From 7e8cafb7137502ce006cc48d0265f89399e0cb33 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 24 Feb 2017 18:28:42 +0000 Subject: [PATCH] postcopy: Check for userfault+hugepage feature We need extra Linux kernel support (~4.11) to support userfaults on hugetlbfs; check for them. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Reviewed-by: Laurent Vivier Message-Id: <20170224182844.32452-15-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- 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 6b30b43d51..102fb61485 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