libxl: implement virDomainGetNumaParameters

Although, having it depending on Xen >= 4.3 (by using the proper
libxl feature flag).

Xen currently implements a NUMA placement policy which is basically
the same as the 'interleaved' policy of `numactl', although it can
be applied on a subset of the available nodes. We therefore hardcode
"interleave" as 'numa_mode', and we use the newly introduced libxl
interface to figure out what nodes a domain spans ('numa_nodeset').

With this change, it is now possible to query the NUMA node
affinity of a running domain:

[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// list
 Id    Name                           State
----------------------------------------------------
 23    F18_x64                        running

[raistlin@Zhaman ~]$ sudo virsh --connect xen:/// numatune 23
numa_mode      : interleave
numa_nodeset   : 1

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
This commit is contained in:
Dario Faggioli 2013-07-13 02:27:18 +02:00 committed by Jim Fehlig
parent 98984b71a8
commit 261c4f5fb9

View File

@ -28,6 +28,7 @@
#include <math.h>
#include <libxl.h>
#include <libxl_utils.h>
#include <fcntl.h>
#include <regex.h>
@ -4499,6 +4500,143 @@ libxlDomainSetSchedulerParameters(virDomainPtr dom, virTypedParameterPtr params,
return libxlDomainSetSchedulerParametersFlags(dom, params, nparams, 0);
}
/* NUMA node affinity information is available through libxl
* starting from Xen 4.3. */
#ifdef LIBXL_HAVE_DOMAIN_NODEAFFINITY
/* Number of Xen NUMA parameters */
# define LIBXL_NUMA_NPARAM 2
static int
libxlDomainGetNumaParameters(virDomainPtr dom,
virTypedParameterPtr params,
int *nparams,
unsigned int flags)
{
libxlDriverPrivatePtr driver = dom->conn->privateData;
libxlDomainObjPrivatePtr priv;
virDomainObjPtr vm;
libxl_bitmap nodemap;
virBitmapPtr nodes = NULL;
char *nodeset = NULL;
int rc, ret = -1;
size_t i, j;
/* In Xen 4.3, it is possible to query the NUMA node affinity of a domain
* via libxl, but not to change it. We therefore only allow AFFECT_LIVE. */
virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
VIR_TYPED_PARAM_STRING_OKAY, -1);
/* We blindly return a string, and let libvirt.c and remote_driver.c do
* the filtering on behalf of older clients that can't parse it. */
flags &= ~VIR_TYPED_PARAM_STRING_OKAY;
libxlDriverLock(driver);
vm = virDomainObjListFindByUUID(driver->domains, dom->uuid);
libxlDriverUnlock(driver);
if (!vm) {
virReportError(VIR_ERR_NO_DOMAIN, "%s",
_("no domain with matching uuid"));
goto cleanup;
}
if (virDomainGetNumaParametersEnsureACL(dom->conn, vm->def) < 0)
goto cleanup;
if (!virDomainObjIsActive(vm)) {
virReportError(VIR_ERR_OPERATION_INVALID, "%s",
_("Domain is not running"));
goto cleanup;
}
priv = vm->privateData;
libxl_bitmap_init(&nodemap);
if ((*nparams) == 0) {
*nparams = LIBXL_NUMA_NPARAM;
ret = 0;
goto cleanup;
}
for (i = 0; i < LIBXL_NUMA_NPARAM && i < *nparams; i++) {
virMemoryParameterPtr param = &params[i];
switch (i) {
case 0:
/* NUMA mode */
/* Xen implements something that is really close to numactl's
* 'interleave' policy (see `man 8 numactl' for details). */
if (virTypedParameterAssign(param, VIR_DOMAIN_NUMA_MODE,
VIR_TYPED_PARAM_INT,
VIR_DOMAIN_NUMATUNE_MEM_INTERLEAVE) < 0)
goto cleanup;
break;
case 1:
/* Node affinity */
/* Let's allocate both libxl and libvirt bitmaps */
if (libxl_node_bitmap_alloc(priv->ctx, &nodemap, 0) ||
!(nodes = virBitmapNew(libxl_get_max_nodes(priv->ctx)))) {
virReportOOMError();
goto cleanup;
}
rc = libxl_domain_get_nodeaffinity(priv->ctx,
vm->def->id,
&nodemap);
if (rc != 0) {
virReportSystemError(-rc, "%s",
_("unable to get numa affinity"));
goto cleanup;
}
/* First, we convert libxl_bitmap into virBitmap. After that,
* we format virBitmap as a string that can be returned. */
virBitmapClearAll(nodes);
libxl_for_each_set_bit(j, nodemap) {
if (virBitmapSetBit(nodes, j)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Node %zu out of range"), j);
goto cleanup;
}
}
nodeset = virBitmapFormat(nodes);
if (!nodeset && VIR_STRDUP(nodeset, "") < 0)
goto cleanup;
if (virTypedParameterAssign(param, VIR_DOMAIN_NUMA_NODESET,
VIR_TYPED_PARAM_STRING, nodeset) < 0)
goto cleanup;
nodeset = NULL;
break;
default:
break;
}
}
if (*nparams > LIBXL_NUMA_NPARAM)
*nparams = LIBXL_NUMA_NPARAM;
ret = 0;
cleanup:
VIR_FREE(nodeset);
virBitmapFree(nodes);
libxl_bitmap_dispose(&nodemap);
if (vm)
virObjectUnlock(vm);
return ret;
}
#endif
static int
libxlDomainIsActive(virDomainPtr dom)
{
@ -4727,6 +4865,9 @@ static virDriver libxlDriver = {
.domainGetSchedulerParametersFlags = libxlDomainGetSchedulerParametersFlags, /* 0.9.2 */
.domainSetSchedulerParameters = libxlDomainSetSchedulerParameters, /* 0.9.0 */
.domainSetSchedulerParametersFlags = libxlDomainSetSchedulerParametersFlags, /* 0.9.2 */
#ifdef LIBXL_HAVE_DOMAIN_NODEAFFINITY
.domainGetNumaParameters = libxlDomainGetNumaParameters, /* 1.1.1 */
#endif
.nodeGetFreeMemory = libxlNodeGetFreeMemory, /* 0.9.0 */
.nodeGetCellsFreeMemory = libxlNodeGetCellsFreeMemory, /* 1.1.1 */
.connectDomainEventRegister = libxlConnectDomainEventRegister, /* 0.9.0 */