[PATCH] libxl: Improve reporting of die_id in capabilities

[Jim Fehlig]

On Xen, libvirt runs in a VM (typically dom0) and does not have an accurate
picture of numa and cpu topology of the underlying physical machine using
the "usual" mechanisms. numa info and cpu toplogy are retrieved from libxl
and used to populate the libvirt conterparts. Commit 7b79ee2f78b introduced
support for reporting die_id in capabilities, but did not account for
special handling of numa and cpu topology in libxl.

Currently, Xen does not report die_id in the libxl_cputopology structure.
In the meantime, set die_id to 0, which was suggested by the Xen developers
and is slightly better than random garbage such as

<cpu id='1' socket_id='0' die_id='-1073069552' core_id='0' siblings='0-1'/>

Signed-off-by: Jim Fehlig <jfehlig at suse.com>
---
 src/libxl/libxl_capabilities.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/libxl/libxl_capabilities.c b/src/libxl/libxl_capabilities.c
index b4bd1d7e62..4afed71436 100644
--- a/src/libxl/libxl_capabilities.c
+++ b/src/libxl/libxl_capabilities.c
@@ -292,6 +292,8 @@ libxlCapsInitNuma(libxl_ctx *ctx, virCaps *caps)
         cpus[node][nr_cpus_node[node]-1].id = i;
         cpus[node][nr_cpus_node[node]-1].socket_id = cpu_topo[i].socket;
         cpus[node][nr_cpus_node[node]-1].core_id = cpu_topo[i].core;
+        /* Until Xen reports die_id, 0 is better than random garbage */
+        cpus[node][nr_cpus_node[node]-1].die_id = 0;
         /* Allocate the siblings maps. We will be filling them later */
         cpus[node][nr_cpus_node[node]-1].siblings = virBitmapNew(nr_cpus);
     }
-- 
2.33.0