Re: [Qemu-devel] [PATCH v4 5/5] i8259: fix dynamically masking slave IRQs with IMR register

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-09-03 17:42, Juan Quintela wrote:
> Avi Kivity <avi@redhat.com> wrote:
>> On 09/03/2012 11:40 AM, Andreas Färber wrote:
>>> Am 03.09.2012 04:56, schrieb Matthew Ogilvie:
>>>> diff --git a/hw/i8259_common.c b/hw/i8259_common.c
>>>> index ab3d98b..dcde5f2 100644
>>>> --- a/hw/i8259_common.c
>>>> +++ b/hw/i8259_common.c
>>> [...]
>>>> @@ -111,6 +112,7 @@ static const VMStateDescription vmstate_pic_common = {
>>>>          VMSTATE_UINT8(isr, PICCommonState),
>>>>          VMSTATE_UINT8(priority_add, PICCommonState),
>>>>          VMSTATE_UINT8(irq_base, PICCommonState),
>>>> +        VMSTATE_UINT8(icw3, PICCommonState),
>>>>          VMSTATE_UINT8(read_reg_select, PICCommonState),
>>>>          VMSTATE_UINT8(poll, PICCommonState),
>>>>          VMSTATE_UINT8(special_mask, PICCommonState),
>>>
>>> Additional VMState needs to be versioned by incrementing .version_id and
>>> by specifying the new version number here. Otherwise it breaks migration.
> 
> For the subsection, only sending this when icw3 != 0 is enough?  I am
> searching for a test about when we need to send it.

See my reply on this topic in the other branch of this thread.

> 
>> And incrementing the version ID breaks backwards migration.  The correct
>> solution is subsections, copying Juan and booking a trip to the Mariana
>> trench.
> 
> Book also for me, no need for the return ticket.
> 

Hey, this scenario is rather harmless (famous last words...). ;)

Jan

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