Re: netfront pv driver building

[Ian Campbell <Ian.Campbell@XenSource.com>]

On Wed, 2007-01-24 at 13:46 +0000, Jan Beulich wrote:
> netfront requires the symbol __supported_pte_mask when PAE is enabled in the
> kernel being built for. That symbol, however, isn't being exported, and it doesn't
> seem likely that mainline would want to see this get exported (after all, the
> general assumption is that the page table handling inline functions and macros
> are supposed to be used only by the memory management code).

I committed a patch the other day which defines __supported_pte_mask to
~0ULL when building the unmodified drivers. It is 13555:687b1120765e in
xen-unstable. You are using 3.0.4-testing?

(it occurs to me now that I might have wanted ~PAGE_NX for greatest
compatibility, need to think about that a bit more.)

I wonder how this affects the PV-on-PV version when built as a module.
Presumably we export the symbol in the Xen tree but as you say that is
unlikely to go upstream.

> Additionally, both uses are inside a conditional depending upon
> !XENFEAT_auto_translated_physmap, which hence can't ever be true if this
> code is being built as pv driver. Wouldn't it hence make sense to #ifdef these
> code blocks, or to enhance xen/features.h so that checks for those features
> that are always on in hvm and return a constant 1 rather than using the
> xen_features array.

Is it necessary with the fix I mentioned above?

Ian.