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 <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20170224182844.32452-15-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert 2017-02-24 18:28:42 +00:00
parent 61a502128b
commit 7e8cafb713

View File

@ -81,6 +81,17 @@ static bool ufd_version_check(int ufd)
return false; 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; return true;
} }
@ -115,7 +126,6 @@ bool postcopy_ram_supported_by_host(void)
if (!ufd_version_check(ufd)) { if (!ufd_version_check(ufd)) {
goto out; 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 * userfault and mlock don't go together; we'll put it back later if