On Mon, Sep 06, 2021 at 09:25:27PM -0300, Daniel Henrique Barboza wrote:
> FORM2 NUMA affinity is prepared to deal with empty (memory/cpu less)
> NUMA nodes. This is used by the DAX KMEM driver to locate a PAPR SCM
> device that has a different latency than the original NUMA node from the
> regular memory. FORM2 is also enable to deal with asymmetric NUMA
> distances gracefully, something that our FORM1 implementation doesn't
> do.
>
> Move these FORM1 verifications to a new function and wait until after
> CAS, when we're sure that we're sticking with FORM1, to enforce them.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com>
> ---
> hw/ppc/spapr.c | 33 -------------------------
> hw/ppc/spapr_hcall.c | 6 +++++
> hw/ppc/spapr_numa.c | 49 ++++++++++++++++++++++++++++++++-----
> include/hw/ppc/spapr_numa.h | 1 +
> 4 files changed, 50 insertions(+), 39 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 8d98e3b08a..c974c07fb8 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2797,39 +2797,6 @@ static void spapr_machine_init(MachineState *machine)
> /* init CPUs */
> spapr_init_cpus(spapr);
>
> - /*
> - * check we don't have a memory-less/cpu-less NUMA node
> - * Firmware relies on the existing memory/cpu topology to provide the
> - * NUMA topology to the kernel.
> - * And the linux kernel needs to know the NUMA topology at start
> - * to be able to hotplug CPUs later.
> - */
> - if (machine->numa_state->num_nodes) {
> - for (i = 0; i < machine->numa_state->num_nodes; ++i) {
> - /* check for memory-less node */
> - if (machine->numa_state->nodes[i].node_mem == 0) {
> - CPUState *cs;
> - int found = 0;
> - /* check for cpu-less node */
> - CPU_FOREACH(cs) {
> - PowerPCCPU *cpu = POWERPC_CPU(cs);
> - if (cpu->node_id == i) {
> - found = 1;
> - break;
> - }
> - }
> - /* memory-less and cpu-less node */
> - if (!found) {
> - error_report(
> - "Memory-less/cpu-less nodes are not supported (node
> %d)",
> - i);
> - exit(1);
> - }
> - }
> - }
> -
> - }
> -
> spapr->gpu_numa_id = spapr_numa_initial_nvgpu_numa_id(machine);
>
> if ((!kvm_enabled() || kvmppc_has_cap_mmu_radix()) &&
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 7efbe93f4b..27ee713600 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1202,9 +1202,15 @@ target_ulong do_client_architecture_support(PowerPCCPU
> *cpu,
> * If the guest chooses FORM2 we need to reset the associativity
> * information - it is being defaulted to FORM1 during
> * spapr_machine_reset().
> + *
> + * If we're sure that we'll be using FORM1, verify now if we have
> + * a configuration or condition that is not available for FORM1
> + * (namely asymmetric NUMA topologies and empty NUMA nodes).
> */
> if (spapr_ovec_test(spapr->ov5_cas, OV5_FORM2_AFFINITY)) {
> spapr_numa_associativity_reset(spapr);
> + } else {
> + spapr_numa_check_FORM1_constraints(MACHINE(spapr));
Couldn't you put this call into one of the existing FORM1 functions?
> }
>
> /*
> diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c
> index ca276e16cb..0c57d03184 100644
> --- a/hw/ppc/spapr_numa.c
> +++ b/hw/ppc/spapr_numa.c
> @@ -155,6 +155,49 @@ static void
> spapr_numa_define_associativity_domains(SpaprMachineState *spapr)
>
> }
>
> +void spapr_numa_check_FORM1_constraints(MachineState *machine)
> +{
> + int i;
> +
> + if (!spapr_numa_is_symmetrical(machine)) {
> + error_report("Asymmetrical NUMA topologies aren't supported "
> + "in the pSeries machine");
Error message needs an update since they are now possible with FORM2.
> + exit(EXIT_FAILURE);
> + }
> +
> + /*
> + * check we don't have a memory-less/cpu-less NUMA node
> + * Firmware relies on the existing memory/cpu topology to provide the
> + * NUMA topology to the kernel.
> + * And the linux kernel needs to know the NUMA topology at start
> + * to be able to hotplug CPUs later.
> + */
> + if (machine->numa_state->num_nodes) {
> + for (i = 0; i < machine->numa_state->num_nodes; ++i) {
> + /* check for memory-less node */
> + if (machine->numa_state->nodes[i].node_mem == 0) {
> + CPUState *cs;
> + int found = 0;
> + /* check for cpu-less node */
> + CPU_FOREACH(cs) {
> + PowerPCCPU *cpu = POWERPC_CPU(cs);
> + if (cpu->node_id == i) {
> + found = 1;
> + break;
> + }
> + }
> + /* memory-less and cpu-less node */
> + if (!found) {
> + error_report(
> + "Memory-less/cpu-less nodes are not supported (node
> %d)",
> + i);
> + exit(EXIT_FAILURE);
> + }
> + }
> + }
> + }
> +}
> +
> /*
> * Set NUMA machine state data based on FORM1 affinity semantics.
> */
> @@ -172,12 +215,6 @@ static void
> spapr_numa_FORM1_affinity_init(SpaprMachineState *spapr,
> return;
> }
>
> - if (!spapr_numa_is_symmetrical(machine)) {
> - error_report("Asymmetrical NUMA topologies aren't supported "
> - "in the pSeries machine");
> - exit(EXIT_FAILURE);
> - }
> -
> spapr_numa_define_associativity_domains(spapr);
> }
>
> diff --git a/include/hw/ppc/spapr_numa.h b/include/hw/ppc/spapr_numa.h
> index 0e457bba57..b5a19cb3f1 100644
> --- a/include/hw/ppc/spapr_numa.h
> +++ b/include/hw/ppc/spapr_numa.h
> @@ -25,5 +25,6 @@ int spapr_numa_fixup_cpu_dt(SpaprMachineState *spapr, void
> *fdt,
> int spapr_numa_write_assoc_lookup_arrays(SpaprMachineState *spapr, void *fdt,
> int offset);
> unsigned int spapr_numa_initial_nvgpu_numa_id(MachineState *machine);
> +void spapr_numa_check_FORM1_constraints(MachineState *machine);
>
> #endif /* HW_SPAPR_NUMA_H */
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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