Re: [RFC PATCH 5/5] hw/arm/virt-acpi-build: add PPTT table

[Ying Fang]

On 2/25/2021 7:38 PM, Andrew Jones wrote:
> This is just [*] with some minor code changes
>
> [*] 
> https://github.com/rhdrjones/qemu/commit/439b38d67ca1f2cbfa5b9892a822b651ebd05c11
>
> so it's disappointing that my name is nowhere to be found on it.
>
> Also, the explanation of the DT and ACPI differences has been
> dropped from the commit message of [*]. I'm not sure why.

Will fix that. I will add SOB of you then you can help to comment on it.

> Thanks,
> drew
>
> On Thu, Feb 25, 2021 at 04:56:27PM +0800, Ying Fang wrote:
> > Add the Processor Properties Topology Table (PPTT) to present
> > CPU topology information to the guest. A three-level cpu
> > topology is built in accord with the linux kernel currently does.
> >
> > Tested-by: Jiajie Li <lijiajie11@huawei.com>
> > Signed-off-by: Ying Fang <fangying1@huawei.com>
> > ---
> >   hw/arm/virt-acpi-build.c | 50 ++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 50 insertions(+)
> >
> > diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> > index bb91152fe2..38d50ce66c 100644
> > --- a/hw/arm/virt-acpi-build.c
> > +++ b/hw/arm/virt-acpi-build.c
> > @@ -436,6 +436,50 @@ build_srat(GArray *table_data, BIOSLinker *linker, 
> > VirtMachineState *vms)
> >                    vms->oem_table_id);
> >   }
> >   
> > +static void
> > +build_pptt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
> > +{
> > +    int pptt_start = table_data->len;
> > +    int uid = 0, cpus = 0, socket = 0;
> > +    MachineState *ms = MACHINE(vms);
> > +    unsigned int smp_cores = ms->smp.cores;
> > +    unsigned int smp_threads = ms->smp.threads;
> > +
> > +    acpi_data_push(table_data, sizeof(AcpiTableHeader));
> > +
> > +    for (socket = 0; cpus < ms->possible_cpus->len; socket++) {
> > +        uint32_t socket_offset = table_data->len - pptt_start;
> > +        int core;
> > +
> > +        build_socket_hierarchy(table_data, 0, socket);
> > +
> > +        for (core = 0; core < smp_cores; core++) {
> > +            uint32_t core_offset = table_data->len - pptt_start;
> > +            int thread;
> > +
> > +            if (smp_threads <= 1) {
> > +                build_processor_hierarchy(table_data,
> > +                                          ACPI_PPTT_ACPI_PROCESSOR_ID_VALID |
> > +                                          ACPI_PPTT_ACPI_LEAF_NODE,
> > +                                          socket_offset, uid++);
> > +             } else {
> > +                build_processor_hierarchy(table_data,
> > +                                          ACPI_PPTT_ACPI_PROCESSOR_ID_VALID,
> > +                                          socket_offset, core);
> > +                for (thread = 0; thread < smp_threads; thread++) {
> > +                    build_thread_hierarchy(table_data, core_offset, uid++);
> > +                }
> > +             }
> > +        }
> > +        cpus += smp_cores * smp_threads;
> > +    }
> > +
> > +    build_header(linker, table_data,
> > +                 (void *)(table_data->data + pptt_start), "PPTT",
> > +                 table_data->len - pptt_start, 2,
> > +                 vms->oem_id, vms->oem_table_id);
> > +}
> > +
> >   /* GTDT */
> >   static void
> >   build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
> > @@ -688,6 +732,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables 
> > *tables)
> >       unsigned dsdt, xsdt;
> >       GArray *tables_blob = tables->table_data;
> >       MachineState *ms = MACHINE(vms);
> > +    bool cpu_topology_enabled = !vmc->no_cpu_topology;
> >   
> >       table_offsets = g_array_new(false, true /* clear */,
> >                                           sizeof(uint32_t));
> > @@ -707,6 +752,11 @@ void virt_acpi_build(VirtMachineState *vms, 
> > AcpiBuildTables *tables)
> >       acpi_add_table(table_offsets, tables_blob);
> >       build_madt(tables_blob, tables->linker, vms);
> >   
> > +    if (ms->smp.cpus > 1 && cpu_topology_enabled) {
> > +        acpi_add_table(table_offsets, tables_blob);
> > +        build_pptt(tables_blob, tables->linker, vms);
> > +    }
> > +
> >       acpi_add_table(table_offsets, tables_blob);
> >       build_gtdt(tables_blob, tables->linker, vms);
> >   
> > --
> > 2.23.0
>
> .