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Re: [Qemu-ppc] [PATCH] pseries: Limit PCI host bridge "index" value
From: |
Alexander Graf |
Subject: |
Re: [Qemu-ppc] [PATCH] pseries: Limit PCI host bridge "index" value |
Date: |
Thu, 29 Jan 2015 14:12:41 +0100 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 |
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 <address@hidden>
Thanks, applied to ppc-next.
Alex