Re: [Qemu-devel] [PATCH] usb-ohci: add vmstate descriptor

[Alexey Kardashevskiy]

On 03/24/2014 08:26 PM, Peter Maydell wrote:
> On 24 March 2014 05:53, Alexey Kardashevskiy <address@hidden> wrote:
>> On 03/23/2014 08:23 AM, Peter Maydell wrote:
>>> Oops, I hadn't noticed that; this patch is incorrect, then, because
>>> vmstate_ohci needs to include a line for the OHCIState, and we
>>> need a second vmstate struct for the OHCIState.
> 
>> Sorry but what is incorrect in the patch? I can understand that it is
>> incomplete as it is missing OHCI-specific bits from the OHCIState state and
>> I can do that but I need some hints what is really necessary. So far the
>> USB device was able to recover, only PCI bits were really needed. Thanks.
> 
> As I say above, you're not saving all the state. You need to include
> a line for the OHCIState which refers to a second vmstate struct
> to save and load the information in the OHCIState. Compare the
> EHCI save/load for an example.
> 
> You need to save everything which isn't constant (ie a device
> property or a reference to another part of the model). So for
> OHCIState you don't need to save irq, mem, as, num_ports
> or bus (the first 6 struct members), or localmem_base.
> It looks like you don't need to save USBPacket or USBPort
> fields, since the other USB controllers don't (though I'm not
> sure why not -- Gerd, do you know why this is OK?).
> You do need to save everything else. Use a third vmstate for
> 'struct OHCIPort' so you can handle the arrays of those structs
> in OHCIState.

What is a "third" vmstate? I was going to use VMSTATE_STRUCT_ARRAY.



-- 
Alexey