Re: [PATCH v3 4/4] hw/arm/virt: Unify ACPI processor ID in MADT and SRAT table

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 23 Mar 2022 15:24:38 +0800
Gavin Shan <gshan@redhat.com> wrote:

> The value of the following field has been used in ACPI PPTT table
> to identify the corresponding processor. This takes the same field
> as the ACPI processor ID in MADT and SRAT tables.
> 
>   ms->possible_cpus->cpus[i].props.thread_id

thread-id could be something different than ACPI processor ID
(to be discussed in the first patch).

I'd prefer to keep both decoupled, i.e. use [0 - possible_cpus->len)
for ACPI processor ID as it's done with x86 madt/srat and ACPI CPU
hotplug code. So we could reuse at least the later when implementing
CPU hotplug for arm/virt and it's good from consistency point of view.

> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
>  hw/arm/virt-acpi-build.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 449fab0080..7fedb56eea 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -534,13 +534,16 @@ build_srat(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  
>      for (i = 0; i < cpu_list->len; ++i) {
>          uint32_t nodeid = cpu_list->cpus[i].props.node_id;
> +        uint32_t thread_id = cpu_list->cpus[i].props.thread_id;
> +
>          /*
>           * 5.2.16.4 GICC Affinity Structure
>           */
>          build_append_int_noprefix(table_data, 3, 1);      /* Type */
>          build_append_int_noprefix(table_data, 18, 1);     /* Length */
>          build_append_int_noprefix(table_data, nodeid, 4); /* Proximity Domain */
> -        build_append_int_noprefix(table_data, i, 4); /* ACPI Processor UID */
> +        build_append_int_noprefix(table_data,
> +                                  thread_id, 4); /* ACPI Processor UID */
>          /* Flags, Table 5-76 */
>          build_append_int_noprefix(table_data, 1 /* Enabled */, 4);
>          build_append_int_noprefix(table_data, 0, 4); /* Clock Domain */
> @@ -704,6 +707,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  {
>      int i;
>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
> +    MachineState *ms = MACHINE(vms);
>      const MemMapEntry *memmap = vms->memmap;
>      AcpiTable table = { .sig = "APIC", .rev = 3, .oem_id = vms->oem_id,
>                          .oem_table_id = vms->oem_table_id };
> @@ -725,8 +729,9 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>      build_append_int_noprefix(table_data, vms->gic_version, 1);
>      build_append_int_noprefix(table_data, 0, 3);   /* Reserved */
>  
> -    for (i = 0; i < MACHINE(vms)->smp.cpus; i++) {
> +    for (i = 0; i < ms->smp.cpus; i++) {
>          ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(i));
> +        uint32_t thread_id = ms->possible_cpus->cpus[i].props.thread_id;
>          uint64_t physical_base_address = 0, gich = 0, gicv = 0;
>          uint32_t vgic_interrupt = vms->virt ? PPI(ARCH_GIC_MAINT_IRQ) : 0;
>          uint32_t pmu_interrupt = arm_feature(&armcpu->env, ARM_FEATURE_PMU) ?
> @@ -743,7 +748,8 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>          build_append_int_noprefix(table_data, 76, 1);   /* Length */
>          build_append_int_noprefix(table_data, 0, 2);    /* Reserved */
>          build_append_int_noprefix(table_data, i, 4);    /* GIC ID */
> -        build_append_int_noprefix(table_data, i, 4);    /* ACPI Processor UID */
> +        build_append_int_noprefix(table_data,
> +                                  thread_id, 4);        /* ACPI Processor UID */
>          /* Flags */
>          build_append_int_noprefix(table_data, 1, 4);    /* Enabled */
>          /* Parking Protocol Version */