[Qemu-devel] [PATCH 4/4] target-i386: implement machine->hot_add_cpu hook

[Igor Mammedov <imammedo@redhat.com>]

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v3:
  * use machine.cpu-model option to store default value and to
    get current value when hot-adding CPU
v2:
  * override .hot_add_cpu staticaly starting with 1.5 machine
---
 hw/i386/pc.c         | 29 +++++++++++++++++++++++++++++
 hw/i386/pc_piix.c    |  1 +
 hw/i386/pc_q35.c     |  1 +
 include/hw/i386/pc.h |  1 +
 4 files changed, 32 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 6b3faac..b7d28d6 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -54,6 +54,7 @@
 #include "qemu/config-file.h"
 #include "hw/acpi/acpi.h"
 #include "hw/cpu/icc_bus.h"
+#include "hw/boards.h"
 
 /* debug PC/ISA interrupts */
 //#define DEBUG_IRQ
@@ -915,6 +916,33 @@ static X86CPU *pc_new_cpu(const char *cpu_model, int64_t apic_id,
     return cpu;
 }
 
+void pc_hot_add_cpu(const int64_t id, Error **errp)
+{
+    DeviceState *icc_bridge;
+    const char *cpu_model;
+    QemuOpts *machine_opts;
+    int64_t apic_id = x86_cpu_apic_id_from_index(id);
+
+    if (cpu_exists(apic_id)) {
+        error_setg(errp, "Unable to add CPU: %" PRIi64
+                   ", it already exists", id);
+        return;
+    }
+
+    if (id >= max_cpus) {
+        error_setg(errp, "Unable to add CPU: %" PRIi64
+                   ", max allowed: %d", id, max_cpus - 1);
+        return;
+    }
+
+    machine_opts = qemu_opts_find(qemu_find_opts("machine"), 0);
+    cpu_model = qemu_opt_get(machine_opts, "cpu-model");
+
+    icc_bridge = DEVICE(object_resolve_path_type("icc-bridge",
+                                                 TYPE_ICC_BRIDGE, NULL));
+    pc_new_cpu(cpu_model, apic_id, icc_bridge, errp);
+}
+
 void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
 {
     int i;
@@ -928,6 +956,7 @@ void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
 #else
         cpu_model = "qemu32";
 #endif
+        qemu_opts_set(qemu_find_opts("machine"), 0, "cpu-model", cpu_model);
     }
 
     for (i = 0; i < smp_cpus; i++) {
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 2190f0a..8e1d179 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -325,6 +325,7 @@ static QEMUMachine pc_i440fx_machine_v1_5 = {
     .alias = "pc",
     .desc = "Standard PC (i440FX + PIIX, 1996)",
     .init = pc_init_pci,
+    .hot_add_cpu = pc_hot_add_cpu,
     .max_cpus = 255,
     .is_default = 1,
     DEFAULT_MACHINE_OPTIONS,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index a926e38..fe44087 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -214,6 +214,7 @@ static QEMUMachine pc_q35_machine_v1_5 = {
     .alias = "q35",
     .desc = "Standard PC (Q35 + ICH9, 2009)",
     .init = pc_q35_init,
+    .hot_add_cpu = pc_hot_add_cpu,
     .max_cpus = 255,
     DEFAULT_MACHINE_OPTIONS,
 };
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 8a6e76c..0bbb7b4 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -79,6 +79,7 @@ void pc_register_ferr_irq(qemu_irq irq);
 void pc_acpi_smi_interrupt(void *opaque, int irq, int level);
 
 void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge);
+void pc_hot_add_cpu(const int64_t id, Error **errp);
 void pc_acpi_init(const char *default_dsdt);
 void *pc_memory_init(MemoryRegion *system_memory,
                     const char *kernel_filename,
-- 
1.8.2.1