[RFC PATCH 06/26] hw/acpi: Don't include auxiliary vcpus in ACPI tables

[Dov Murik <dovmurik@linux.vnet.ibm.com>]

From: Tobin Feldman-Fitzthum <tobin@linux.ibm.com>

By excluding auxiliary vcpus from the ACPI tables, we hide them from the
guest OS.  This in turn allows OVMF to execute code on the auxiliary
vcpus in parallel to the OS.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@linux.ibm.com>
Signed-off-by: Dov Murik <dovmurik@linux.vnet.ibm.com>
---
 hw/acpi/cpu.c         | 10 ++++++++++
 hw/i386/acpi-build.c  |  5 +++++
 hw/i386/acpi-common.c |  5 +++++
 3 files changed, 20 insertions(+)

diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index e2317be546..d3f0a48da9 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -436,6 +436,11 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
 
         method = aml_method(CPU_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
         for (i = 0; i < arch_ids->len; i++) {
+            if (arch_ids->cpus[i].aux) {
+                /* don't build objects for auxiliary CPUs */
+                continue;
+            }
+
             Aml *cpu = aml_name(CPU_NAME_FMT, i);
             Aml *uid = aml_arg(0);
             Aml *event = aml_arg(1);
@@ -651,6 +656,11 @@ void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
 
         /* build Processor object for each processor */
         for (i = 0; i < arch_ids->len; i++) {
+            if (arch_ids->cpus[i].aux) {
+                /* don't build objects for auxiliary CPUs */
+                continue;
+            }
+
             Aml *dev;
             Aml *uid = aml_int(i);
             GArray *madt_buf = g_array_new(0, 1, 1);
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index b9190b924a..8cc7e2af3a 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1708,6 +1708,11 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
     srat->reserved1 = cpu_to_le32(1);
 
     for (i = 0; i < apic_ids->len; i++) {
+        if (apic_ids->cpus[i].aux) {
+            /* don't build objects for auxiliary CPUs */
+            continue;
+        }
+
         int node_id = apic_ids->cpus[i].props.node_id;
         uint32_t apic_id = apic_ids->cpus[i].arch_id;
 
diff --git a/hw/i386/acpi-common.c b/hw/i386/acpi-common.c
index 1f5947fcf9..7c73f3900b 100644
--- a/hw/i386/acpi-common.c
+++ b/hw/i386/acpi-common.c
@@ -91,6 +91,11 @@ void acpi_build_madt(GArray *table_data, BIOSLinker *linker,
     madt->flags = cpu_to_le32(1);
 
     for (i = 0; i < apic_ids->len; i++) {
+        if (apic_ids->cpus[i].aux) {
+            /* don't build objects for auxiliary CPUs */
+            continue;
+        }
+
         adevc->madt_cpu(adev, i, apic_ids, table_data);
         if (apic_ids->cpus[i].arch_id > 254) {
             x2apic_mode = true;
-- 
2.20.1