Introduce EXPAND_CPU_FEATURES flag for domain capabilities

The new VIR_CONNECT_GET_DOMAIN_CAPABILITIES_EXPAND_CPU_FEATURES flag for
virConnectGetDomainCapabilities can be used to request the host-model
CPU definition to include all supported features (normally only extra
features relative to the selected CPU model are listed).

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

include/libvirt/libvirt-domain.h

@@ -1517,6 +1517,8 @@ int virDomainMigrateStartPostCopy(virDomainPtr domain,
 typedef enum {
     /* Report host model with deprecated features disabled. (Since: 11.0.0) */
     VIR_CONNECT_GET_DOMAIN_CAPABILITIES_DISABLE_DEPRECATED_FEATURES = (1 << 0),
+    /* Report all host model CPU features. (Since: 12.2.0) */
+    VIR_CONNECT_GET_DOMAIN_CAPABILITIES_EXPAND_CPU_FEATURES = (1 << 1),
 } virConnectGetDomainCapabilitiesFlags;
 
 char * virConnectGetDomainCapabilities(virConnectPtr conn,

src/libvirt-domain.c

@@ -12330,6 +12330,11 @@ virDomainSetUserPassword(virDomainPtr dom,
  * instance, if host, libvirt and qemu is capable of VFIO
  * passthrough and so on.
  *
+ * If @flags includes VIR_CONNECT_GET_DOMAIN_CAPABILITIES_EXPAND_CPU_FEATURES,
+ * libvirt will explicitly list all CPU features (in host-model CPU definition)
+ * that are supported on the host. Without this flag features that are part of
+ * the CPU model itself will not be listed.
+ *
  * Returns NULL in case of error or an XML string
  * defining the capabilities.
  *