Commit 7e8cafb7 authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert
Browse files

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: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Reviewed-by: default avatarLaurent Vivier <lvivier@redhat.com>
Message-Id: <20170224182844.32452-15-dgilbert@redhat.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
parent 61a50212

migration/postcopy-ram.c

+11 −1
Original line number Diff line number Diff line
@@ -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