Re: [Qemu-devel] [RFC 0/9] generate dynamic _CRS for motherboard resources

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 17 Feb 2014 09:32:35 +0100
Gerd Hoffmann <kraxel@redhat.com> wrote:

> On So, 2014-02-16 at 17:53 +0200, Michael S. Tsirkin wrote:
> > On Fri, Feb 07, 2014 at 01:51:27PM +0100, Igor Mammedov wrote:
> > > Since introduction of PCIHP, it became problematic to
> > > punch hole in PCI0._CRS statically since PCI hotplug
> > > region size became runtime changeable.
> > 
> > What makes it runtime changeable?
> 
> machine type.  q35 / piix map them at different locations.
> 
> Also we might want to this also for devices which are
> runtime-configurable (isa-debugcon, pvpanic, ...).
I'd convert simple devices that conditionally enabled at
startup time, from static definition + patching into
completely dynamically generated when device present.
For example pvpanic falls in to this category.

That would result in smaller ACPI tables guest has to deal with.

> 
> cheers,
>   Gerd
> 
>