Re: [Qemu-devel] [PATCH 3/3] spapr: make irq customizable via qdev

[Markus Armbruster <armbru@redhat.com>]

David Gibson <david@gibson.dropbear.id.au> writes:

> On Tue, May 24, 2011 at 01:45:07PM +0200, Paolo Bonzini wrote:
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Alexander Graf <agraf@suse.de>
>> Cc: David Gibson <david@gibson.dropbear.id.au>
>> ---
>>  hw/spapr_vio.c |    8 +++++++-
>>  1 files changed, 7 insertions(+), 1 deletions(-)
>> 
>> diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
>> index be535d6..fee4c46 100644
>> --- a/hw/spapr_vio.c
>> +++ b/hw/spapr_vio.c
>> @@ -52,6 +52,10 @@
>>  static struct BusInfo spapr_vio_bus_info = {
>>      .name       = "spapr-vio",
>>      .size       = sizeof(VIOsPAPRBus),
>> +    .props = (Property[]) {
>> +        DEFINE_PROP_UINT32("irq", VIOsPAPRDevice, vio_irq_num, 0), \
>> +        DEFINE_PROP_END_OF_LIST(),
>> +    },
>>  };
>
> I don't see what the point of this is.  Absolute irq numbers have no
> special meaning in the XICS context, and the guest kernel will remap
> them to virtual irqs anyway.

Are the irq numbers guest-visible?  If yes, a property may be required
to keep them stable across migration.  Especially when hot-plug comes
into play.

[...]