src: define virDomainGetMessages API

This API allows fetching a list of informational messages recorded
against the domain. This provides a way to give information about
tainting of the guest due to undesirable actions/configs, as well
as provide details of deprecated features.

The output of this API is explicitly targetted at humans, not
machines, so it is inappropriate to attempt to pattern match on
the strings and take action off them, not least because the messages
are marked for translation.

Should there be a demand for machine targetted information, this
would have to be addressed via a new API, and is not planned at
this point in time.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

include/libvirt/libvirt-domain.h

@@ -5119,4 +5119,13 @@ int virDomainAuthorizedSSHKeysSet(virDomainPtr domain,
                                   unsigned int nkeys,
                                   unsigned int flags);
 
+typedef enum {
+    VIR_DOMAIN_MESSAGE_DEPRECATION = (1 << 0),
+    VIR_DOMAIN_MESSAGE_TAINTING = (1 << 1),
+} virDomainMessageType;
+
+int virDomainGetMessages(virDomainPtr domain,
+                         char ***msgs,
+                         unsigned int flags);
+
 #endif /* LIBVIRT_DOMAIN_H */

src/driver-hypervisor.h

@@ -1400,6 +1400,11 @@ typedef int
                                     unsigned int nkeys,
                                     unsigned int flags);
 
+typedef int
+(*virDrvDomainGetMessages)(virDomainPtr domain,
+                           char ***msgs,
+                           unsigned int flags);
+
 typedef struct _virHypervisorDriver virHypervisorDriver;
 typedef virHypervisorDriver *virHypervisorDriverPtr;
 
@@ -1665,4 +1670,5 @@ struct _virHypervisorDriver {
     virDrvDomainBackupGetXMLDesc domainBackupGetXMLDesc;
     virDrvDomainAuthorizedSSHKeysGet domainAuthorizedSSHKeysGet;
     virDrvDomainAuthorizedSSHKeysSet domainAuthorizedSSHKeysSet;
+    virDrvDomainGetMessages domainGetMessages;
 };

src/libvirt-domain.c

@@ -13102,3 +13102,57 @@ virDomainAuthorizedSSHKeysSet(virDomainPtr domain,
     virDispatchError(conn);
     return -1;
 }
+
+
+/**
+ * virDomainGetMessages:
+ * @domain: a domain object
+ * @msgs: pointer to a variable to store messages
+ * @flags: zero or more virDomainMessageType flags
+ *
+ * Fetch a list of all messages recorded against the VM and
+ * store them into @msgs array which is allocated upon
+ * successful return and is NULL terminated. The caller is
+ * responsible for freeing @msgs when no longer needed.
+ *
+ * If @flags is zero then all messages are reported. The
+ * virDomainMessageType constants can be used to restrict
+ * results to certain types of message.
+ *
+ * Note it is hypervisor dependant whether messages are
+ * available for shutoff guests, or running guests, or
+ * both. Thus a client should be prepared to re-fetch
+ * messages when a guest transitions between running
+ * and shutoff states.
+ *
+ * Returns: number of messages stored in @msgs,
+ *          -1 otherwise.
+ */
+int
+virDomainGetMessages(virDomainPtr domain,
+                     char ***msgs,
+                     unsigned int flags)
+{
+    virConnectPtr conn;
+
+    VIR_DOMAIN_DEBUG(domain, "msgs=%p, flags=0x%x", msgs, flags);
+
+    virResetLastError();
+
+    virCheckDomainReturn(domain, -1);
+    conn = domain->conn;
+    virCheckNonNullArgGoto(msgs, error);
+
+    if (conn->driver->domainGetMessages) {
+        int ret;
+        ret = conn->driver->domainGetMessages(domain, msgs, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virReportUnsupportedError();
+ error:
+    virDispatchError(conn);
+    return -1;
+}

src/libvirt_public.syms

@@ -879,4 +879,9 @@ LIBVIRT_6.10.0 {
         virDomainAuthorizedSSHKeysSet;
 } LIBVIRT_6.0.0;
 
+LIBVIRT_7.1.0 {
+    global:
+        virDomainGetMessages;
+} LIBVIRT_6.10.0;
+
 # .... define new API here using predicted next version number ....