On 06/02/2017 18:33, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > We need extra Linux kernel support (~4.11) to support userfaults > on hugetlbfs; check for them. > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > Reviewed-by: Juan Quintela <quint...@redhat.com> > --- > migration/postcopy-ram.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index 6b30b43..102fb61 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -81,6 +81,17 @@ static bool ufd_version_check(int ufd) > return false; > } > > + if (getpagesize() != ram_pagesize_summary()) { > + bool have_hp = false; > + /* We've got a huge page */ > +#ifdef UFFD_FEATURE_MISSING_HUGETLBFS > + have_hp = api_struct.features & UFFD_FEATURE_MISSING_HUGETLBFS; > +#endif > + if (!have_hp) { > + error_report("Userfault on this host does not support huge > pages"); > + return false; > + } > + } > return true; > } > > @@ -115,7 +126,6 @@ bool postcopy_ram_supported_by_host(void) > if (!ufd_version_check(ufd)) { > goto out; > } > - /* TODO: Only allow huge pages if the kernel supports it */ > > /* > * userfault and mlock don't go together; we'll put it back later if > Reviewed-by: Laurent Vivier <lviv...@redhat.com>