path: root/hw/ppc/spapr_numa.c

/*
 * QEMU PowerPC pSeries Logical Partition NUMA associativity handling
 *
 * Copyright IBM Corp. 2020
 *
 * Authors:
 *  Daniel Henrique Barboza      <danielhb413@gmail.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "qemu-common.h"
#include "hw/ppc/spapr_numa.h"
#include "hw/ppc/fdt.h"


void spapr_numa_associativity_init(SpaprMachineState *spapr,
                                   MachineState *machine)
{
    int nb_numa_nodes = machine->numa_state->num_nodes;
    int i;

    /*
     * For all associativity arrays: first position is the size,
     * position MAX_DISTANCE_REF_POINTS is always the numa_id,
     * represented by the index 'i'.
     *
     * This will break on sparse NUMA setups, when/if QEMU starts
     * to support it, because there will be no more guarantee that
     * 'i' will be a valid node_id set by the user.
     */
    for (i = 0; i < nb_numa_nodes; i++) {
        spapr->numa_assoc_array[i][0] = cpu_to_be32(MAX_DISTANCE_REF_POINTS);
        spapr->numa_assoc_array[i][MAX_DISTANCE_REF_POINTS] = cpu_to_be32(i);
    }
}

void spapr_numa_write_associativity_dt(SpaprMachineState *spapr, void *fdt,
                                       int offset, int nodeid)
{
    _FDT((fdt_setprop(fdt, offset, "ibm,associativity",
                      spapr->numa_assoc_array[nodeid],
                      sizeof(spapr->numa_assoc_array[nodeid]))));
}

int spapr_numa_fixup_cpu_dt(SpaprMachineState *spapr, void *fdt,
                            int offset, PowerPCCPU *cpu)
{
    int vcpu_assoc_size = NUMA_ASSOC_SIZE + 1;
    uint32_t vcpu_assoc[vcpu_assoc_size];
    int index = spapr_get_vcpu_id(cpu);
    int i;

    /*
     * VCPUs have an extra 'cpu_id' value in ibm,associativity
     * compared to other resources. Increment the size at index
     * 0, copy all associativity domains already set, then put
     * cpu_id last.
     */
    vcpu_assoc[0] = cpu_to_be32(MAX_DISTANCE_REF_POINTS + 1);

    for (i = 1; i <= MAX_DISTANCE_REF_POINTS; i++) {
        vcpu_assoc[i] = spapr->numa_assoc_array[cpu->node_id][i];
    }

    vcpu_assoc[vcpu_assoc_size - 1] = cpu_to_be32(index);

    /* Advertise NUMA via ibm,associativity */
    return fdt_setprop(fdt, offset, "ibm,associativity",
                       vcpu_assoc, sizeof(vcpu_assoc));
}

/*
 * Helper that writes ibm,associativity-reference-points and
 * max-associativity-domains in the RTAS pointed by @rtas
 * in the DT @fdt.
 */
void spapr_numa_write_rtas_dt(SpaprMachineState *spapr, void *fdt, int rtas)
{
    SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
    uint32_t refpoints[] = {
        cpu_to_be32(0x4),
        cpu_to_be32(0x4),
        cpu_to_be32(0x2),
    };
    uint32_t nr_refpoints = ARRAY_SIZE(refpoints);
    uint32_t maxdomain = cpu_to_be32(spapr->gpu_numa_id > 1 ? 1 : 0);
    uint32_t maxdomains[] = {
        cpu_to_be32(4),
        maxdomain,
        maxdomain,
        maxdomain,
        cpu_to_be32(spapr->gpu_numa_id),
    };

    if (smc->pre_5_1_assoc_refpoints) {
        nr_refpoints = 2;
    }

    _FDT(fdt_setprop(fdt, rtas, "ibm,associativity-reference-points",
                     refpoints, nr_refpoints * sizeof(refpoints[0])));

    _FDT(fdt_setprop(fdt, rtas, "ibm,max-associativity-domains",
                     maxdomains, sizeof(maxdomains)));
}