Re: [Qemu-devel] [PATCH] pseries: Limit PCI host bridge "index" value

[Alexander Graf <agraf@suse.de>]

On 14.01.15 03:33, David Gibson wrote:
> pseries guests can have large numbers of PCI host bridges.  To avoid the
> user having to specify a number of different configuration values for every
> one, the device supports an "index" property which is a shorthand setting
> the various window and configuration addresses from a predefined sensible
> set.
> 
> There are some problems with the details at present:
>   * The "index" propery is signed, but negative values will create PCI
> windows below where we expect, potentially colliding with other devices
>   * No limit is imposed on the "index" property and large values can
> translate to extremely large window addresses.  With PCI passthrough in
> particular this can mean we exceed various mapping and physical address
> limits causing the guest host bridge to not work in strange ways.
> 
> This patch addresses this, by making "index" unsigned, and imposing a
> limit.  Currently the limit allows indices from 0..255 which is probably
> enough host bridges for the time being.  It's fairly easy to extend if
> we discover we need more.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Thanks, applied to ppc-next.


Alex