Re: [PATCH v2 2/3] hw/acpi/aml-build: Use existing CPU topology to build PPTT table

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 18 Mar 2022 14:34:12 +0800
"wangyanan (Y)" <wangyanan55@huawei.com> wrote:

> Hi Gavin,
> 
> On 2022/3/3 11:11, Gavin Shan wrote:
> > When the PPTT table is built, the CPU topology is re-calculated, but
> > it's unecessary because the CPU topology, except the cluster IDs,
> > has been populated in virt_possible_cpu_arch_ids() on arm/virt machine.
> >
> > This avoids to re-calculate the CPU topology by reusing the existing
> > one in ms->possible_cpus. However, the cluster ID for the CPU instance
> > has to be calculated dynamically because there is no corresponding
> > field in struct CpuInstanceProperties. Currently, the only user of
> > build_pptt() is arm/virt machine.
> >
> > Signed-off-by: Gavin Shan <gshan@redhat.com>
> > ---
> >   hw/acpi/aml-build.c | 106 ++++++++++++++++++++++++++++++++++----------
> >   1 file changed, 82 insertions(+), 24 deletions(-)
> >
> > diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> > index 8966e16320..572cf5fc00 100644
> > --- a/hw/acpi/aml-build.c
> > +++ b/hw/acpi/aml-build.c
> > @@ -2002,18 +2002,27 @@ void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms,
> >                   const char *oem_id, const char *oem_table_id)
> >   {
> >       MachineClass *mc = MACHINE_GET_CLASS(ms);
> > +    CPUArchIdList *cpus = ms->possible_cpus;
> > +    GQueue *socket_list = g_queue_new();
> > +    GQueue *cluster_list = g_queue_new();
> > +    GQueue *core_list = g_queue_new();
> >       GQueue *list = g_queue_new();
> >       guint pptt_start = table_data->len;
> >       guint parent_offset;
> >       guint length, i;
> > -    int uid = 0;
> > -    int socket;
> > +    int n, id, socket_id, cluster_id, core_id, thread_id;
> >       AcpiTable table = { .sig = "PPTT", .rev = 2,
> >                           .oem_id = oem_id, .oem_table_id = oem_table_id };
> >   
> >       acpi_table_begin(&table, table_data);
> >   
> > -    for (socket = 0; socket < ms->smp.sockets; socket++) {
> > +    for (n = 0; n < cpus->len; n++) {
> > +        socket_id = cpus->cpus[n].props.socket_id;
> > +        if (g_queue_find(socket_list, GUINT_TO_POINTER(socket_id))) {
> > +            continue;
> > +        }
> > +
> > +        g_queue_push_tail(socket_list, GUINT_TO_POINTER(socket_id));
> >           g_queue_push_tail(list,
> >               GUINT_TO_POINTER(table_data->len - pptt_start));
> >           build_processor_hierarchy_node(
> > @@ -2023,65 +2032,114 @@ void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms,
> >                * of a physical package
> >                */
> >               (1 << 0),
> > -            0, socket, NULL, 0);
> > +            0, socket_id, NULL, 0);
> >       }
> >   
> >       if (mc->smp_props.clusters_supported) {
> >           length = g_queue_get_length(list);
> >           for (i = 0; i < length; i++) {
> > -            int cluster;
> > -
> >               parent_offset = GPOINTER_TO_UINT(g_queue_pop_head(list));
> > -            for (cluster = 0; cluster < ms->smp.clusters; cluster++) {
> > +            socket_id = GPOINTER_TO_UINT(g_queue_pop_head(socket_list));
> > +
> > +            for (n = 0; n < cpus->len; n++) {
> > +                if (cpus->cpus[n].props.socket_id != socket_id) {
> > +                    continue;
> > +                }
> > +
> > +                /*
> > +                 * We have to calculate the cluster ID because it isn't
> > +                 * available in the CPU instance properties.
> > +                 */  
> Since we need cluster ID now, maybe we can simply make it supported
> in the CPU instance properties.

