Re: [Qemu-devel] [PULL for-1.8 1/2] pc: disable pci-info

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Nov 26, 2013 at 09:12:50AM +0100, Laszlo Ersek wrote:
> On 11/18/13 12:53, Michael S. Tsirkin wrote:
> > From: Igor Mammedov <imammedo@redhat.com>
> > 
> > The BIOS that we ship in 1.7 does not use pci info
> > from host and so far isn't going to use it.
> > Taking in account problems it caused see 9604f70fdf and
> > to avoid future incompatibility issues, it's safest to
> > disable that interface by default for all machine types
> > including 1.7 as it was never exposed/used by guest.
> > And properly remove/cleanup it during 1.8 development cycle.
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >  hw/i386/pc_piix.c | 2 +-
> >  hw/i386/pc_q35.c  | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> etc/pci-info is precisely the form and contents that OVMF needs to
> download ACPI tables from qemu.
> 
> <http://sourceforge.net/mailarchive/forum.php?thread_name=1385450282-27007-3-git-send-email-lersek%40redhat.com&forum_name=edk2-devel>
> 
> Please keep this exported in 1.8, for OVMF's sake.
> 
> Thanks
> Laszlo

This pull request was misnamed, it was merged for 1.7.
Problem is pci-info can't be implemented correctly as defined:
for example we don't know where does MMCONFIG resize before
it is configured.
This patch was acked by several people so we'll need a stronger justification
for re-introducing it.
seabios manages to enumerate PCI with information exported from qemu
so why can't OVMF?

I think it's down to other qemu bugs (such as _CRS not covering
all of PCI memory), we shall just fix them.

-- 
MST