[libvirt] [RFC PATCH v2 2/4] libxl: vnuma support

Wim Ten Have wim.ten.have at oracle.com
Wed Jun 28 13:56:37 UTC 2017


From: Wim ten Have <wim.ten.have at oracle.com>

This patch generates a NUMA distance-aware libxl description from the
information extracted from a NUMA distance-aware libvirt XML file.

By default, if no NUMA node distance information is supplied in the
libvirt XML file, this patch uses the distances 10 for local and 21 for
remote nodes/sockets."

Signed-off-by: Wim ten Have <wim.ten.have at oracle.com>
---
 src/libxl/libxl_conf.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)

diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index 938e09d..7d22229 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -617,6 +617,125 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
     return 0;
 }
 
+#ifdef LIBXL_HAVE_VNUMA
+static int
+libxlMakeVnumaList(virDomainDefPtr def,
+                   libxl_ctx *ctx,
+                   libxl_domain_config *d_config)
+{
+    int ret = -1;
+    size_t i, j;
+    size_t nr_nodes;
+    size_t num_vnuma;
+    virBitmapPtr bitmap = NULL;
+    virDomainNumaPtr numa = def->numa;
+    libxl_domain_build_info *b_info = &d_config->b_info;
+    libxl_physinfo physinfo;
+    libxl_vnode_info *vnuma_nodes = NULL;
+
+    if (!numa)
+        return 0;
+
+    num_vnuma = virDomainNumaGetNodeCount(numa);
+    if (!num_vnuma)
+        return 0;
+
+    libxl_physinfo_init(&physinfo);
+    if (libxl_get_physinfo(ctx, &physinfo) < 0) {
+        libxl_physinfo_dispose(&physinfo);
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("libxl_get_physinfo_info failed"));
+        return -1;
+    }
+    nr_nodes = physinfo.nr_nodes;
+    libxl_physinfo_dispose(&physinfo);
+
+    if (num_vnuma > nr_nodes) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("Number of configured numa cells %zu exceeds the physical available nodes %zu"),
+                       num_vnuma, nr_nodes);
+        return -1;
+    }
+
+    /*
+     * allocate the vnuma_nodes for assignment under b_info.
+     */
+    if (VIR_ALLOC_N(vnuma_nodes, num_vnuma) < 0)
+        return -1;
+
+    /*
+     * parse the vnuma vnodes data.
+     */
+    for (i = 0; i < num_vnuma; i++) {
+        int cpu;
+        libxl_bitmap vcpu_bitmap;
+        libxl_vnode_info *p = &vnuma_nodes[i];
+
+        libxl_vnode_info_init(p);
+
+        /* pnode */
+        p->pnode = i;
+
+        /* memory size */
+        p->memkb = virDomainNumaGetNodeMemorySize(numa, i);
+
+        /* vcpus */
+        bitmap = virDomainNumaGetNodeCpumask(numa, i);
+        if (bitmap == NULL) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("vnuma sibling %zu missing vcpus set"), i);
+            goto cleanup;
+        }
+
+        if ((cpu = virBitmapNextSetBit(bitmap, -1)) < 0)
+            goto cleanup;
+
+        libxl_bitmap_init(&vcpu_bitmap);
+        if (libxl_cpu_bitmap_alloc(ctx, &vcpu_bitmap, b_info->max_vcpus)) {
+            virReportOOMError();
+            goto cleanup;
+        }
+
+        do {
+            libxl_bitmap_set(&vcpu_bitmap, cpu);
+        } while ((cpu = virBitmapNextSetBit(bitmap, cpu)) >= 0);
+
+        libxl_bitmap_copy_alloc(ctx, &p->vcpus, &vcpu_bitmap);
+        libxl_bitmap_dispose(&vcpu_bitmap);
+
+        /* vdistances */
+        if (VIR_ALLOC_N(p->distances, num_vnuma) < 0)
+            goto cleanup;
+        p->num_distances = num_vnuma;
+
+        /*
+         * Apply the configured distance value. If not
+         * available set 10 for local or 21 for remote nodes.
+         */
+        for (j = 0; j < num_vnuma; j++)
+            if (!(p->distances[j] = virDomainNumaGetNodeDistance(numa, i, j)))
+                p->distances[j] = (i == j) ? 10 : 21;
+    }
+
+    b_info->vnuma_nodes = vnuma_nodes;
+    b_info->num_vnuma_nodes = num_vnuma;
+
+    ret = 0;
+
+ cleanup:
+    if (ret) {
+        for (i = 0; i < num_vnuma; i++) {
+            libxl_vnode_info *p = &vnuma_nodes[i];
+
+            VIR_FREE(p->distances);
+        }
+        VIR_FREE(vnuma_nodes);
+    }
+
+    return ret;
+}
+#endif
+
 static int
 libxlDiskSetDiscard(libxl_device_disk *x_disk, int discard)
 {
@@ -2207,6 +2326,11 @@ libxlBuildDomainConfig(virPortAllocatorPtr graphicsports,
     if (libxlMakeDomBuildInfo(def, ctx, caps, d_config) < 0)
         return -1;
 
+#ifdef LIBXL_HAVE_VNUMA
+    if (libxlMakeVnumaList(def, ctx, d_config) < 0)
+        return -1;
+#endif
+
     if (libxlMakeDiskList(def, d_config) < 0)
         return -1;
 
-- 
2.9.4




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