On Tue, Feb 19, 2013 at 01:11:51PM -0700, Alex Williamson wrote: > On Tue, 2013-02-19 at 18:38 +1100, David Gibson wrote: > > On Mon, Feb 18, 2013 at 10:24:00PM -0700, Alex Williamson wrote: > > > On Mon, 2013-02-18 at 17:15 +1100, Alexey Kardashevskiy wrote: [snip] > > > Adding the window size to sysfs seems more readily convenient, > > > but is it so hard for userspace to open the files and call a couple > > > ioctls to get far enough to call IOMMU_GET_INFO? I'm unconvinced the > > > clutter in sysfs more than just a quick fix. Thanks, > > > > And finally, as Alexey points out, isn't the point here so we know how > > much rlimit to give qemu? Using ioctls we'd need a special tool just > > to check the dma window sizes, which seems a bit hideous. > > Is it more hideous that using iommu groups to report a vfio imposed > restriction? Are a couple open files and a handful of ioctls worse than > code to parse directory entries and the future maintenance of an > unrestricted grab bag of sysfs entries?
The fact that the memory is locked is a vfio restriction, but the
actual dma window size is, genuinely, a property of the group.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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