agreed

> 
> Thanks,
> Yanan
> > +                cluster_id = cpus->cpus[n].props.thread_id /
> > +                             (ms->smp.cores * ms->smp.threads);
> > +                if (g_queue_find(cluster_list, GUINT_TO_POINTER(cluster_id))) {
> > +                    continue;
> > +                }
> > +
> > +                g_queue_push_tail(cluster_list, GUINT_TO_POINTER(cluster_id));
> >                   g_queue_push_tail(list,
> >                       GUINT_TO_POINTER(table_data->len - pptt_start));
> >                   build_processor_hierarchy_node(
> >                       table_data,
> >                       (0 << 0), /* not a physical package */
> > -                    parent_offset, cluster, NULL, 0);
> > +                    parent_offset, cluster_id, NULL, 0);
> >               }
> >           }
> >       }
> >   
> >       length = g_queue_get_length(list);
> >       for (i = 0; i < length; i++) {
> > -        int core;
> > -
> >           parent_offset = GPOINTER_TO_UINT(g_queue_pop_head(list));
> > -        for (core = 0; core < ms->smp.cores; core++) {
> > -            if (ms->smp.threads > 1) {
> > -                g_queue_push_tail(list,
> > -                    GUINT_TO_POINTER(table_data->len - pptt_start));
> > -                build_processor_hierarchy_node(
> > -                    table_data,
> > -                    (0 << 0), /* not a physical package */
> > -                    parent_offset, core, NULL, 0);
> > -            } else {
> > +        if (!mc->smp_props.clusters_supported) {
> > +            socket_id = GPOINTER_TO_UINT(g_queue_pop_head(socket_list));
> > +        } else {
> > +            cluster_id = GPOINTER_TO_UINT(g_queue_pop_head(cluster_list));
> > +        }
> > +
> > +        for (n = 0; n < cpus->len; n++) {
> > +            if (!mc->smp_props.clusters_supported &&
> > +                cpus->cpus[n].props.socket_id != socket_id) {
> > +                continue;
> > +            }
> > +
> > +            /*
> > +             * We have to calculate the cluster ID because it isn't
> > +             * available in the CPU instance properties.
> > +             */
> > +            id = cpus->cpus[n].props.thread_id /
> > +                (ms->smp.cores * ms->smp.threads);
> > +            if (mc->smp_props.clusters_supported && id != cluster_id) {
> > +                continue;
> > +            }
> > +
> > +            core_id = cpus->cpus[n].props.core_id;
> > +            if (ms->smp.threads <= 1) {
> >                   build_processor_hierarchy_node(
> >                       table_data,
> >                       (1 << 1) | /* ACPI Processor ID valid */
> >                       (1 << 3),  /* Node is a Leaf */
> > -                    parent_offset, uid++, NULL, 0);
> > +                    parent_offset, core_id, NULL, 0);
> > +                continue;
> >               }
> > +
> > +            if (g_queue_find(core_list, GUINT_TO_POINTER(core_id))) {
> > +                continue;
> > +            }
> > +
> > +            g_queue_push_tail(core_list, GUINT_TO_POINTER(core_id));
> > +            g_queue_push_tail(list,
> > +                GUINT_TO_POINTER(table_data->len - pptt_start));
> > +            build_processor_hierarchy_node(
> > +                table_data,
> > +                (0 << 0), /* not a physical package */
> > +                parent_offset, core_id, NULL, 0);
> >           }
> >       }
> >   
> >       length = g_queue_get_length(list);
> >       for (i = 0; i < length; i++) {
> > -        int thread;
> > -
> >           parent_offset = GPOINTER_TO_UINT(g_queue_pop_head(list));
> > -        for (thread = 0; thread < ms->smp.threads; thread++) {
> > +        core_id = GPOINTER_TO_UINT(g_queue_pop_head(core_list));
> > +
> > +        for (n = 0; n < cpus->len; n++) {
> > +            if (cpus->cpus[n].props.core_id != core_id) {
> > +                continue;
> > +            }
> > +
> > +            thread_id = cpus->cpus[n].props.thread_id;
> >               build_processor_hierarchy_node(
> >                   table_data,
> >                   (1 << 1) | /* ACPI Processor ID valid */
> >                   (1 << 2) | /* Processor is a Thread */
> >                   (1 << 3),  /* Node is a Leaf */
> > -                parent_offset, uid++, NULL, 0);
> > +                parent_offset, thread_id, NULL, 0);
> >           }
> >       }
> >   
> >       g_queue_free(list);
> > +    g_queue_free(core_list);
> > +    g_queue_free(cluster_list);
> > +    g_queue_free(socket_list);
> >       acpi_table_end(linker, &table);
> >   }
> >     
>