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Date: Wed, 23 May 2012 22:20:19 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Baron <jbaron@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>, bhelgaas@google.com,
	linux-pci@vger.kernel.org
Subject: Re: [PATCH] pci hotplug: rescan bridge after device hotplug
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On Wed, May 23, 2012 at 10:08:41PM +0300, Michael S. Tsirkin wrote:
> On Wed, May 23, 2012 at 02:44:49PM -0400, Jason Baron wrote:
> > On Wed, May 23, 2012 at 10:16:06AM -0700, Yinghai Lu wrote:
> > > On Wed, May 23, 2012 at 8:53 AM, Jason Baron <jbaron@redhat.com> wrote:
> > > >> > but still would prefer you to make qemu to support pciehp.
> > > >>
> > > >> another solution could be:
> > > >>
> > > >> in qemu acpi dsdt, you could set bridge size for new added bridge.
> > > >>
> > > >> current pbus_size_mem() will not shrink the old bridge resource size.
> > > >
> > > > ok, I also tried hard-wiring the bridge io/mem base and limit registers on the
> > > > qemu side. That seems to work without any guest-side hotplug code changes. And
> > > > would seem to be more flexible than putting the limits in acpi.
> > > 
> > > that should be acpi asl code or SMI work. and should make sure that
> > > range is not overlapped with resources that are used by other bridges
> > > and pci devices.
> > > 
> > 
> > Ok. So you are saying to define a 'Name (_CRS, ResourceTemplate() {
> > Memory() IO() })' block for each bridge?
> 
> We are talking about hotplugging bridges.
> This sounds strange.

However if it works it is certainly simple.