Re: [PATCH][TOOLS] libxc: mmap fixes for BSD

[Christoph Egger <Christoph.Egger@amd.com>]

On Tuesday 10 June 2008 16:21:56 Keir Fraser wrote:
> On 10/6/08 15:09, "Christoph Egger" <Christoph.Egger@amd.com> wrote:
> > On BSD, mmap()ing files works on on-disk files but not on
> > pseudo filesystems like kernfs or procfs.
> > Therefore, attached patch mmap()s anonymous memory.
> >
> > Linux equivalents are sysfs and procfs to above BSD's pseudo-filesystems.
> > On Linux, mmap is implemented for sysfs but it is questionable to me
> > how write operations work since (most) files in sysfs have
> > static content. So this patch may fix some problems
> > with a Linux Dom0, too.
>
> We can hide special setup in mmap(/proc/xen/privcmd) that is necessary for
> later foreign mapping operations. Perhaps xc_map_foreign_ranges() interface
> could be changed so that it does the mmap(), then fills in the .va field in
> the array of entries that it is passed, and finally return the address it
> got from mmap()?
>
> This would make xc_map_foreign_ranges() similar to our other xc_map*()
> functions, which all hide the mmap() invocation inside their
> implementation.

That's fine with me.

Christoph

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