Re: [Qemu-devel] [Question] dump memory when host pci device is used by guest

[Wen Congyang <wency@cn.fujitsu.com>]

Hi, Jan Kiszka

At 10/10/2011 05:34 PM, Jan Kiszka Write:
> On 2011-10-10 11:02, Daniel P. Berrange wrote:
>> On Mon, Oct 10, 2011 at 08:52:08AM +0200, Jan Kiszka wrote:

> 
> Run gdb with "set debug remote 1" and watch the communication, it is not
> that complex. But a dump command is probably simpler for those
> scenarios, I agree.

I have implemented the command dump and reuse migration's code. But I meet a problem
when I test it.

My qemu-kvm's tree is not updated about 2 months ago, because kernel.org is down, and
I forgot to pull from github.

After I pull it from github, I find the following changes:
@@ -1523,9 +1523,7 @@ static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
 
 static const VMStateDescription vmstate_assigned_device = {
     .name = "pci-assign",
-    .fields = (VMStateField []) {
-        VMSTATE_END_OF_LIST()
-    }
+    .unmigratable = 1,
 };
 
 static void reset_assigned_device(DeviceState *dev)

Why do you remove fields from vmstate_assigned_device?
It is useful for dump because it does not check unmigratable. If vmstate_assigned_device
does not contain .fields, qemu will crash in vmstate_save_state().

Thanks
Wen Congyang

> 
> Jan
>