From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?ISO-8859-15?Q?Andreas_F=E4rber?= <afaerber@suse.de>
Subject: [Qemu-devel] KVM call minutes 2013-01-29 - Port I/O
Date: Wed, 30 Jan 2013 12:39:07 +0100
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Cc: KVM devel mailing list <kvm@vger.kernel.org>,
	qemu-devel <qemu-devel@nongnu.org>,
	Alexander Graf <agraf@suse.de>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	qemu-ppc <qemu-ppc@nongnu.org>,
	=?ISO-8859-15?Q?Herv=E9_Poussineau?= <hpoussin@reactos.org>,
	David Gibson <david@gibson.dropbear.id.au>,
	Gerd Hoffmann <kraxel@redhat.com>,
	Alon Levy <alevy@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Anthony Liguori <anthony@codemonkey.ws>
To: Juan Quintela <quintela@redhat.com>
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Am 29.01.2013 16:41, schrieb Juan Quintela:
> * Portio port to new memory regions?
>   Andreas, could you fill?

MemoryRegion's .old_portio mechanism requires workarounds for VGA on
ppc, affecting among others the sPAPR PCI host bridge:
http://git.qemu.org/?p=3Dqemu.git;a=3Dcommit;h=3Da3cfa18eb075c7ef78358c=
a1956fe7b01caa1724

Patches were posted and merged removing all .old_portio users but one:
hw/ioport.c:portio_list_add_1(), used by portio_list_add()

hw/isa-bus.c:    portio_list_add(piolist, isabus->address_space_io, sta=
rt);
hw/qxl.c:    portio_list_add(qxl_vga_port_list,
pci_address_space_io(dev), 0x3b0);
hw/vga.c:        portio_list_add(vga_port_list, address_space_io, 0x3b0=
);
hw/vga.c:        portio_list_add(vbe_port_list, address_space_io, 0x1ce=
);

Proposal by hpoussin was to move _list_add() code to ISADevice:
http://lists.gnu.org/archive/html/qemu-devel/2013-01/msg00508.html

Concerns:
* PCI devices (VGA, QXL) register I/O ports as well
  =3D> above patches add dependency on ISABus to machines
     -> "<benh> no mac ever had one"
  =3D> PCIDevice shouldn't use ISA API with NULL ISADevice
* Lack of avi: Who decides about memory API these days?

armbru and agraf concluded that moving this into ISA is wrong.

=3D> I will drop the remaining ioport patches from above series.

Suggestions on how to proceed with tackling the issue are welcome.

Regards,
Andreas

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