Re: [Qemu-devel] [PATCH V2] pci: fixes to allow booting from extra root pci buses.

From: Kevin O'Connor <kevin@koconnor.net>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>,
	seabios@seabios.org, Laszlo Ersek <lersek@redhat.com>,
	Gerd Hoffmann <kraxel@redhat.com>,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH V2] pci: fixes to allow booting from extra root pci buses.
Date: Sun, 14 Jun 2015 14:21:31 -0400	[thread overview]
Message-ID: <20150614182131.GA27255@morn.localdomain> (raw)
In-Reply-To: <20150614195525-mutt-send-email-mst@redhat.com>

On Sun, Jun 14, 2015 at 08:06:22PM +0200, Michael S. Tsirkin wrote:
> To summarise, you feel that modifying bus id without reordering
> bus ids between roots is likely, modifications that would
> cause reordering are unlikely, thus counting bus ids
> in order gives a stable index. Is that right?

Yes.

> To be on the safe side, it would be nice to have bios skip some
> fields/properties when parsing paths, so that if we want to use another
> id in the future, we can supply both id types.  I haven't looked at the
> parsing code - maybe it does this already?

SeaBIOS already does that.  (SeaBIOS doesn't parse the bootorder file
- it generates a "glob" like pattern for each device and then sees if
that pattern matches a line in the bootorder file.)

Also, I don't have a strong objection to Laszlo's SeaBIOS patch (the
one that does the runningOnQEMU() check).  (I still think it's quirky
to use bus-id in the file, but it's not a show stopper if it's just
for QEMU.)

-Kevin