From 0d5ba48112daf820daddb5c952265fa23e092e69 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Mon, 20 Sep 2021 14:49:47 -0300 Subject: [PATCH] spapr_numa.c: handle auto NUMA node with no distance info numa_complete_configuration() in hw/core/numa.c always adds a NUMA node for the pSeries machine if none was specified, but without node distance information for the single node created. NUMA FORM1 affinity code didn't rely on numa_state information to do its job, but FORM2 does. As is now, this is the result of a pSeries guest with NUMA FORM2 affinity when no NUMA nodes is specified: $ numactl -H available: 1 nodes (0) node 0 cpus: 0 node 0 size: 16222 MB node 0 free: 15681 MB No distance information available. This can be amended in spapr_numa_FORM2_write_rtas_tables(). We're enforcing that the local distance (the distance to the node to itself) is always 10. This allows for the proper creation of the NUMA distance tables, fixing the output of 'numactl -H' in the guest: $ numactl -H available: 1 nodes (0) node 0 cpus: 0 node 0 size: 16222 MB node 0 free: 15685 MB node distances: node 0 0: 10 CC: Igor Mammedov Reviewed-by: Greg Kurz Signed-off-by: Daniel Henrique Barboza Message-Id: <20210920174947.556324-8-danielhb413@gmail.com> Acked-by: Igor Mammedov Signed-off-by: David Gibson --- hw/ppc/spapr_numa.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c index 13db321997..58d5dc7084 100644 --- a/hw/ppc/spapr_numa.c +++ b/hw/ppc/spapr_numa.c @@ -539,6 +539,17 @@ static void spapr_numa_FORM2_write_rtas_tables(SpaprMachineState *spapr, for (src = 0; src < nb_numa_nodes; src++) { for (dst = 0; dst < nb_numa_nodes; dst++) { + /* + * We need to be explicit with the local distance + * value to cover the case where the user didn't added any + * NUMA nodes, but QEMU adds the default NUMA node without + * adding the numa_info to retrieve distance info from. + */ + if (src == dst) { + node_distances[i++] = 10; + continue; + } + node_distances[i++] = numa_info[src].distance[dst]; } }