Adding virDomainSetMemoryParameters and virDomainGetMemoryParameters API

Public api to set/get memory tunables supported by the hypervisors.

dv:
* some cleanups in libvirt.c
* adding extra checks in libvirt.c new entry points

v4:
* Move exporting public API to this patch
* Add unsigned int flags to the public api for future extensions

v3:
* Add domainGetMemoryParamters and NULL in all the driver interface

v2:
* Initialize domainSetMemoryParameters to NULL in all the driver
  interface structure.

AUTHORS

@@ -129,6 +129,7 @@ Patches have also been contributed by:
   Aurelien Rougemont   <beorn@binaries.fr>
   Patrick Dignan       <pat_dignan@dell.com>
   Serge Hallyn         <serge.hallyn@canonical.com>
+  Nikunj A. Dadhania   <nikunj@linux.vnet.ibm.com>
 
   [....send patches to get your name here....]
 

src/driver.h

@@ -127,6 +127,18 @@ typedef int
 typedef int
         (*virDrvDomainSetMemory)	(virDomainPtr domain,
                                          unsigned long memory);
+typedef int
+        (*virDrvDomainSetMemoryParameters)
+                                        (virDomainPtr domain,
+                                         virMemoryParameterPtr params,
+                                         int nparams,
+                                         unsigned int flags);
+typedef int
+        (*virDrvDomainGetMemoryParameters)
+                                        (virDomainPtr domain,
+                                         virMemoryParameterPtr params,
+                                         int *nparams,
+                                         unsigned int flags);
 typedef int
         (*virDrvDomainGetInfo)		(virDomainPtr domain,
                                          virDomainInfoPtr info);
@@ -575,6 +587,8 @@ struct _virDriver {
     virDrvDomainRevertToSnapshot domainRevertToSnapshot;
     virDrvDomainSnapshotDelete domainSnapshotDelete;
     virDrvQemuDomainMonitorCommand qemuDomainMonitorCommand;
+    virDrvDomainSetMemoryParameters domainSetMemoryParameters;
+    virDrvDomainGetMemoryParameters domainGetMemoryParameters;
 };
 
 typedef int

src/esx/esx_driver.c

@@ -4217,6 +4217,8 @@ static virDriver esxDriver = {
     esxDomainRevertToSnapshot,       /* domainRevertToSnapshot */
     esxDomainSnapshotDelete,         /* domainSnapshotDelete */
     NULL,                            /* qemuDomainMonitorCommand */
+    NULL,                            /* domainSetMemoryParameters */
+    NULL,                            /* domainGetMemoryParameters */
 };
 
 

src/libvirt.c

@@ -2999,6 +2999,118 @@ error:
     return -1;
 }
 
+/**
+ * virDomainSetMemoryParameters:
+ * @domain: pointer to domain object
+ * @params: pointer to memory parameter objects
+ * @nparams: number of memory parameter (this value should be same or
+ *          less than the number of parameters supported)
+ * @flags: currently unused, for future extension
+ *
+ * Change the memory tunables
+ * This function requires privileged access to the hypervisor.
+ *
+ * Returns -1 in case of error, 0 in case of success.
+ */
+int
+virDomainSetMemoryParameters(virDomainPtr domain,
+                             virMemoryParameterPtr params,
+                             int nparams, unsigned int flags)
+{
+    virConnectPtr conn;
+    DEBUG("domain=%p, params=%p, nparams=%d, flags=%u", domain, params, nparams, flags);
+
+    virResetLastError();
+
+    if (!VIR_IS_CONNECTED_DOMAIN(domain)) {
+        virLibDomainError(NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+        virDispatchError(NULL);
+        return -1;
+    }
+    if (domain->conn->flags & VIR_CONNECT_RO) {
+        virLibDomainError(domain, VIR_ERR_OPERATION_DENIED, __FUNCTION__);
+        goto error;
+    }
+    if ((nparams <= 0) || (params == NULL)) {
+        virLibDomainError(domain, VIR_ERR_INVALID_ARG, __FUNCTION__);
+        goto error;
+    }
+    conn = domain->conn;
+
+    if (conn->driver->domainSetMemoryParameters) {
+        int ret;
+        ret = conn->driver->domainSetMemoryParameters (domain, params, nparams, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+    virDispatchError(domain->conn);
+    return -1;
+}
+
+/**
+ * virDomainGetMemoryParameters:
+ * @domain: pointer to domain object
+ * @params: pointer to memory parameter object
+ *          (return value, allocated by the caller)
+ * @nparams: pointer to number of memory parameters
+ * @flags: currently unused, for future extension
+ *
+ * Get the memory parameters, the @params array will be filled with the values
+ * equal to the number of parameters suggested by @nparams
+ *
+ * As a special case, if @nparams is zero and @params is NULL, the API will
+ * set the number of parameters supported by the HV in @nparams and return
+ * SUCCESS.
+ *
+ * This function requires privileged access to the hypervisor. This function
+ * expects the caller to allocate the @param
+ *
+ * Returns -1 in case of error, 0 in case of success.
+ */
+int
+virDomainGetMemoryParameters(virDomainPtr domain,
+                             virMemoryParameterPtr params,
+                             int *nparams, unsigned int flags)
+{
+    virConnectPtr conn;
+    DEBUG("domain=%p, params=%p, nparams=%d, flags=%u", domain, params, (nparams)?*nparams:-1, flags);
+
+    virResetLastError();
+
+    if (!VIR_IS_CONNECTED_DOMAIN(domain)) {
+        virLibDomainError(NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+        virDispatchError(NULL);
+        return -1;
+    }
+    if (domain->conn->flags & VIR_CONNECT_RO) {
+        virLibDomainError(domain, VIR_ERR_OPERATION_DENIED, __FUNCTION__);
+        goto error;
+    }
+    if ((nparams == NULL) || (*nparams < 0)) {
+        virLibDomainError(domain, VIR_ERR_INVALID_ARG, __FUNCTION__);
+        goto error;
+    }
+    conn = domain->conn;
+
+    if (conn->driver->domainGetMemoryParameters) {
+        int ret;
+        ret = conn->driver->domainGetMemoryParameters (domain, params, nparams, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+    virLibConnError (conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+    virDispatchError(domain->conn);
+    return -1;
+}
+
 /**
  * virDomainGetInfo:
  * @domain: a domain object

