinjection", QEMU_CAPS_RTC_RESET_REINJECTION }, { "migrate-incoming", QEMU_CAPS_INCOMING_DEFER }, { "query-hotpluggable-cpus", QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS }, + { "query-qmp-schema", QEMU_CAPS_QUERY_QMP_SCHEMA } }; struct virQEMUCapsStringFlags virQEMUCapsMigration[] = { @@ -1692,6 +1694,11 @@ static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsUSBNECXHCI[] = { { "p3", QEMU_CAPS_NEC_USB_XHCI_PORTS }, }; +/* see documentation for virQEMUCapsQMPSchemaGetByPath for the query format */ +static struct virQEMUCapsStringFlags virQEMUCapsQMPSchemaQueries[] = { + { "bogus/path/to/satisfy/compiler", 0 }, +}; + struct virQEMUCapsObjectTypeProps { const char *type; struct virQEMUCapsStringFlags *props; @@ -3696,6 +3703,187 @@ virQEMUCapsInitArchQMPBasic(virQEMUCapsPtr qemuCaps, return ret; } + +/** + * virQEMUCapsQMPSchemaObjectGetType: + * @field: name of the object containing the requested type + * @name: name of the requested type + * @namefield: name of the object property holding @name + * + * Helper that selects the type of a QMP schema object or it's variant. Returns

+ * the type string on success or NULL on error.