Re: [Qemu-devel] [patch 13/18] qemu: warn if PCI region is not power of two

[Paul Brook <paul@codesourcery.com>]

On Wednesday 04 February 2009, Marcelo Tosatti wrote:
> Otherwise the PCI size for such regions can be calculated erroneously.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>
> Index: trunk/hw/pci.c
> ===================================================================
> --- trunk.orig/hw/pci.c
> +++ trunk/hw/pci.c
> @@ -249,6 +249,11 @@ void pci_register_io_region(PCIDevice *p
>
>      if ((unsigned int)region_num >= PCI_NUM_REGIONS)
>          return;
> +
> +    if (size & (size-1))
> +        term_printf("WARNING: PCI region size must be pow2 "
> +                    "type=0x%x, size=0x%x\n", type, size);
> +

This should be an error. It is a requirement of the PCI spec, and not 
something that's user configurable. Any odd sizes indicate a fairly serious 
bug elsewhere in qemu.

Paul