[Qemu-devel] [PATCH v5 04/16] pc: forbid BSP removal

[Igor Mammedov]

Boot CPU is assumed to always present in QEMU code, so
untile that assumptions are gone, deny removal request,
In another words QEMU won't support BSP hot-unplug.

Signed-off-by: Igor Mammedov <address@hidden>
---
v5:
  - s/1st CPU (BSP)/Boot CPU/
     Eduardo Habkost <address@hidden>
  - intialize idx to -1 and assert on it,
     Eduardo Habkost <address@hidden>
    (note: that should nexer happen in current code as we don't
     have stray CPUs and most likely never will, but it doesn't
     hurt to cautios)
---
 hw/i386/pc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 110f1bf..e15fcc1 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1757,10 +1757,18 @@ out:
 static void pc_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
                                      DeviceState *dev, Error **errp)
 {
+    int idx = -1;
     HotplugHandlerClass *hhc;
     Error *local_err = NULL;
     PCMachineState *pcms = PC_MACHINE(hotplug_dev);
 
+    pc_find_cpu_slot(pcms, CPU(dev), &idx);
+    assert(idx != -1);
+    if (idx == 0) {
+        error_setg(&local_err, "Boot CPU is unpluggable");
+        goto out;
+    }
+
     hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
     hhc->unplug_request(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
 
-- 
2.7.4