Re: [PATCH v3 2/2][BNX2]: Add iSCSI support to BNX2 devices.

[FUJITA Tomonori <tomof@acm.org>]

On Sat, 8 Sep 2007 13:00:36 +0100
Christoph Hellwig <hch@infradead.org> wrote:

> On Sat, Sep 08, 2007 at 07:32:27AM -0400, Jeff Garzik wrote:
> > FUJITA Tomonori wrote:
> > >Yeah, iommu code ignores the lld limitations (the problem is that the
> > >lld limitations are in request_queue and iommu code can't access to
> > >request_queue). There is no way to tell iommu code about the lld
> > >limitations.
> > 
> > 
> > This fact very much wants fixing.
> 
> 
> Absolutely.  Unfortunately everyone wastes their time on creating workarounds
> instead of fixing the underlying problem.

Any ideas on how to fix this?

I chatted to Jens and James on this last week.

- we could just copies the lld limitations to device structure. it's
hacky but device structure already has hacky stuff.

- we could just link device structure to request_queue structure so
that iommu code can see request_queue structure.

- we could remove the lld limitations in request_queue strucutre and
have a new strucutre (something like struct io_restrictions). then
somehow we could link the new structure with request_queue and device
strucutres.