Re: [Qemu-devel] [PATCH 0/2 v2] pc: inform SeaBIOS where 64-bit PCI hole begins

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

On Tue, Oct 29, 2013 at 01:57:33PM +0100, Igor Mammedov wrote:
> * simplify PCI address space mapping into system address space,
>   replacing code duplication in piix/q53 PCs with a helper function
> 
> * add fw_cfg 'etc/pcimem64-minimum-address' to allow QEMU reserve
>   additional address space before 64-bit PCI hole. Which will be
>   need for reserving memory hotplug region in highmem.
>   SeaBIOS counterpart: http://patchwork.ozlabs.org/patch/283623/

I'd like to see if we can figure out the migration issue with
memory layout. Because if we do, and get rid of the separate 64 bit
region as a concept, exposing the start of this non-existent
region in FW CFG will make very little sense IMHO.

> v2:
>  *  use negative priority to map PCI address space under RAM memory
>     regions which allows simplify code by removing pci_hole &
>     pci_hole64 memory region aliases
> 
> Series depends on:
>  "memory: Change MemoryRegion priorities from unsigned to signed:
> 
> Git tree for testing:
>   https://github.com/imammedo/qemu/commits/pcimem64-minimum-address-v2
> 
> Igor Mammedov (1):
>   pc: add 'etc/pcimem64-minimum-address' fw_cfg interface to SeaBIOS
> 
> Michael S. Tsirkin (1):
>   pc: map PCI address space as catchall region for not mapped addresses
> 
>  hw/i386/pc.c              |   28 ++++++++++++++++------------
>  hw/i386/pc_piix.c         |    2 --
>  hw/pci-host/piix.c        |   27 +++++----------------------
>  hw/pci-host/q35.c         |   28 ++++++----------------------
>  include/hw/i386/pc.h      |   15 +++------------
>  include/hw/pci-host/q35.h |    2 --
>  6 files changed, 30 insertions(+), 72 deletions(-)