From ee6635b227491e7d487ecd868e0dbfbb0c444217 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Wed, 7 Oct 2020 14:28:46 -0300 Subject: [PATCH] spapr_numa: forbid asymmetrical NUMA setups The pSeries machine does not support asymmetrical NUMA configurations. This doesn't make much of a different since we're not using user input for pSeries NUMA setup, but this will change in the next patches. To avoid breaking existing setups, gate this change by checking for legacy NUMA support. Reviewed-by: Greg Kurz Reviewed-by: David Gibson Signed-off-by: Daniel Henrique Barboza Message-Id: <20201007172849.302240-3-danielhb413@gmail.com> Signed-off-by: David Gibson --- hw/ppc/spapr_numa.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c index 64fe567f5d..fe395e80a3 100644 --- a/hw/ppc/spapr_numa.c +++ b/hw/ppc/spapr_numa.c @@ -19,6 +19,24 @@ /* Moved from hw/ppc/spapr_pci_nvlink2.c */ #define SPAPR_GPU_NUMA_ID (cpu_to_be32(1)) +static bool spapr_numa_is_symmetrical(MachineState *ms) +{ + int src, dst; + int nb_numa_nodes = ms->numa_state->num_nodes; + NodeInfo *numa_info = ms->numa_state->nodes; + + for (src = 0; src < nb_numa_nodes; src++) { + for (dst = src; dst < nb_numa_nodes; dst++) { + if (numa_info[src].distance[dst] != + numa_info[dst].distance[src]) { + return false; + } + } + } + + return true; +} + void spapr_numa_associativity_init(SpaprMachineState *spapr, MachineState *machine) { @@ -61,6 +79,22 @@ void spapr_numa_associativity_init(SpaprMachineState *spapr, spapr->numa_assoc_array[i][MAX_DISTANCE_REF_POINTS] = cpu_to_be32(i); } + + /* + * Legacy NUMA guests (pseries-5.1 and older, or guests with only + * 1 NUMA node) will not benefit from anything we're going to do + * after this point. + */ + if (spapr_machine_using_legacy_numa(spapr)) { + return; + } + + if (!spapr_numa_is_symmetrical(machine)) { + error_report("Asymmetrical NUMA topologies aren't supported " + "in the pSeries machine"); + exit(EXIT_FAILURE); + } + } void spapr_numa_write_associativity_dt(SpaprMachineState *spapr, void *fdt,