[Qemu-devel] [PATCH 7/7] Implement cpu hot-add using device_add monitor command

[Igor Mammedov <imammedo@redhat.com>]

Adds ability to hot-add cpus if guest was started with options
    -smp X,maxcpus=Y
where X < Y.
For simplicity sake this implementation doesn't allow to add specific
cpu but rather it adds the next not yet plugged cpu.

For adding cpu just execute following command in monitor:
    device_add cpu-pc
If guest was started with a specific cpu model, then add option model
to cmonitor command. for example:
    device_add cpu-pc,model="host"

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 hw/pc.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index ec50f16..5923549 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -44,6 +44,8 @@
 #include "ui/qemu-spice.h"
 #include "memory.h"
 #include "exec-memory.h"
+#include "cpus.h"
+#include "kvm.h"
 
 /* output Bochs bios info messages */
 //#define DEBUG_BIOS
@@ -941,6 +943,10 @@ static int cpu_device_init(ICCBusDevice *dev)
 #endif
     }
 
+    if (runstate_is_running()) {
+        pause_all_vcpus();
+    }
+
     if (cpu_x86_init_inplace(env, cpu->model) < 0) {
         return -1;
     }
@@ -949,6 +955,11 @@ static int cpu_device_init(ICCBusDevice *dev)
         env->apic_state = apic_init(env, env->cpuid_apic_id);
     }
 
+    cpu_synchronize_post_init(env);
+    if (runstate_is_running()) {
+        resume_all_vcpus();
+        acpi_cpu_hot_plug(env->cpuid_apic_id, 1);
+    }
     return 0;
 }
 
-- 
1.7.7.6