migration/dirtyrate: Introduce virDomainStartDirtyRateCalc API

Introduce virDomainStartDirtyRateCalc API for start calculation of
a domain's memory dirty rate with a specified time.

Signed-off-by: Hao Wang <wanghao232@huawei.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

include/libvirt/libvirt-domain.h

@@ -5128,4 +5128,8 @@ int virDomainGetMessages(virDomainPtr domain,
                          char ***msgs,
                          unsigned int flags);
 
+int virDomainStartDirtyRateCalc(virDomainPtr domain,
+                                int seconds,
+                                unsigned int flags);
+
 #endif /* LIBVIRT_DOMAIN_H */

src/driver-hypervisor.h

@@ -1405,6 +1405,11 @@ typedef int
                            char ***msgs,
                            unsigned int flags);
 
+typedef int
+(*virDrvDomainStartDirtyRateCalc)(virDomainPtr domain,
+                                  int seconds,
+                                  unsigned int flags);
+
 typedef struct _virHypervisorDriver virHypervisorDriver;
 typedef virHypervisorDriver *virHypervisorDriverPtr;
 
@@ -1671,4 +1676,5 @@ struct _virHypervisorDriver {
     virDrvDomainAuthorizedSSHKeysGet domainAuthorizedSSHKeysGet;
     virDrvDomainAuthorizedSSHKeysSet domainAuthorizedSSHKeysSet;
     virDrvDomainGetMessages domainGetMessages;
+    virDrvDomainStartDirtyRateCalc domainStartDirtyRateCalc;
 };

src/libvirt-domain.c

@@ -13158,3 +13158,47 @@ virDomainGetMessages(virDomainPtr domain,
     virDispatchError(conn);
     return -1;
 }
+
+
+/**
+ * virDomainStartDirtyRateCalc:
+ * @domain: a domain object
+ * @seconds: specified calculating time in seconds
+ * @flags: extra flags; not used yet, so callers should always pass 0
+ *
+ * Calculate the current domain's memory dirty rate in next @seconds.
+ * The calculated dirty rate information is available by calling
+ * virConnectGetAllDomainStats.
+ *
+ * Returns 0 in case of success, -1 otherwise.
+ */
+int
+virDomainStartDirtyRateCalc(virDomainPtr domain,
+                            int seconds,
+                            unsigned int flags)
+{
+    virConnectPtr conn;
+
+    VIR_DOMAIN_DEBUG(domain, "seconds=%d, flags=0x%x", seconds, flags);
+
+    virResetLastError();
+
+    virCheckDomainReturn(domain, -1);
+    conn = domain->conn;
+
+    virCheckReadOnlyGoto(conn->flags, error);
+
+    if (conn->driver->domainStartDirtyRateCalc) {
+        int ret;
+        ret = conn->driver->domainStartDirtyRateCalc(domain, seconds, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virReportUnsupportedError();
+
+ error:
+    virDispatchError(conn);
+    return -1;
+}

src/libvirt_public.syms

@@ -884,4 +884,9 @@ LIBVIRT_7.1.0 {
         virDomainGetMessages;
 } LIBVIRT_6.10.0;
 
+LIBVIRT_7.2.0 {
+    global:
+        virDomainStartDirtyRateCalc;
+} LIBVIRT_7.1.0;
+
 # .... define new API here using predicted next version number ....

src/remote/remote_driver.c

@@ -8571,6 +8571,7 @@ static virHypervisorDriver hypervisor_driver = {
     .domainAuthorizedSSHKeysGet = remoteDomainAuthorizedSSHKeysGet, /* 6.10.0 */
     .domainAuthorizedSSHKeysSet = remoteDomainAuthorizedSSHKeysSet, /* 6.10.0 */
     .domainGetMessages = remoteDomainGetMessages, /* 7.1.0 */
+    .domainStartDirtyRateCalc = remoteDomainStartDirtyRateCalc, /* 7.2.0 */
 };
 
 static virNetworkDriver network_driver = {

src/remote/remote_protocol.x

@@ -3811,6 +3811,12 @@ struct remote_domain_get_messages_ret {
     remote_nonnull_string msgs<REMOTE_DOMAIN_MESSAGES_MAX>;
 };
 
+struct remote_domain_start_dirty_rate_calc_args {
+    remote_nonnull_domain dom;
+    int seconds;
+    unsigned int flags;
+};
+
 
 /*----- Protocol. -----*/
 
@@ -6733,5 +6739,11 @@ enum remote_procedure {
      * @generate: none
      * @acl: domain:read
      */
-    REMOTE_PROC_DOMAIN_GET_MESSAGES = 426
+    REMOTE_PROC_DOMAIN_GET_MESSAGES = 426,
+
+    /**
+     * @generate: both
+     * @acl: domain:read
+     */
+    REMOTE_PROC_DOMAIN_START_DIRTY_RATE_CALC = 427
 };

src/remote_protocol-structs

@@ -3172,6 +3172,11 @@ struct remote_domain_get_messages_ret {
                 remote_nonnull_string * msgs_val;
         } msgs;
 };
+struct remote_domain_start_dirty_rate_calc_args {
+        remote_nonnull_domain      dom;
+        int                        seconds;
+        u_int                      flags;
+};
 enum remote_procedure {
         REMOTE_PROC_CONNECT_OPEN = 1,
         REMOTE_PROC_CONNECT_CLOSE = 2,
@@ -3599,4 +3604,5 @@ enum remote_procedure {
         REMOTE_PROC_DOMAIN_AUTHORIZED_SSH_KEYS_GET = 424,
         REMOTE_PROC_DOMAIN_AUTHORIZED_SSH_KEYS_SET = 425,
         REMOTE_PROC_DOMAIN_GET_MESSAGES = 426,
+        REMOTE_PROC_DOMAIN_START_DIRTY_RATE_CALC = 427,
 };