3 files changed, 28 insertions, 0 deletions
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 28f958dee6..197d218715 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
@@ -919,6 +920,30 @@ static X86CPU *pc_new_cpu(const char *cpu_model, int64_t apic_id,
     return cpu;
 }
 
+static const char *current_cpu_model;
+
+void pc_hot_add_cpu(const int64_t id, Error **errp)
+{
+    DeviceState *icc_bridge;
+    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;
+    }
+
+    icc_bridge = DEVICE(object_resolve_path_type("icc-bridge",
+                                                 TYPE_ICC_BRIDGE, NULL));
+    pc_new_cpu(current_cpu_model, apic_id, icc_bridge, errp);
+}
+
 void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
 {
     int i;
@@ -933,6 +958,7 @@ void pc_cpus_init(const char *cpu_model, DeviceState *icc_bridge)
         cpu_model = "qemu32";
 #endif
     }
+    current_cpu_model = cpu_model;
 
     for (i = 0; i < smp_cpus; i++) {
         cpu = pc_new_cpu(cpu_model, x86_cpu_apic_id_from_index(i),
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 251e18f9a3..fe52e5f94b 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -335,6 +335,7 @@ 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 f46295b490..52511e2b69 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -220,6 +220,7 @@ 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,
 };