On Wed, 2015-12-09 at 15:12 -0800, Stephen Hemminger wrote: > On Wed, 09 Dec 2015 23:49:59 +0100 > Thomas Monjalon <thomas.monjalon at 6wind.com> wrote: > > > 2015-12-09 13:58, Stephen Hemminger: > > > On Wed, 09 Dec 2015 22:12:33 +0100 > > > Thomas Monjalon <thomas.monjalon at 6wind.com> wrote: > > > > > > > 2015-12-09 09:55, Stephen Hemminger: > > > > > The current implementation of VFIO will not with the new no-IOMMU mode > > > > > in 4.4 kernel. The original code assumed that IOMMU group zero would > > > > > never be used. Group numbers are assigned starting at zero, and up > > > > > until now the group numbers came from the hardware which is likely > > > > > to use group 0 for system devices that are not used with DPDK. > > > > > > > > > > The fix is to allow 0 as a valid group and rearrange code > > > > > to split the return value from the group value. > > > > > > > > > > Signed-off-by: Stephen Hemminger <stephen at networkplumber.org> > > > > > --- > > > > > Why was this ignored? It was originally sent on 26 Oct 15 back > > > > > when IOMMU discussion was lively. > > > > > > > > There was no review of this patch. > > > > The patch has been marked as deferred recently when it was too late > > > > to do such feature changes in DPDK code: > > > > http://dpdk.org/dev/patchwork/patch/8035/ > > > > > > This is why as a fallback the MAINTAINER has to review the patch > > > or direct a sub-maintainer to do it. I think almost 2 months is > > > plenty of time for review. > > > > 27 October was 3 days before the feature deadline. > > And you have not pinged about it since then. > > But that's true I have missed the importance of this patch. > > Would it help to have it integrated today? > > Are you sure it won't break something else? > > Could the original VFIO submitter from Intel review it.
vfio group 0 has always been valid, but it's unlikely that you'd ever hit it in regular usage since it will typically be the root bus device. It's only with no-iommu mode in vfio that it's common, but that's getting reverted for Linux v4.4, so that may change your priorities about squeezing this in at the last minute. Thanks, Alex
