Re: Question regarding SLAB corruption

[Keir Fraser <keir@xensource.com>]

On 8/7/07 11:05, "Lukas Hejtmanek" <xhejtman@ics.muni.cz> wrote:

>> It could be DMAing randomly. Is there a debug flag in the driver to provide
>> verbose tracing? Or you could add tracing (or audit) the places that it
>> initiates DMA and see whether the DMA addresses are correctly calculated.
> 
> Yeah, I will try to add tracing to DMA actions. However, can address bars
> influence DMA actions, mainly if provided by Dom0 for DomU.
> 
> More precisely, if I bypass address bars logic (in pciback) and write the
> addresses directly to the PCI config space, isn't Xen Dom0 confused and
> possibly sets up DMA transfers incorrectly? I.e., which part physically sets
> up the DMA -- Dom0 or DomU?

DomU sets up its own DMAs. The BARs do not come into it (except that they
will indicate where device registers are, and that's how the DMA is
programmed).

It sounds like you have this SLAB bug in dom0 and domU right now. You should
get your driver working properly in dom0 before taking the next step of
debugging it in domU. Otherwise you are trying to track down multiple
problems simultaneously.

 -- Keir