src/libvirt_public.syms

@@ -405,4 +405,10 @@ LIBVIRT_0.8.2 {
         virDomainCreateWithFlags;
 } LIBVIRT_0.8.1;
 
+LIBVIRT_0.8.5 {
+    global:
+        virDomainSetMemoryParameters;
+        virDomainGetMemoryParameters;
+} LIBVIRT_0.8.2;
+
 # .... define new API here using predicted next version number ....

src/lxc/lxc_driver.c

@@ -2620,6 +2620,8 @@ static virDriver lxcDriver = {
     NULL, /* domainRevertToSnapshot */
     NULL, /* domainSnapshotDelete */
     NULL, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParameters */
+    NULL, /* domainGetMemoryParameters */
 };
 
 static virStateDriver lxcStateDriver = {

src/openvz/openvz_driver.c

@@ -1657,6 +1657,8 @@ static virDriver openvzDriver = {
     NULL, /* domainRevertToSnapshot */
     NULL, /* domainSnapshotDelete */
     NULL, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParameters */
+    NULL, /* domainGetMemoryParameters */
 };
 
 int openvzRegister(void) {

src/phyp/phyp_driver.c

@@ -4007,6 +4007,8 @@ static virDriver phypDriver = {
     NULL,                       /* domainRevertToSnapshot */
     NULL,                       /* domainSnapshotDelete */
     NULL,                       /* qemuMonitorCommand */
+    NULL,                       /* domainSetMemoryParameters */
+    NULL,                       /* domainGetMemoryParameters */
 };
 
 static virStorageDriver phypStorageDriver = {

src/qemu/qemu_driver.c

@@ -12710,6 +12710,8 @@ static virDriver qemuDriver = {
     qemuDomainRevertToSnapshot, /* domainRevertToSnapshot */
     qemuDomainSnapshotDelete, /* domainSnapshotDelete */
     qemuDomainMonitorCommand, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParameters */
+    NULL, /* domainGetMemoryParameters */
 };
 
 

src/remote/remote_driver.c

@@ -10366,6 +10366,8 @@ static virDriver remote_driver = {
     remoteDomainRevertToSnapshot, /* domainRevertToSnapshot */
     remoteDomainSnapshotDelete, /* domainSnapshotDelete */
     remoteQemuDomainMonitorCommand, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParameters */
+    NULL, /* domainGetMemoryParameters */
 };
 
 static virNetworkDriver network_driver = {

src/test/test_driver.c

@@ -5327,6 +5327,8 @@ static virDriver testDriver = {
     NULL, /* domainRevertToSnapshot */
     NULL, /* domainSnapshotDelete */
     NULL, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParameters */
+    NULL, /* domainGetMemoryParameters */
 };
 
 static virNetworkDriver testNetworkDriver = {

src/uml/uml_driver.c

@@ -2196,6 +2196,8 @@ static virDriver umlDriver = {
     NULL, /* domainRevertToSnapshot */
     NULL, /* domainSnapshotDelete */
     NULL, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParamters */
+    NULL, /* domainGetMemoryParamters */
 };
 
 static int

src/xen/xen_driver.c

@@ -2018,6 +2018,8 @@ static virDriver xenUnifiedDriver = {
     NULL, /* domainRevertToSnapshot */
     NULL, /* domainSnapshotDelete */
     NULL, /* qemuDomainMonitorCommand */
+    NULL, /* domainSetMemoryParameters */
+    NULL, /* domainGetMemoryParameters */
 };
 
 /**