[PATCH RFC 13/22] arm/cpuhp: Add ACPI _MAT entry for Processor object

[Salil Mehta]

Adds a function which builds the ACPI _MAT entry for processor objects. This
shall be called from the cpus AML for all possible vcpus.

The entry is passed to the guest kernel with ACPI_MADT_GICC_ENABLED flag when
it evaluates _MAT object. OSPM evaluates _MAT object in context to the cpu
hotplug event.

Co-developed-by: Keqian Zhu <zhukeqi...@huawei.com>
Signed-off-by: Salil Mehta <salil.me...@huawei.com>
---
 hw/acpi/cpu.c            |  5 +++++
 hw/arm/virt-acpi-build.c | 20 ++++++++++++++++++++
 include/hw/arm/virt.h    |  1 +
 3 files changed, 26 insertions(+)

diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index 867fdd6993..a79dc65120 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -565,6 +565,11 @@ void build_cpus_aml(Aml *table, MachineState *machine, 
CPUHotplugFeatures opts,
                 apic->flags = cpu_to_le32(1);
                 break;
             }
+            case ACPI_APIC_GENERIC_CPU_INTERFACE: {
+                AcpiMadtGenericCpuInterface *gicc = (void *)madt_buf->data;
+                gicc->flags = cpu_to_le32(1);
+                break;
+            }
             default:
                 assert(0);
             }
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index c654e2c9a3..354fd775f9 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -593,6 +593,22 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, 
VirtMachineState *vms)
 }
 
 /* MADT */
+static void
+build_mat_entry(AcpiDeviceIf *adev, int uid, const CPUArchIdList *arch_ids,
+                    GArray *entry)
+{
+    AcpiMadtGenericCpuInterface *gicc = acpi_data_push(entry,sizeof(*gicc));
+    MachineState *ms = MACHINE(qdev_get_machine());
+    CPUArchIdList *possible_cpus = ms->possible_cpus;
+
+    /* fill the relevant fields of _MAT entry for GICC */
+    gicc->type = ACPI_APIC_GENERIC_CPU_INTERFACE;
+    gicc->length = sizeof(*gicc);
+    gicc->cpu_interface_number = cpu_to_le32(uid);
+    gicc->arm_mpidr = possible_cpus->cpus[uid].arch_id;
+    gicc->uid = cpu_to_le32(uid);
+}
+
 static void
 build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
 {
@@ -741,6 +757,10 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, 
VirtMachineState *vms)
              .acpi_1_compatible = false,
              .has_legacy_cphp = false
         };
+        AcpiDeviceIfClass *adevc;
+        /* _MAT entry shall be used within cpus aml */
+        adevc = ACPI_DEVICE_IF_CLASS(DEVICE_GET_CLASS(vms->acpi_dev));
+        adevc->madt_cpu = build_mat_entry;
 
         build_cpus_aml(scope, ms, opts, memmap[VIRT_CPUHP_ACPI].base,
                        "\\_SB", NULL, AML_SYSTEM_MEMORY);
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index e0bd9df69d..e8468d8cf6 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -37,6 +37,7 @@
 #include "hw/block/flash.h"
 #include "sysemu/kvm.h"
 #include "hw/intc/arm_gicv3_common.h"
+#include "hw/acpi/acpi_dev_interface.h"
 
 #define NUM_GICV2M_SPIS       64
 #define NUM_VIRTIO_TRANSPORTS 32
-- 
2.17.1