From 261c4f5fb93c5e23b8002f2760d4a7937cdb7f63 Mon Sep 17 00:00:00 2001 From: Dario Faggioli Date: Sat, 13 Jul 2013 02:27:18 +0200 Subject: [PATCH] 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 --- src/libxl/libxl_driver.c | 141 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index a5addab21b..358d3879d5 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -28,6 +28,7 @@ #include #include +#include #include #include @@ -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 = ¶ms[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 */